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Our 10 years of Lithium Iron Phosphate experience shared within thousands of articles, hundrends of tests and examples.


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16.02.2018
 
3.2V LFP cell initial charging

Question: How should new cells 3.2V  40AH, 60AH, 90AH, 100 AH, etc. be formed before first usage?

Answer: The new 3.2V LFP cells delivered from the warehouse are partially charged. However before the first use, it is essential to charge each cell to full capacity. The initial charging should be done with the charging current set to less than 1C (typically 0.5C), till the voltage level of 4.0 V is reached.

There is no other need for LFP 3.2V cells to be formatted or otherwise specially prepared for the use. After the first charge to full, the cell is ready to be used for use.

The above charging rule is also applied to the initial charge after the cell has been unused or stored for a long time. If not used more than 1 month, it is recommended to make again an initial charge to full.

   ...more >>

16.02.2018
 
12V LP battery balancing and charging

Question:  Can I charge the 12V LFP battery using a conventional auto-moto charger 12V?

Answer:  With most of “cheap” car battery chargers you **cannot** charge the 12V LFP battery. Cheap chargers often end charging at 14V.  As a result the LFP batteries are not charged sufficiently. In order to charge to full you need to reach above 16V.

If you have an “advanced” manageable charger, it can be used provided you can set the charge level to at least 16V.

Simply said: you can charge with any kind of charger if you make sure that the battery voltage reaches at least 16V, but does not exceed the maximum limit of 17V.

 

Question: What are the experiences of balancing 12V batteries, when, for example, four pieces of 12V/40Ah in the series?

   ...more >>

16.02.2018
 
You must charge the LiFePO4 before the first use!

Charge levels

 

You must charge before the first use!

We remind all users of the LFP cells and LP batteries that the cells and batteries MUST be charged to full voltage level BEFORE assembling into a pack and before starting to be used.

For the 3.2V cells, the full charge voltage level is 4.00V and the charging is described here.  For the 12V LP batteries the full charge voltage level is 16.00V. More details about the use of 12V batteries is here.

   ...more >>

16.02.2018
 
Using BMS to analyze the cell performance

BMS settings charge voltage

 

Why is the BMS needed for a LFP battery pack consisting of many cells?

Answer: The Battery Management System (BMS) allows you to monitor the battery pack operation. Since the battery consists of a serial string of many cells, you need to monitor each cell to prevent from deep discharge or over charge.  The BMS will give you information about the cell voltage levels and can issue warnings if there is a problem with any of the cells.

The BMS with balancing option will balance the cells (usually during charging) to make sure all cells have the same capacity (=voltage) levels.

The BMS also allows data logging so that you can see the history of the operation of the each cell in the battery. This way you can detect if there is any problem with one or more cells in the battery pack.

16.02.2018
 
Charging individual cells using the regulated (laboratory) power supply

Regulated laboratory charger

 

Charging individual cells using the regulated (laboratory) power supply

Many of the laboratory power supplies allow charging of the individual cells. Using such a regulated power supply is a suitable method for performing the initial charging or for the balancing of a single cell in a battery pack (by means of charging to a fixed voltage level).

There are usually 3 steps to follow:  1) set the target voltage (open voltage) – without the connection of the battery (3.65 at the picture), 2) start charging and set the current to be used (3.0 A at the picture), 3) when the charger reaches the target voltage – it usually starts to reduce the charging current until a low value. (3.66 V reached at 0.04A). It is a time to stop charging and disconnecting the charger.

16.02.2018
 
Initial charging FAQ

Initial charging FAQ

Check these FAQ published on our blog to understand the initial battery charging

 

We remind all users of the LFP cells and LP batteries that the cells and batteries MUST be charged to full voltage level BEFORE assembling into a pack and before starting to be used.  source

The new 3.2V LFP cells delivered from the warehouse are partially charged. However before the first use, it is essential to charge each cell to full capacitysource

   ...more >>

16.02.2018
 
Maximal voltage during Initial charge of LiFePO4

Maximal voltage during Initial charge of LiFePO4

 I want to make the initial charge of all the LiFePO4 cells to the same maximal voltage level of 4.0V. How can I do that?

 

EDIT: This article gives the example of 4.00V charge level. The same information is to applied for charging to other voltage levels: e.g. 3.65V, 3.70V, 3.80V, 3.90V. Different voltage levels may be applied for initial charging based on the manufacturer specification.

ANSWER: The best way it to find a power supply or a charger that will charge to the 4.0V directly.  Another solution is to charge using the laboratory power supply or the regulated power supply that allows to set the final (maximal) voltage limit. We suggest to check with the local electronic components suppliers for these products.

   ...more >>

16.02.2018
 
Initial charge voltage levels of LiFePO4

Voltage levels of LiFePO

 

 Initial charge voltage levels

Question: I wish to equip my workshop with the proper tools. Can you offer me following chargers: one model with cut off voltage at 3.65V, one model with cut off voltage at 3.80V and one model with cut off voltage at 4.00V?

Answer: There is no need to have so many different chargers.  The typical chargers that are sold by GWL charge to 3.65V (for single cell).  Please see some additional comments.

   ...more >>

09.02.2018
 
Sudden battery discharge

Sudden discharge of LiFePO4

FAQ: “Sudden” battery discharge

I have bought a several of LFP cells and made the pack with them to replace the lead-acid battery in my houseboat. The LFP battery was working great and it gives much more capacity than the lead acid. However after several weeks of usage, I came back after the weekend and I found out that the battery is completely discharged. Why this happen?

Please note that unlike the lead acid batteries, the LFP batteries will be completely damaged if you discharge them bellow the minimal voltage (usually >2.5V per cell, or bellow 10V for 12V battery). This may happen if you have some equipment that takes the power from the battery continually. Maybe you simply forget some light or some equipment „on“, and after few days the battery is deeply discharged and damaged forever.

