14s7p Panasonic PF build - current sharing advice

Batteries, Chargers, and Battery Management Systems.
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mrzed   100 W

100 W
Posts: 239
Joined: Feb 06 2009 6:48pm
Location: Victoria Canada

14s7p Panasonic PF build - current sharing advice

Post by mrzed » Sep 12 2016 5:21pm

I'm about to start on my third battery build. First was a recycled toolpack cells from Makita packs long ago that I put together for my lawnmower. I learned there that even if it was OK to solder cells, I'm nowhere near good enough at soldering to make it OK for me. I also learned I don't have the time and patience for sorting cells. Second was a 10s/3p arrangement for a very lightweight geared motor build. That one is still running - but appears to be having problems delivering hte amps. I have to pull it apart to see where it/I went wrong. I'm only using a 15 amp controller on this, so the cells should be more than up to the task even with only 3p (another topic).

The new build will be for a frame pack in a custom enclosure. The equipment is:
- 100 PF cells sourced from Tumich - currently sitting at resting voltage and in 10-cell holders that I will be re-using
- JP spot welder - used for the 10s3p pack and confirmed good
- a roll of .015 8mm nickel strip
- Cheap soldering station and poor to middling soldering skills
- paper insulators for the positive end

The cells will stay in the 10-cell groups, so that I can use the holders for structure. The layout is pictured, but I don't have the connections decided yet - dark lines indicate the 10-cell holders - so I have to stick with the overall layout to fit the triangle space. I figure I'll just use a single layer of the nickel for the parallel groups - so I'm mostly looking for advice on the series connections. Plan is to use with up to a 40 amp controller. I figure that will be barely over 2C.
Battery14s7p.JPG (50.62 KiB) Viewed 256 times
For the 10s3p build - I soldered the balance wires onto the strip before spot welding to reduce heating. I thought I would do the same, but I'm considering using silicon wire soldered to the strip before welding for the series connections as well. Other option could be doubling up to two layers of strips for series to increase current capacity.

Any advice welcome. Thanks

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