blog -> Tests and diagnosis

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


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20.01.2019
 
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.

   ...more >>

19.12.2017
 
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!

09.11.2017
 
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 32 cells of LFP or 40 cells of the LTO technology

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. 

03.11.2017
 
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.

   ...more >>

16.10.2017
 
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.

   ...more >>

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 >>

25.11.2015
 
BMS2405 for LTO cells applications

 

BMS2405 for LTO cells applications

We keep testing the BMS2405 for the LTO cell applications. With 2.4 nominal voltage, the 24V storage packs use 10 cells. 

13.09.2015
 
The exhibition of the battery products at GWL

 

The exhibition of the battery products at GWL

When coming to GWL warehouse and office in Prague, you can visit the exhibition of the battery products and samples.  In addition to the cells, we show various examples of battery solutions, including the BMS, solar panels, chargers, MPPT regulators and others. 

We always welcome your visit and suggest you fix an appointment for a visit so that we are ready to welcome you and spend quality time with you.

07.06.2015
 
More and more testing of the LTO technology

 

More and more testing of the LTO technology

The graphs show the test results of the 40AH LTO cells. 

We keep testing the latest models of the LTO cell technology. Customers who request samples can contact us for details of the co-operation.

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