   ...more >>

09.02.2018
 
Operating temperature of LFP Cells

Temperature of cells

The temperature of the LFP cells

What is the operating temperature of the LFP cells?

The operating temperature of the LFP cells is based on the specification and the application.  There are several points to be clarified in this matter.  The first to clarify is the three different temperatures in relation to the batteries.

The ambient temperature

The ambient temperature is usually given as the air temperature of any environment where the batteries and related equipment are kept.  The ambient temperature is given at the specification of the cells.  It is also called the operation temperature.

   ...more >>

30.01.2018
 
Can you recommend a device to protect a 12V LP battery?

 

Can you recommend a device to protect a 12V LP battery?

In the past we used to offer a solution called Akumon. However due to a small demand, the production of Akumon was discontinued. We also offered some Battery Guard, Battery protector, Battery protect, PowerTector, etc.  

   ...more >>

29.01.2018
 
LFP battery discharged to ZERO volts

LFP battery discharged to ZERO volts

Question: I have installed a LFP battery in my car. But when I came today to the car, the car was completely dead and all electronics stopped working. What is wrong?

Answer: What you describe may happen with the car. When the car is parked, over some days, then some equipment will discharge the battery to complete emptiness (full deep over-discharge).

  • This may happen when the small “inside” lamp is by mistake left “on”, or when the door is not closed properly. 
     
  • It may also happen that the radio was left “on” – but silent, or some other equipment drained the battery (e.g. alarm system that turned on for some reason).
     
  • In some cases the driver may accidentally forget the main headlights on, and the battery will be depleted just in a few hours.
     
  •    ...more >>

21.12.2017
 
BMS S05 - Introductory information

     

 

The BMS S05 is the next generation of modular BMS that follows the BMS2405 product line. 

The BMS2405 is designed for up to 24 cells. The  BMS S05 is stackable and allows to connect up to 144 cells (6x 24 cells). 

The BMS S05 has many rich settings and advanced functions. This BMS is designed for industrial projects and applications. Please contact us for more details to learn more about the BMS S05. 

20.12.2017
 
Checking and checking again

   

 

Any system can have a failure or an irregular operation. That is why it is important to perform multiple tests and verifications of each installation.

With battery systems the possibility of a failure or malfunction is multiplied by the number of the cells or the complexity of the installation. For a system with 2 cells, with 20 cells and with 200 cells the possibility of “problem” will be multiplied 2 times, 10 times and even 100 times.

The photo shows an example of a failure of the BMS system in a 4 cell installation. The BMS module reports a voltage and temperature that is not correct. Making a measurement of the cell proves the failure condition of the setup. In this case, caused by a defective BMS module that needs a replacement.

Our recommendation: the battery pack should have regular inspections and verifications performed.

20.12.2017
 
AutarcTech - energy storage partner in Germany

    

 

The AutarcTech company is using the cells from GWL to make the energy solution. Learn more about  AutarcTech and their products. 

AutarcTech GmbH
Technologiepark 1
91522 Ansbach
Deutschland
Tel. 0981 9878 7374
www.autarctech.de

AutarcTech GmbH, founded 2010 in Ansbach, Germany, designs and produces Lithium batteries and Batterie-Management-Systems (BMS).

Our next-generation technology sets us apart from the standard battery storage systems. Active balancing significantly increases life-expectancy of the lithium cells. This process is automatically performed when required during the entire charge and discharge cycle. The effective useable capacity of the battery is maintained. Because the energy from one cell is transferred to another, the balancing process does not rely on wasting energy to heat and becomes far more efficient.

   ...more >>

18.12.2017
 
BMS123 Smart with Victron inverters

 

Check the connection of the BMS123 Smart with thetThe Victron inverters: These are equipped with AUX I/O (allow to charge) and Temp sense (allow to discharger ports. The charge/discharge contact functionality is available only in case the Lithium assistant function is activated.

18.12.2017
 
GWL/Power BMS123 Smart - Extended Module

BMS       bms_smart

 

Extended module for advanced applications like automotive, boat and other applications using the BMS123 Smart.

The module adds the following functionality to the BMS123 Smart system:

  • 4 configurable relays - switch relay on at time or conditions
       
  • 2 individual CAN bus connections
      
  • Control Elcon/TC Charger via CAN bus interface
     
  • Broadcast BMS settings on CAN bus
      
  • Compatible with EV charging stations using the J1772/IEC 62196 protocol - adaptive charging. Extended module limits charging current to the maximum current of the charging station/vehicle.
      
  •    ...more >>

01.12.2017
 
Changing the number of cells for BMS123-Smart

 

Question: I have BMS123-Smart with 4 cells. When I add more cells, they are not recognized by the system.

Answer: You need to change the setting of the BMS123-Smart to match the number of the cell that will be recognized.

See the manual section “Hidden factory settings”.  This setting allows changing the size (rating) of the current sensor and the number of the cells in the pack.

The setting is recorded by the opening of the switch No 8, as the manual explains:

Set all switches below in the right positions for current sensor and number of cells and toggle switch 8 ON and OFF again. The hidden settings are now stored in the BMS. Set the switches back in the original positions. Please be aware it could be necessary to follow the current sensor calibration procedure again.

   ...more >>

01.12.2017
 
The condition of the safety valve

 

Question: When making the regular inspection of the battery pack, I noticed that there is some salt-like powder around the safety valve. How does it come about?

Answer:

1. New cells

All cells shipped by GWL/Power are visually inspected before delivery. They are delivered in 100% perfect condition. If you receive a new cell right from the shipment and there is some dirt or moisture around the terminal, you should contact the shipping agent and place a complaint about the damage during the delivery. You can also contact GWL/Power for additional assistance prior using the cell.

2. Used cells – regular maintenance

As concerns cells that are used for some time already, these cells should be inspected regularly every few-hundred cycles. See support info here. There should be no leakage or substance around the terminals or around the safety valve. We suggest cleaning the cells every time the inspection is made.  You can use a lightly wet cloth to clean the outside of the cells.

