Building a LiFePO4 battery pack?

HI all,

Member LEDAdd1ct recently contacted me about building a light from a magcharger, and would like to use 3 lifePo4 32650s as the power source.

What I need to know is mostly about assembly of the pack. First off, the 32650 cells dont come with the option of tabs. I was thinking this was a mandate with lithium cells for pack making correct? Or is soldering ok?

Second we need to protect each cell because they will be charged in series. Here is the only protection circuit I have found that will fit.

Google "Protection Circuit Module (PCB) for 4S LiFePO4 Battery Pack (5/12A)" Is the 3rd link down from all battery.

Will this work with only 3 cells?

Thanks all
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Not sure about your size limitations but here's a bunch of multi-cell PCB's

ww.batteryspace.com/pcmforlifepo4batterypacks.aspx

Way back when, I soldered leads to some A123 cells with no issues. Just the usual recommendations to use a hot iron, some additional flux, tin both pieces and do the actual soldering very quickly.

I researched all the available printed circuit boards on batteryspace.com and eliminated all of them because they were either too large or required minimum quantity of 100 pieces. The PCB VOB suggests is literally the only one I could find that will physically fit in a Mag Charger and which is readily available.

The reason we believe it will work for three cells even though it is nominally described as being for four cells is because the literature on the sales page indicates connection points for a three series pack at 9.6v. I just called All-Battery's customer service line for additional clarification. I will post back here after hearing from them.

In the Megarays' OEM LiFeP04 packs, they utilized a 7S PCB but used only a 6S pack. Just an FYI that there were no alternate markings on the PCB but they just wired up pads 1-7 instead of 1-8. So hopefully yours will work the same.

Here is a direct link to the PDF:

Link