Blog - Tests and diagnosis

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

16.04.2019
 
GWL Battery Abuse Test Station – Sneak peek

GWL Battery Abuse Test Station – Sneak peek
GWL/Power team is carrying out the LFP cell abuse tests. We have constructed the Battery Abuse Test Station that consists of following main parts: 1) Equipment table – the measuring equipment is installed here 2) Mechanical abuse location – a block of concrete to be used as a placing area to perform the mechanical abuse 3) Fire chamber – the test chamber for short circuit, overcharge other tests 4) Exhaust fumes piping – the fumes circulate in the pipes until the sediments from the fumes settle down in the horizontal pipe – they are used to analyze the health risks associated with the abuse tests If you wish to know the results of our tests, follow us here or on our , or pages where the results will be published soon...
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16.03.2019
 
Raspberry Pi BMS communication module

Raspberry Pi BMS communication module
Do you need to know how much capacity remains in your battery? Stay tuned - during Q3/2019 we will announce a communication module based on Raspberry Pi project. Together with our CPM1 board, it will bring you information about SoC and DoD of any battery pack from 4 to 16 LiFePO4 cells. It will allow reading this information via touch screen or TCP/IP (ethernet). On the photo, you can see LCD display connected to the popular Arduino platform. However, after the first quick tests, we found out that better performance will ensure a Raspberry Pi platform. Our team will work hard and publish some updates soon.

04.03.2019
 
Winston cells passed the China Army military safety tests

Winston cells passed the China Army military safety tests
The photo shows the punch-through simulating a shooting from 45 mm calibre anti-tank gun. Fully charged cells are punched through simulating the shoot-through from a military weapon. The purpose of the test is to see the safety and stability of the lithium cells. As visible from the photo, the cells remained complete, did not burn, did not set on fire and did not explode. This kind of extreme abuse proved that superiority of the Winston Battery lithium cells. These cells are suitable for all kinds of applications including the heavy duty and military grade installations.

28.02.2019
 
What is the Peukert’s Exponent for LiFePO4 cells?

What is the Peukert’s Exponent for LiFePO4 cells?
The is used for the lead-acid batteries. Simply said this exponent is the ratio between the charging and discharging of a battery. It means how much energy you need to charge compared to the energy you get when discharging. For the LiFePO4 cells, the efficiency of the charge and discharge rate is very high – above 97% and more. That is why the Peukert’s Exponent is close to 1.00. The battery producers do not give this value because it is not necessary for the LiFePO4 cells. You can find that consider using the value between 1.01 to 1.03 for different models of the LiFePO4 cells. If you need additional support, don't hesitate to ask the for help. We will always try to find the best solution for you.
Peukert’s Exponent
some discussions on the internet
GWL/Power team
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20.01.2019
 
How to calculate the cost of stored energy in a LiFePO4 cell?

How to calculate the cost of stored energy in a LiFePO4 cell?
Lead Acid or LiFePO4? This is the price per kWh stored and cycle life comparison. The two following graphs will show you the comparison between the Lead Acid and LiFePO4 batteries. The first one compares the average number of cycles (cycle life) according to the battery type and a depth of discharge. The second graph applies these figures to calculate the cost for one kWh of energy stored – again according to the battery type and the depth of discharge. If you wonder how we got these figures or even would like to calculate the costs for a kWh stored for your own battery storage system, follow the steps below the graphs. How did we get these numbers? Plus some basic terms definitions > A 300Ah battery costs around 330€ > It has a voltage of 3.2V. The battery capacity in kWh is then:3.2 * 300 = 960 Wh = 0.96 kWh ~ 1 kWh > Because we want to gain the longest possible battery durability, we will use it only for 50% of the capacity (this is so-called 50% DoD – depth of discharge). The usable battery capacity is therefore 0.5 kWh.
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19.12.2017
 
Three million AH - Sinopoly Test Data and Project Reference

Three million AH - Sinopoly Test Data and Project Reference
Check the update for the Sinopoly Test Data for the test of the 200AH cell. See the project reference using the Sinopoly battery products. See more here at special page:
Celebrate with us - over 3 milion Ah sold in the Sinopoly cells!
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09.11.2017
 
Determining the number of cells for a battery pack

Determining the number of cells for a battery pack
Question: I need a 100V DC pack. How many cells do I need (for LFP or for LTO)? Answer: The above table shows the various configurations of the number of the cells and the voltage levels that will be reached with the configuration. For a 100V pack, the typical installation will be based on serial connection of or .
32 cells of LFP
40 cells of the LTO technology
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07.11.2017
 
LTO cell test results

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.

03.11.2017
 
Internal resistence

Internal resistence
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.
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16.10.2017
 
The temperature of the LFP cells

The temperature of the LFP 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. The cells can be stored and operated within these temperature limits. However the performance of the cells is dependent on the temperature so the performance of the battery differs in various temperatures. In simple words, when the cell is cold (bellow zero) the performance is limited, when the cell is hot (above 40 °C) the drain of the cell must be limited as well in order to protect against overheating.
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