   ...more >>

21.11.2017
 
How often should I check my cells (or my battery pack)?

Check_cells

 

The answer depends on the type of application. See some examples.

1. Simple installations

Simple installations with one battery (12V) or with just a few cells do not need any special inspections. If you have a SMB to handle the protection of the pack, you can just monitor the voltage level. This kind of pack should be inspected once or two times in a year. Or perhaps each time after a longer pause in usage.  Note: do not forget to disconnect all electronics if not using the pack.  The pack should have a dual protection, as explained here.

 

2. Advanced installations

More advanced installations (typically with 8 cells and more) should be monitored regularly. It is recommended that the inspection of the pack is performed in these intervals (ie, after number of discharge / charge cycles):

   ...more >>

08.11.2017
 
GWL/Power battery pack demonstration

 

The simple solution for energy needs. A  2.2 kWh battery pack made from 8 cells (total 24V/90Ah), with BMS123 Smart installed. This is a basic component solution for further integration in customer projects. 

07.11.2017
 
GWL/GreenEye at Intersolar/ESS 2017

 

GWL/GreenEye at Intersolar/ESS 2017

GWL/Power was showing the 12V batteries with the GWL/GreenEye smart technology for monitoring using the mobile phone application. 

07.11.2017
 
LTO cell specifications

 

 

 

Check the basic specifications and dimensions of the LTO cells now available for your projects. 

  • Very small capacities 0.1 to 1.3 Ah 
     
  • Middle capacities 3.4 Ah to 10Ah 
     
  • Large capacities up to 65Ah

We will be happy to supply these cells for your packs. Be sure to let us know what you need.

07.11.2017
 
LTO cell test results

 

 

 

The diagrams show the test results of the specifications of the LTO cells. 

  • Charge and discharge characteristics at different rates 
  • Discharge characteristics at different temperatures
  • Discharge characteristics measured in time scope

We will be happy to provide these cells for your applications. 

16.10.2017
 
The value of the internal resistance

 

The value of the internal resistance

Question: In your promotional materials you mention several times that the internal resistance of the LTO cells is “very low”, “lower than for the LFP cells”, is “only 1 mOhm and less”. However we have tested the internal resistance and the value is more than 20 mOhm. We think your information is not correct.

Answer:

First, note that the internal resistance of the cell is not a constant value. The internal resistance increases when the cell is fully charged and also increases when the cell is getting discharged. To measure the internal resistance for reference value, you should measure within DOD of 80% to 20%.  This means after you charge the cell to full, you let the cell discharge to 80% first and only after that you perform the tests.

   ...more >>

24.06.2015
 
SBM board - no voltage at the clamps of the load

Sometimes it is necessary to start using the SBM board by connecting the charger to P+ and P-. The SBM module is internally disconnected the same way as it is when it protects the battery pack from overcharge or overdischarge.

It is also necessary to use a suitable charger - chargers for LiFePO are inappropriate, because they need to sense the voltage first to start charging. For four LiFePO4 cells it is enough to use standard charger for car-starting lead acid batteries, or any 12V small power source from modem or stereo for example, or any other small consumer electronic which uses 12V power source.

11.05.2015
 
For more information about Battery Monitoring (SBM, CBM) please visit technical blog GWL Power

For more information about Battery Monitoring (SBM, CBM) please visit technical blog GWL Power.

21.01.2015
 
CBM1 balancing with wrong current?

Question: I had purchased 48 pc of CBM1 module and i have problem. CBM1 is working but start of balancing is too high. I mesure 3,770v but on your web site says 3,6V. I had tried several boards and the resault is the same - START VOLTAGE of BALANCING is too high.

 

Answer: Too thin wire diameter might be on fault, or mistake in soldering. Please verify the connection. 

 

Result: I had problem with thin wire. Now is everthing ok. Thank you.

25.07.2014
 
Battery Management choice

What is appropriate product for the balancing of battery cells?

----------------------------------------------------------

First, it is important to realize what the real charge current in the circuit for the end of charging.
So about voltage from 3.55V - 3,6V for Cell, here is recommended to start balancing.

We offer a variety of products, ranging from a simple module CBM1
to professional BMS system with data bus and control unit.

- CBM1 modules are passive modules for the balancing.
These modules do not solve the issue of monitoring the status of the battery.
These modules are therefore necessary to supplement with the monitoring unit CellLoger
http://www.ev-power.eu/_d1747.html
Please note, that CBU1 balancing maximum current of 1.7 A.

If the charging current of 20A for example, then the balancing 1.7 A weak,
because it will flow into the battery further difference of these currents. Thus, in this case the remaining charging current of about 18A.
So it may be required to compose multiple modules CBM1 parallel to each other, to the balancing flow increased.
See real circuit examples here:
http://gwl-power.tumblr.com/tagged/CBM
It is also   ...more >>

18.05.2013
 
Connecting cable to CellLog and PowerLog

Connecting cable to CellLog and PowerLog

Computer mother-board cable can be used to connect CellLog and PowerLog to batteries.

CellLog8 - http://www.ev-power.eu/_d1747.html

PowerLog 6S - http://www.ev-power.eu/_d2116.html

28.01.2013
 
RT-BMS Summary of Technical Information and FAQ

RT-BMS Summary of Technical Information and FAQ

Check the updated document with the summary of the technical information, sepcification and FAQ for the RT-BMS system.

http://www.ev-power.eu/docs/pdf/GWL/GWL-RT-BMS-TECH-EN.pdf

The RT-BMS pricing is here:
http://www.ev-power.eu/RT-BMS-System/

27.01.2013
 
The BMS123 control software features

The BMS123 control software features

The BMS123 software screen (called dashboard) can display the min and max voltage level of the cells in the pack. When you position the mouse pointer over the number, you can see the actual number of the cell that has the MIN/MAX value.

The same status information is for the temperature of the cells.

