Am I misreading those batteries or do you have them in Parallel and series as one large 31 amp hour 7.4V battery?
Yep, it's 2-series, 15-parallel for 7.4V nominal and 33ah (15 cells X 2.2ah). This will be added to the other 18-series 15-parallel cells I've been using for about four months now on the bike.
Xyster, on the side of the battery pack where the cells are jumpered to put them in series, the wires running parallel, will theoretically carry no current, and are therefore unnecessary, at least from a power standpoint.
1) do you mean vertical parallel or horizontal parallel
? I'm not clear on of which wires you speak.
2) can you explain why these wires would not carry current? That's a shocker to me! This configuration works in other parts of the pack. But 35 amps is the max I can make this pack draw, most of the time it's around 33-34 amps. Those wires making the S curves are the wires that jumper the two packs together in series, and also connect to the charger. They are 18 gauge. The wires running straight are 12 gauge. Both ultra-flexibility silver spaghetti wire coated in silicon -- solder sticks much better to this wire I've found and it's a real joy to work with in comparison to copper.
After much research at rcgroups.com I learned I probably damaged some cells during the overdischarge event such that they've retained capacity, put lost some current capability permanently. I figured that was the reason for the ~1C max current I'm seeing. Patrick M has the same cells in a 12s8p config and reports 1.8C max.
it might be a good safety feature if the individual series strings each had their own fuseable link to protect against a single cell shorting.
I'm recall Aerowhatt having hundreds of little fuses built for his hybrid SLA/18650 pack. Problem with both fuses and wires:
1) The pack is basically done and until hell freezes over I'm not going to again desolder and resolder it!
2) Space. Where would you put this calculated length of wire?
3) What's the likelihood of an apparently good cell shorting closed circuit while operating within spec? The only cells I've blown up (so far) were via overdischarge from my own ignorance.
Thanks guys for the feedback and suggestions!