Blog - LiFePO4

How to replace Li-Po cells KOKAM by LiFePO4 cells?

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Generally said LiFePO4 Cells and batteries are very suitable for similar traction application and can meet all requirements that customer need. If connected in parallel, they can also meet capacity requirement.

The most suitable cells are Wina 100Ah cells: http://www.ev-power.eu/_d2900.html

Wina cells offers high power density - they are little bit smaller having same capacity as other LiFePo4 cells. They also provide wonderful discharge capabilities - very high currents with minimum voltage sag. These cells can meet requirements of high charge and discharge currents, versatile temperature operation range, much longer life then Kokam cells (minimum 2 to 3 times more) and other advantages.

However, it is necessary to solve some technical differences:

• Dimensions  - question: what space is available for battery? Kokam battery cells have a different size than the suggested WINA LiFePO4 cells.
• Nominal Voltage - LiFePo4 technology dispose of slightly different voltage then Li-Po cells. Nominal voltage is 3.2V instead of 3.7V. Important to check the voltage requirement of the motor controller and other equipment.
• battery protection, BMS - Is necessary to use this type of BMS, which can be adjusted to the appropriate values ​​as specified LiFePO4 technology. We recommend use professional monitoring system BMS123-OFFGRID. More information and possibilities of the BMS123: http://gwl-power.tumblr.com/tagged/BMS123

For obtaining nominal voltage of 48V is needed 16 pieces of LiFePO4 battery cells connected in series. (voltage of one cell is calculated 3V)

To get the total capacity of 200Ah is necessary to connect 2 cells in parallel. These 16 pcs of parallel blocks then connect in series.

Please check PDF with detailed specification of Wina 100 Ah cells here: http://files.i4wifi.cz/inc/_doc/attach/StoItem/2900/GWL-WINA_WN100AH_Specifications.pdf

LiFePO4 technology is ideal solution for electric boats, cars and other EV application is safety and there is long lifetime and thousands charging cycles.

Needed Products:

16x WINA 100Ah LiFePO4 cells

1x BMS123 OFFGRID - Main Controller

1x BMS123 - Cell Module IN

1x BMS123 - Cell Module OUT

2x BMS123 - Cell Module

1x BMS123 - Current Sensor 400 Amp

1x BMS123 - CURRENT meter

1x BMS123 - FUEL meter

8x Terminal cover - black

8x Terminal cover - red

Other information:

• For connecting battery cells WINA is appropriate to use flexible terminal connectors. Please see overview of the Cell Terminal Connectors and the Compatibility Guide
• For connecting battery pack with other electrical equipment is appropriate to use Copper Cable with shielding RADOX 35 mm Shielded HS84100296
• Practical information about similar projects:  http://gwl-power.tumblr.com/tagged/Boat