12.01.2013
 
The 5 kWh Universal Energy Storage Setup

The 5 kWh Universal Energy Storage Setup

A practical realization of a mid-sized energy storage solution with 5 kWh of energy capacity. The modular design to work with the 230V AC grid.

The practical demonstration of the basic components to realize the energy storage solution with an easy expansion and many options to increase the size of the storage and the power output.
 
Components description of the universal energy storage

* Lithium Battery Pack 36V
Battery pack 36V 130Ah made of 12 units of finely balanced  SE130AHA LiFePO4 cells. The nominal capacity is 5 KWh of energy (38V x 130Ah).  Bigger sized cells can be easily used to increase the total capacity of the storage.
http://www.ev-power.eu/_d2904.html (USD180 per unit, total USD 2160 for 12 pcs)
 
* BMS system - BMS123 Solution 
The BMS system protects the batteries against deep discharge and against over charge. It also monitors every cell and provides data to the BMS Main Controller. Each cell has the BMS Cell Module installed. The setting is set for 44V as max charge voltage (3.70V per cell) and 35V as deep discharge voltage (2.95V per cell). The BMS is powered from a 12V battery independently of the main power battery.
http://www.ev-power.eu/BMS123-System/ (USD430 Main Unit, USD200 Cell Modules, USD150 additional components)
 
* DC contactor relay
The relay is designed to disconnect the DC/AC inverters from the batteries in case of deep voltage discharge.  The DC contactor is managed by the BMS Main Controller. http://www.ev-power.eu/_d2649.html (USD20)
 
* DC/AC Grid-tied   ...more >>

17.12.2012
 
BMS123 - a complete BMS solution

Get the revolutionary BMS system now!

The 123BMS is the latest innovative solution for the lithium cell and battery pack monitoring and management.  The 123BMS brings to you the complete system for charging and balancing or LiFePO4/LiFeYPO4 cells and batteries.  

Simple installation, easy settings, easy and reliable operation.

In this fully modular system each cell is equipped with a small size circuit-board. Using only a single wire (or twisted wire) these boards are linked to the BMS Main Controller. The controller gathers all relevant data (the number of cells, cell-address, cell-voltage, cell temperature, bypass-current and total-voltage of the battery-pack) in order to control the operation of the battery pack.

The TOP reasons why to use the 123BMS

  • Monitoring and balancing function for each cell
  • Small size board installed directly at the terminals of each cell
  • Single wire communication. Easy to assemble the battery pack
  • Excellent pricing ratio: robust and reliable system at good price
  • Direct connection and management of the ELCON chargers (TC Charger models)
  •    ...more >>

07.12.2012
 
RT-BMS cooler installation

RT-BMS cooler installation

The photo shows the design of aluminum cooling plate to install the RT-BMS high power modules on top of the 200AH cells

03.12.2012
 
BMS123 - Current and Fuel Meters

BMS123 - Current and Fuel Meters

With these analog meters you can get an easy indication of the batery capacity and the output current.

http://www.ev-power.eu/BMS123-System/

03.12.2012
 
Check the BMS123 manual

BMS123 - Components of the system

The BMS123 system contains these components: the Main Controller, the Current Sensor, the Cell Modules.

Check the BMS123 manual
http://www.ev-power.eu/docs/pdf/BMS123_Manual_v1_0.pdf

Download the BMS123 software
http://www.ev-power.eu/docs/bin/Setup123BMS_v1.2.0.zip

03.12.2012
 
BMS123 - BMS Main Controller

BMS123 - BMS Main Controller

The photos of the BMS123 Main Controller and the Current Sensor.

http://www.ev-power.eu/BMS123-System/

29.11.2012
 
BMS123 - Installation progress

BMS123 - Installation progress

Rough wiring of the BMS for testing purposes

25.11.2012
 
Installation of the BMS123 modules

Installation of the BMS123 modules

See detailed photo of the installation of the BMS123 cell balancing modules.

20.11.2012
 
Akumon -  check the function (if delivered in 2012)

Akumon -  check the function (if delivered in 2012)

Some of our partners have reported that Akumons from last shipments in 2012 were not working properly. We kindly ask all customers to check the Akumon function. In some cases the Akumon may discharge the battery continually until the battery is fully depleted. If you need any help, please contact our technical department. We will gladly offer a solution for you.

06.11.2012
 
mFi to monitor your energy demands

mFi to monitor your energy demands

The mFi sensors can help you monitor your energy consumption on-line from any location in the worlds over the mFi cloud services.

06.11.2012
 
Installing UBNT mFi sensors for GridFree application

Installing UBNT mFi sensors for GridFree application

Installing two mFi current sensors to measure the AC currents in a GridFree installation. More details to come soon…

03.11.2012
 
LAN Controller New Functions and Features

LAN Controller New Functions and Features

Check the update document for the LAN Controller describing new firmware with more features and options. Download the PDF here.

LAN Controller at EV-POWER.EU

01.11.2012
 
The BMS 123 CBU modules mounted

The BMS 123 CBU modules mounted

We are installing the demo instalation for the BMS 123 system to demonstrate the function for the GridFree energy storage solutions. Keep checking our blog for more details coming.

07.10.2012
 
FAQ: RT-BMS power-on and settings after STAND-BY

FAQ: RT-BMS power-on and settings after STAND-BY

Question: At the general power on (+12V) all the contactors are connected for short time. Is it a normal operation?

Answer: Yes, this is a safety checkup of all contactors and signal lights. This is to confirm that all of these outputs are working properly.

This logic is the same in your car:  when you turn on the starting key in your car,  all important signal lights on the dash board will light briefly to confirm that the signalization is OK (like airbags, EPS, motor oil and other lights)

Question: After the power-on, the unit performs a sort of scan of the system. The numbers of 01.00 to 01.63 (02.00 to 02.63, and 03.00 to 03.63) was displayed. This behavior is also present if we set a number of 4 cells on the system. Is it a normal behavior?

