EVBike Battery Cell Balancing
Inside the EVBike battery: the graph shows the results of EVBike battery balancing - with CellLog 8 used for monitoring. As seen from the graph, the cells are balanced to the same voltage level at the end of the charge.
WINA 10AH LiFePO4 cell - high current peak discharge
The test results of the high current peak discharge of 5C and 7C for WINA 10AH cells.
Check the WINA LiFePO4 cells http://www.ev-power.eu/WINA-30Ah-100Ah/
The brand name Samsung Li-ON cells have very poor life-cycle performance.
Please see the information from the official Samsung datasheet. This information shows that the life span for the ICR 18650-26A model is only 300 cycles! After 300 cycles the capacity will drop to 70%. What a contrast with the LiFePO4 cells that have 2000, 3000, 4000 or even 8000 full cycles.
We suggest avoiding the usage of such Li-ON cells for any serious applications.
Please think about this: if the TOP manufacturer Samsung gives „confidential“ information with such a low cycle life span, how much lower will be the life span of the identical cells produced by some no-name Chinese manufacturers? Well we even do not wish to try to guess what the reality may be.
Is there a difference between 100AH and 100AH?
The test data prove quite some difference in the performance of LiFePO4 cells from various manufactures. This test shows the difference between discharge results of GBS 100AH and WINA 100AH.
The discharge times at 1C (105Amp) from full charge to 12V are: 3000 seconds for GBS100AH, 3790 seconds for WINA100AH. The difference is 26%. When calculating the total energy, it is obvious the performance of the WINA100AH cell is 20% to 30% higher.
Which cell will you choose?
Cold temperature tests of SE100AHA and CA100AHA
The graphs show the test results of cold temperature discharge tests for the CALB SE100AHA and CA100AHA cells. The performance is compared with tests at 31*C (88F) versus cold temperature -18*C (0F) to -4*C (25F) (the cells keep warming-up as they are discharged).
The tests were made ba EVTV and the details are available here:
The original Winston LP12V80AH battery - after 3 years at 98AH!
The photo shows the LP12V 80AH battery produced by Winston (ThunderSky) in 2010. After 3 years of continueous use it gives 98 AH (!) of real capacity. After the warranty period, the battery was modified by the user to get access to each cell and to monitor the voltage of the cells, using the CellLog8.
What can be said? It seems better than “ideal dream”. But it is not a dream, it is the reality of the LFP technology. With LFP cells energy storage is possible!
LiFePO4 Cell Test Data - abuse and extreme conditions
The abuse test data show the results of hazardous situations and lithium cell extreme conditions: Overcharge by 1C and 2C current, overdischarge test by 0.5C current, cell damage – short Circuit, cell crush Test (50% of the cell), nail penetration test (3 mm), high temperature (150*C and 175*C), temperature performance, cycle life (0.5C).
Check the data at the PDF file.
These tests show that the LiFePO4 technology is really safe and can be used without worries about the danagers.
High Current Charging and Discharging Report for WINA Cells
The purpose of the test is to verify the performance of the LiFePO4 cells in high
current discharge and charge conditions:
1) What are the discharge characteristics for 1C to 3C currents?
2) How will the individual cells perform under these tests?
Download the test report here.
The Test Report: Comparison of the 36AH LiFePO4 pack with 12V/40AH SLA battery
The purpose of the test report is to show the specification of the LiFePO4 battery made of WN-36AH cells.
The advantages of the WN-36AH cells
- professionally produced LiFePO4 cells
- stability during high current discharge
- the discharge with long flat discharge area (3.30V to 3.10V)
- aluminum case for protecting the cell
- no overheating or heat release during operation
Download the full test-report here. Check the offer of the WINA cells at EV-POWER.EU
High current peak discharge of 40AH LFP cells
The graphs show the discharge of 40AH LFP cells with 100 Amp and 500 Amp currents. These high current tests prove that the performance of the cells is very identical and that there is no defect of these cells.
Checking the performance of cells after 2 years of usage in EVBike application with 100+% for most cells
Based on a customer request, we performed a cell performance verification for the capacity of the cells. Despite a heavy usage and some abuse instances, the capacity of majority of the cells was above 100% of the nominal capacity.
Example of discharge of 20Ah cells at 360A (18C)
The graph shows discharge characteristics of 12V batteries using 20Ah cells at 360A.