I got my hands on a Tangent 6KW kit, much thanks to Dave!
I was initially going to use Lipo 14s2P by way of 4S+4S+6S x 2 for a total of 20Ah. All is great but esthetically it will not be great on the bike, also a slightly less favor given the the price availability compared to alternative 20700 cells for me.
I started to consider building a custom pack using Sanyo NCR20700B cells rated for 15A max continuous 4000mAh. My pack would need 14S and I would need 8P so that I'm not stressing the battery, it might see max 120A burst which should be good since they are rated at that for continuous operation.
My challenges and uncertainties include:
1) I want to go BMS less for simplicity and take care of the balancing with balance leads during charging, similar to hobby lipos, is this reasonable/acceptable practice?
2) I would like to connect the 20700 cells 14s only. No welded parallel connections. I would use some XT's or bullets. Any problems with this approach?
3) The series welded connections would likely need to be copper 0.7mm2 minimum for safety given the current capability of the cells https://endless-sphere.com/forums/viewtopic.php?f=14&t=68005 but From what I understand the hobby type welders like these typically don't handle copper all too well?.... True/False? I'm not sure because it says it should handle it but I've read other threads where copper welding is supposedly more difficult http://www.ebay.com/itm/Canada-2-in...357227?hash=item3f7f1a1c2b:g:3UsAAOSw~rpZP7qf
I was initially going to use Lipo 14s2P by way of 4S+4S+6S x 2 for a total of 20Ah. All is great but esthetically it will not be great on the bike, also a slightly less favor given the the price availability compared to alternative 20700 cells for me.
I started to consider building a custom pack using Sanyo NCR20700B cells rated for 15A max continuous 4000mAh. My pack would need 14S and I would need 8P so that I'm not stressing the battery, it might see max 120A burst which should be good since they are rated at that for continuous operation.
My challenges and uncertainties include:
1) I want to go BMS less for simplicity and take care of the balancing with balance leads during charging, similar to hobby lipos, is this reasonable/acceptable practice?
2) I would like to connect the 20700 cells 14s only. No welded parallel connections. I would use some XT's or bullets. Any problems with this approach?
3) The series welded connections would likely need to be copper 0.7mm2 minimum for safety given the current capability of the cells https://endless-sphere.com/forums/viewtopic.php?f=14&t=68005 but From what I understand the hobby type welders like these typically don't handle copper all too well?.... True/False? I'm not sure because it says it should handle it but I've read other threads where copper welding is supposedly more difficult http://www.ebay.com/itm/Canada-2-in...357227?hash=item3f7f1a1c2b:g:3UsAAOSw~rpZP7qf