Answer: Yes, this is normal. After power-on the Master unit scans all possible combination (3x 64) to locate any CBU on the data line bus. This is for safety reason to confirm that the communication with all CBU is regular. Also it can help to locate any CBU that would be miss-addressed.

   ...more >>

16.09.2012
 
The initial testing of the mFi technology by UBNT

The initial testing of the mFi technology by UBNT

The mFi is an easy machine to machine communication solution combining the proprietary mFi protocol with the LAN (IP network) access to the devices.

12.09.2012
 
Plug-in Hybrid Refuse Collection Vehicle

Plug-in Hybrid Refuse Collection Vehicle

GWL/Power has supplied LiFePO4 Cells and the complete RT-BMS system to be used in France by SEMAT Company - ZOELLER Group, for their Plug-in Hybrid RCV (Refuse Collection Vehicle) with the Electrical Zoeller Lifter “E-Rotary”, on the PREMIUM “HYBRIS TECH” Chassis made by RENAULT TRUCKS. This hybrid RCV was presented at the “IAA” HANOVER 2012.

02.07.2012
 
FAQ: SBM questions

It is possible to change the voltage levels (thresholds) for the SBM settings?

  • No, it is not possible. The SBM boards are sold as they are. There is no way for users to change the voltage level settings. (For large quantity orders - 100 pcs and more - it may be possible to design a custom setting version of the SBM boards.)

Is it possible to use the SBM for 12 cells with less cells (e.g. only 8 cells or 9 cells)?

  • No, it is not possible. The board must be used with the exact number of cells. All cells must be connected; otherwise the board does not work properly. (For large quantity orders - 100 pcs and more - it may be possible to design a SBM with a customer number of cells.)

After deep discharge, how to restore the function of the battery pack?

  • First of all the SBM should be used only as a „last resort“ protection measure. This means you should monitor the battery pack and stop discharging before the voltage goes too much down. The SBM should not be used to replace such monitoring. 
  • Secondly, if the pack gets discharged deeply and the SBM makes the protection, we suggest recharging the battery pack as soon as possible.
  •    ...more >>

21.06.2012
 
LAN controller with the relay – your second brain

LAN controller with the relay – your second brain

The LAN controller is a very smart device that can help you to manage a lot of equipment based on the detection of measured values and a time schedule. It is possible to connect a variety of detectors or signal sensors.

The current status of the inputs can be monitored on-line over Internet using the web server. The settings of the LAN controller are made remotely over web page as well.  The status data can be also reported using the SNMP protocol. This allows to process statistics, get the history of events, etc.

In addition the LAN controller allows sending data using plain email. This means you can get the information to any PC or pocket device (e.g. smart-phone) without the need to check the web page.

   ...more >>

16.04.2012
 
Cell Ballancing Module (CBM) - example of installation

Cell Ballancing Module (CBM) - example of installation

An examples of CBM installation. The cable hooks are soldered on to the PCB directly.

14.04.2012
 
RT-BMS Connection to the TC Chargers

RT-BMS Connection to the TC Chargers

The diagram shows the interconnection of the TC chargers and RT-BMS Master control unit. Color of wires and codes is shown in the table below on the diagram.

11.04.2012
 
RT-BMS Monitor Screen Demonstration

RT-BMS Monitor Screen Demonstration

   ...more >>

11.04.2012
 
RT-BMS Monitor unit released - product and manual information

RT-BMS Monitor unit released - product and manual information

RT-BMS data monitor unit with a touch display (for RT-BMS Master unit).  Designed to read and display data from all software versions of RT-BMS Master unit starting from HW version 2.0. The BMS Master Unit is connected to the board using a special I2C to RS232 cable.

In addition to the display of the data, the monitor can be configured to save gathered data from the BMS to a CSV file to be downloaded to your PC.

Check the RT-BMS Monitor documentation on-line.

 

10.04.2012
 
CellLog 8S - latest firmware - V208 - download

CellLog 8S - latest firmware - V208 - download

Please download the latest firware for the CellLog 8S - version 2.08 - CellLog(8S)_V208.bin

02.04.2012
 
Check these FAQ published on our blog to understand the initial battery charging

Check these FAQ published on our blog to understand the initial battery charging

We remind all users of the LFP cells and LP batteries that the cells and batteries MUST be charged to full voltage level BEFORE assembling into a pack and before starting to be used.  source

The new 3.2V LFP cells delivered from the warehouse are partially charged. However before the first use, it is essential to charge each cell to full capacity. source

The cells must be charged individually to full voltage level (typically 4.0V) before assembling the battery pack. This way the cells will be fully charged and balanced before the first use of the battery pack and there will be no need to balance the cells using the BMS with balancing. source

   ...more >>

25.03.2012
 
A bug report for CellLog8

The CellLog8s has a bug in the firmware.  I’ve contacted the OEM via a radio-controlled model forum and he provided me with an updated firmware (v2.08).  The problem with the original firmware was that the alarm output from the cell / pack alarms did not trigger reliably when beyond the set points.

The CellLog8s also has a hardware bug in it that causes a cell load imbalance when used with more than 6 cells.  As delivered from the factory, it draws power from only cells 1-6 for the CPU and display.  So cells 7 and 8 would gradually go out of balance with cells 1-6.  The makers posted a picture of a hardware modification (adding a wire jumper) that cures this so that all 8 cells are drained equally. Unfortunately, it then does not work with 2 cells only after the mod (but I’m always going to be monitoring 8 cells so that’s ok).  They also posted an optional modification to replace one SMD resistor to reduce power consumption when using more than 6 cells. I’ve made both of these modifications.

http://www.rcgroups.com/forums/showpost.php?p=13452879&postcount=143

   ...more >>

25.03.2012
 
Using LiFePo4 for off-grid solar application with CellLog8 monitoring

Using LiFePo4 for off-grid solar application with CellLog8 monitoring

Check the “Solar Power - A Bodger’s Guide” blog to see the application of the LFP cells for solar applications. 

