No it is not going to work like that, you need to connect - in the very right of the top row to plus of the lower block straight through! Think it through.
Follow the current flow and you find the mistake.
The plus P row at the bottom is orphaned, you need to arrange the cells in a way you have all “digital” 8 shaped strips at the bottom, alway 6 cells connected.
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How’s that?(above) Thanks for catching that, it’s 4am and I was winging it.
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I’m late to the party, but for context, 12s4p eve 40PL, full BMS (220A/400A), and charger is going to cost me $660 Canadian (all in) from a local builder. (That’s about $485 USD). He builds many batteries for the locals, including for efoil. He says the 12s3p seems to be the sweet spot for those who have built backpack foil assists, so that’s probably a good call. And the 12s3p is nice for power and keeping esc heat down (from what I’ve read in the forum). Curious how the cooling will be in the backpack. Water splashes on the aluminum box for cooling? Maybe passive air cooling is fine for your esc?
Context: I’m also just starting my build and considered building the battery pack myself, but didn’t have the confidence to do the cells myself. Lots of stuff online about safety of the builds, but I’m lucky I found this builder. He knows his stuff for cells, connectors, thermals, etc. Sounds like you have no one local though, even on Oahu :(. I opted for 12s4p with 75200 pro v2 vesc with 6384 motor. I over spec’d for the vesc and the larger battery pack to hopefully have no heating issues because I plan to efoil a bunch at the start and then progress to foil assist (hopefully) for downwinders. Haven’t been to Kauai yet, but love Oahu and Maui
It depends on the prop - how much esc heats
Brand new to this forum and to foiling. I literally just found this diy foil assist this morning and am solidly down the rabbit hole. I have most of a setup in carts but am wondering if you were successful with the greenworks batteries? They are easy to get and I have 2 with chargers already. I would be super excited if they worked out. Thanks
To be honest, I haven’t made much progress in my foil drive assist contraption, just getting some interest back due to wintery lack of wind… But from previous projects, those batteries have been very dependable, and able to happily deliver 40A for long acceleration phases.
When pairing them, you need to make sure they’re both in the same condition. Ideally, both starting from new, and both getting charged and used at same time, to keep a similar number of cycles on each. If you don’t mind those constraints, or the lower power density, or the 10S / 36V voltage limitation, then they can work. A modern12S3P would easily outperform it on every front. Aside from price and modularity.
thanks for the response, I saw a video where the guy used two 6s3p’s which is what I was searching for before I saw your post
I use 2 6s2p packs and 2 6s3p packs. With 2p I get around 45 mins. 3p gives me over an hour.
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Are you connecting them in parallel ? I’m guessing something like this would work
12s3p Samsung 40T Battery
I connect in series to give 12s2p or 12s3p. One set uses molicell p45b cells, the other, ra50 cells.
Highly recommend going for new tabless 21700 cells like Reliance RS50 or RS60 or Tenpower 60XG. The increase in run time is huge over something like a Molicel P45. I just ordered 36 of the Tenpower and paid US $5.50 per cell. That’s from Shenzen Vapcell Technology. I’ve ordered heaps of cells from them and they have been excellent to deal with. Greater discount over 120 cells
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Can confirm, I built a 12S3P pack from reliance RS50, I can get 600Wh out of it (according to metr log).
RS60 would be even better but they were prohibitively expensive at nkon last time they were available.
I have a batch of RS50’s that will be delivered next week for a 12s4p build. They are a good price @ $6.25/cell if you buy 50 from 18650 battery store. For people in the U.S. I highly recommend 18650 battery store for cells. They ship fast and their customer service is great.
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