25.03.2012
 
CellLog8 video of functions

CellLog8 video

A Youtube video showing the CellLog8 functions and button operation.

26.01.2012
 
CAN Bus equipment operation

 

CAN Bus equipment operation

Question: I have a BMS with CAN option. I have a battery charger with CAN connector, I also have a dash board (display unit) with CAN option.  How can I make these components work together over the CAN bus?

Answer: In most cases you need a master CAN bus unit to make the equipment work together. Most of the CAN bus equipment is only either sending data (Read Only mode) or receiving commands (Write Only mode). This equipment has no additional logic to make decisions of operation for other equipment or to control it. The logic of the operation must be set by the master CAN bus unit.

Example:  BMS system is sending data (about the status of the battery pack). A ventilator with CAN input is only receiving data (turn on/off and the rotation speed). The BMS itself cannot manage the ventilator. There must be the CAN BUS master unit to process the data from the BMS over CAN and to decide if the temperature is over the limit and when the ventilator is to begin the operation. Then the CAN bus master unit i will send data to the ventilator over the CAN bus.

22.12.2011
 
PowerLog Data Storage

PowerLog Data Storage

Description of  logging the data traffic to internal 16MB storage. PowerLog 6S enables to store data during operation of the internal memory.  Please see PDF description.

Note: This instruction supplements Detailed manual / EN /.

26.11.2011
 
FAQ: RT-BMS connection to chargers - the wiring of the pins

 

FAQ: RT-BMS connection to chargers - the wiring of the pins

Please note that there is not any standard of the pins used at the charges to communicate with the BMS.  As seen from the two photos, there may be completely different wiring on different chargers. (Even on the same type of chargers but from different production time).  You always need to check against the information on the sticker at the connector. (Note: if the sticker was lost or removed, there is no way to confirm the wiring.)

FAQ: What type is the connector used at the charger to connect to BMS?

There is usually the Phoenix or WAGO type connector. (Wago 231-104-031-000). Take note that this connector is not designed for frequent manipulations. We suggest you can use other type of connectors that are designed for long life-time.

26.11.2011
 
The PCM circuit of the LFP batteries cannot replace proper fusing

The PCM circuit of the LFP batteries cannot replace proper fusing

Recently there were several cases of customers who damaged the LFP batteries with the PCM by over current or short-circuit.  As any batteries, the batteries with the PCM protective board need to be fused by a proper size fuse. In case of an accidental short-circuit connection, the fuse will protect the battery against high current that can cause the damage the PCM board and the whole battery.

The photo shows one instance of improper use of the LFP battery with the PCM. The two places on the battery connector plus pole prove the repeated over-current that even melted the connector.

The damage by over-current is not covered by manufacture warranty and there is no way to repair a battery that was damaged this way.

27.10.2011
 
Simple Battery Management Board (SBM)

Simple Battery Management Board (SBM)

The easiest way to protect a lithium battery pack. The SBM board manages a pack of cells and disconnects the load under any unfavourable circumstances: cell over voltage, cell undervoltage.

SBM16/60 - the management board for 16 LFP cells (48V) with power up to 60A. (photo)  Check the PDF with technical specifications for SBM16/60. For higher loads you need to use a DC contactor to be managed by the SBM board. This drawing shows the DC contactor installation.

08.08.2011
 
FAQ: How to connect the signal outputs of multiple Akumons

Answer: The Low Voltage Output (VYBITO / VYB) and the Over Voltage Output  (>17V) are galvanic separated outputs. This means it is possible to connect these outputs in parallel to get the signalization. The parallel connection works as „one of any“: this means if one of the Akumon signals the hazardous status, the data line will be connected.

NOTE – WARING:  Never connect the Balancing Output (EXT) of different AKUMONS together!  Since the balancing output is connected to the battery, you will make a short-circuit connection if you connect the EXT lines together! 

20.07.2011
 
FAQ:  Battery deeply discharged – what to do?

FAQ:  Battery deeply discharged – what to do?

By mistake I have deeply discharged the 12V LP battery.  When I discover this situation, the voltage of the battery is < 1.5 Volts. How can I restore the battery?

Honestly, there is no way to restore the LP/LFP cells and batteries if there were deeply discharged. (Bellow 2.5V per cell or 10V per 12V battery.) If the battery is deeply discharged the internal structure of the cells is damaged. There is no way to get the battery back. The battery must be replaced with another battery.

Trying to charge this kind of empty battery will only result in even bigger damage and the battery will swell and release the gases!  Never try to “correct” the problem by swift charging!

The only option is to disconnect the battery and wait for some time (hours/days) to see if the voltage returns back to the minimal level.  If the voltage returns by itself, there is still hope that such battery may be charged. However this charging must be done with very small currents (0.1C or less) and the charging must be monitored.  If the voltage does not return and stays low, the battery is dead.

19.07.2011
 
FAQ: “Sudden” battery discharge

FAQ: “Sudden” battery discharge

I have bought a several of LFP cells and made the pack with them to replace the lead-acid battery in my houseboat. The LFP battery was working great and it gives much more capacity than the lead acid. However after several weeks of usage, I came back after the weekend and I found out that the battery is completely discharged. Why this happen?

Please note that unlike the lead acid batteries, the LFP batteries will be completely damaged if you discharge them bellow the minimal voltage (usually >2.5V per cell, or bellow 10V for 12V battery). This may happen if you have some equipment that takes the power from the battery continually. Maybe you simply forget some light or some equipment „on“, and after few days the battery is deeply discharged and damaged forever.

The example:  12V 90AH battery is connected to houseboat with alarm. This alarm takes only 5W of power (12V 0.4A). If the battery has 70% charge, the alarm will discharge the battery in about 150 hours, that is 6 days. If you have some equipment with higher power consumption, the discharge will be much faster, even perhaps less than one day.

   ...more >>

10.07.2011
 
The application of the Cell Ballancing Module

The application of the Cell Ballancing Module

16 CBM units are used to balance the final stage of the charging of the EV scooter GWL/Scooty. The 16 lithium cells make the total of 48V (nominal voltage). Each cell using one CBM for balancing.

26.06.2011
 
You must charge before the first use!

You must charge before the first use!

We remind all users of the LFP cells and LP batteries that the cells and batteries MUST be charged to full voltage level BEFORE assembling into a pack and before starting to be used.

For the 3.2V cells, the full charge voltage level is 4.00V and the charging is the 12V LP batteries)

Even in simple installations, it is important to make the first charging. Example: when assembling a 48V pack using 4 pieces of 12V batteries, it is very important to charge all batteries to the same voltage (16V) before assembling the whole pack.  Only after the batteries have been balanced to the same voltage level, it is possible use them as a pack and to charge the whole pack together using the 48V charger.

Please remember:  FIRST CHARGE, THEN USE!

30.05.2011
 
Installing 6 Akumons to monitor up to 6 pcs of 12V LP packs

Installing 6 Akumons to monitor up to 6 pcs of 12V LP packs

This is a photo from our customer showing an installation of 6 pcs of Akumon management boards together with a service battery and relay. This installation is designed to monitor up to 6 pcs of 12V LP block batteries.

22.05.2011
 
The demonstration of function of the CBM boards

The demonstration of function of the CBM boards

The CBM boards (Cell Ballancing Module) will start balancing of the cell as soon as the full charge level is reached. The full charge level is is at 3.60V for LiFePO4 cells.

The diagram shows the charging of a 4-cell battery pack with following configuration:

Cell1 - no CBM board installed
Cell2 - one CBM board installed (balancing up to 1.7A)
Cell3 - two CBM boards installed (balancing up to 3.4A)
Cell4 - three CBM boards installed (balancing up to 5.1A)

The first part of the diagram shows the charging with 1A current. The Cell1 (with no CBM) goes over the 3.8V level and the voltage would increase very rapidly. Cells2, 3, 4 are ballanced with the CBM modules and the voltage is kept bellow 3.6V.

The second part of the diagram shows the charging with 3A current. The Cell1 (with no CBM) goes over the 4.4V level and is OVERCHARGED. The Cells 2 (with one CBM) is balanced and the voltage increases slowly. However ONE CBM (balancing up to 1.7A) is not enough for the 3A charging current. As a result the voltage would also increase above 3.8V, if not stopped. Only Cell3 and Cell4 (with 2 and 3 CBM boards) are ballanced sufficiantly and the voltage is kept bellow 3.6V.

   ...more >>

15.05.2011
 
The demonstration of battery overcharge

The demonstration of battery overcharge

The analysis of the RT-BMS data log supplied by customer:  Cells #3 and #6 were overcharged, as the voltage reached above 4.0V. These cells are already fully charged. It is necesarry to balance these cells untill the voltage level of all the cells in the battery pack reaches the same level.

Suggestion:  it is extremely important to balance all the cells to the same voltage level (4.0V) at the beginning of the usage of the battery pack.

04.05.2011
 
Cell Balancing Solved! - The CBM1 module is here

Cell Balancing Solved! - The CBM1 module is here

GWL/Power is introducing the easiest solution to keep your LiFePO4 cells balanced. The CBM module provides the cell balancing whenever the voltage increases over the 3.60V cell balance detection voltage.

Product specifications
Cell Balancing Module to limit the overcharge of single LiFePO4 cell (3.2V)
Balancing detection voltage: 3.60 V (+/- 0.05V)
Balancing release voltage: 3.50 V (+/- 0.05V)
Maximal voltage: <5 V
Balacing current: 0 ~ 1.7 A
Self consumption: < 20 microA
Working temperature: -40 to +125 deg. C
Temperature of resistors: up to 85 deg. C
Dimensions: 55 x 55 x 8 mm

Cell Balancing Module (3.60V- 1.7A) product information

08.04.2011
 
RT-BMS CBU module V4.0 dimensions

RT-BMS CBU module V4.0 dimensions

Check the CBU module dimensions.

07.04.2011
 
Solar charging of the LFP(LYP) batteries

Solar charging of the LFP(LYP) batteries

The high powel solar panels are used to harvest the solar evergy into the LFP batteries. A specialized solar charger manages the charging of the battery pack. The solar charging allows to be full independant (off the grid).

14.03.2011
 
Cooling Akumons using computer fans

Cooling Akumons using computer fans

(source Fiat Seicento project)

14.03.2011
 
High speed balancing with high currents using Akumons

High speed balancing with high currents using Akumons

A simple solution using the automotive 12V relay and the 12V halogen bulbs. 

01.03.2011
 
Testing of the 36V 20AH battery pack with SBM

Testing of the 36V 20AH battery pack with SBM

(SBM - Simple Battery Management)

01.03.2011
 
The detail of the Simple Battery Management (SBM) Board

The detail of the Simple Battery Management (SBM) Board

23.02.2011
 
RT-BMS CAN Bus definition

RT-BMS CAN Bus definition

Following datagrams are sent by the RT-BMS master over the CAN bus at speed of 250 kb/s. The CAN module uses the version 2.0 of the protocol.

Address : 0x14A10101

D0 : Battery pack total capacity (0 .. 100 %)
D1 : Current  (-127 … +126, value * 5 = current [A])
D2 : Total voltage (low byte)
D3 : Total voltage (high byte)  - range 0 … 65535, value / 10 = voltage [V]
D4 : Highest temperature on the cells (-127 … +126 deg. C.)
D5 : Bit 0 - reading, Bit 1 - waiting, Bit 2 - balanicing , Bit 3 - running, Bit 4 - low voltage, Bit 5 - error (not serious), Bit 6 - error (serious)
D6 : The address of the CBU causing last error.
D7 : Internal error code (only for service purposes)

Address : 0x14A10102

D0 : Lowest voltage of the cell (low byte)
D1 : Lowest voltage of the cell (high byte) - range 0-65535, value / 100 = voltage [V]
D2 : The address of the cell with the lowest voltage
D3 : Highest voltage of the cell (low byte)
D4 : Highest voltage of the cell (high byte) - range 0-65535, value / 100 = voltage [V]
D5 : The address of the cell with the highest voltage
D6 : Lowest temperature on the cells (-127 … +126 deg. C.)
D7 : Reserved

   ...more >>

07.02.2011
 
Testing the 20AH cells 

 

Testing the 20AH cells  (from our customer)

Please notice the circuit-braker attached to the pack. 

01.02.2011
 
FAQ: The proper installation the key to success for the BMS function

 

FAQ: The proper installation the key to success for the BMS function

Over the past two years of supporting the customers with the RT-BMS (and other management solutions), we have learned the most frequent installation faults that can cause the BMS system not to be working properly.

Please note, that one  „missing CBU“ can lead to a damage of the whole battery pack, if operated for a long time without inspection.

The frequent installation faults:

  • Improper cabling of the 10 pin flat cable – the result: some of the CBUs are not find during the boot-up of the whole system.  Solution:  check the flat cable and/or replace the cable if needed
  • Humidity, water drops, and wetness on the CBU boards – the result: oxidation of the CBUs, malfunction of the CBUs. Solution:  the CBUs must be protected against moisture and water.  Please change the installation to allow such a protection.
  •    ...more >>

01.02.2011
 
The Float voltage for the LiFeYPO4 batteries

 

The Float voltage for the LiFeYPO4 batteries

Unlike the lead acid batteries, there is no need for lithium batteries to apply the constant voltage to maintain the cells in a fully charged condition. (Typical for lead acid batteries 12V -  Gel 13.05V, Flooded 13.4V and AGM 13.6V values @ 25°C). 

In case you replace the lead acid battery with the LiFeYPO4 battery, it is good to check how the device behaves when charging the battery.  When applying the unmanaged float voltage (all called trickle charge), the voltage for LP 12V battery should be always bellow 14.4V  (3.60V x 4 cells).  Simply said the AGM value of 13.6V should be always OK with the LP batteries / LFP cells.

20.12.2009
 
Dynamic-BMS for 12 Volt Lithium Yttrium Iron Batteries

Dynamic-BMS for 12 Volt Lithium Yttrium Iron Batteries

Please see another photo of our D-BMS system for 12V batteries. Get more details here: http://gwl-power.tumblr.com/tagged/D-BMS

15.11.2009
 
Real Time Battery Management System (RT-BMS)

Real Time Battery Management System (RT-BMS)

The Real Time Battery Management System (RT-BMS) is an advanced battery management solution for any type of lithium-based cells.  Unlike other management systems, the RT-BMS provides the battery management during the complete charge and discharge cycle. Each cell is managed individually and the master control unit manages the whole chain of cells.

The whole RT-BMS system is compatible with all current types of traction cells (Pb, A123, LiPol, LiFe, LiFePO4, LiFeYPO4, etc.) – i.e. all types of rechargeable cells with an operating voltage between 2.7V and 5.0 Volts.

Please download Real Time Battery Management System (RT-BMS) Product Development Report 2009/11/15

08.11.2009
 
Battery Monitor and Recorder Technical Specification

Battery Monitor and Recorder Technical Specification

Please see the technical specification of the CellLog monitor.

ONLY EUR 27.00 !!! Please contact us for express delivery in Europe.

08.11.2009
 
Battery Monitor and Recorder Connection Diagram

Battery Monitor and Recorder Connection Diagram

To measure a single pack (a single battery), the voltage must be at least 4V. Please connect inbetween PINS (-) and (1).

08.11.2009
 
Battery Monitor and Recorder in Real Use 

 

Battery Monitor and Recorder in Real Use 

  • CellLog 8S has been 100% calibrated before it enters to the market, at the same time, it supports the calibration by users themselves.
  • CellLog 8S has a 16Mbit flash storage, which can log offline data in 36 hours.
  • Support upgrading the hardware program by USB port. The CellLog 8S also supports the “logview” software and can display, plot and analyze the charge and discharge data by it. (See detail information about logview in the following website: http://www.logview.info)

ONLY EUR 27.00 !!! Please contact us for express delivery in Europe.

ENGLISH MANUAL DOWNLOAD

08.11.2009
 
Battery Voltage Monitor, Logger and Recorger

 

Battery Voltage Monitor, Logger and Recorger

  • Small size with multiple functions, backlight 128*64 lattices LCD and Buzzer Tone Reminder; the interface can be operated smoothly.
  • It can not only measure 2-8S Li battery individual voltage, but also measure NiMH, NiCd, Pb battery pack voltage.
  • It can be set Individual Voltage Alarm and Pack Voltage Alarm, Overvoltage Alarm, Low Voltage Alarm, Differential Voltage Alarm and Time Over Alarm. What’s more, the extra alarm output can be linkage controlled by the users.
  • It has 8 sets default monitor alarm settings, which can be selected for different battery packs.

 

ONLY EUR 27.00 !!! Please contact us for express delivery in Europe.

01.11.2009
 
Dynamic-BMS for 12 Volt Lithium Yttrium Iron Batteries

 

Dynamic-BMS for 12 Volt Lithium Yttrium Iron Batteries

The Dynamic Battery Monitor System (BMS) with balancing function is the first worldwide solution to manage series of 12V Lithium Yttrium Iron batteries (LFYP batteries).  The LFYP batteries made by Thunder-Sky are the only direct 12V lithium solution on the world market.  Now you can use 12V lithium batteries instead of many small 3.2V cells.  Read more in Product Development Report 2009/11/01

28.10.2009
 
36V pack assembled

 

The 36V pack assembled and the Simple Battery Management (SBM) installed. Now we are ready to go!


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