Like the title says, I'm Building a 13S2P battery pack. I'm trying to figure out how to wire it most safely and efficiently. It's been a long time since I've build a custom pack of this size & as I'm using $220 worth of 60A 3.7V 26650's, I'd like it to not explode, short, or go bad anytime soon. Due to placement size constraints, I've had to do sort of a weird pack design. My design and current progress is as follows. The 2 +'s and -'s are also cells and are the series + and -'s. They are on opposite sides of the pack from each other. S1C3 S1C2 (+1S1C1) (+2S2C1) S2C2 S1C4 S2C6 S2C5 S2C4 S2C3 S1C5 S2C7 S2C8 S2C9 S2C10 S2C11 S2C12 (-2S2C13) S1C6 S1C7 S1C8 S1C9 S1C10 S1C11 S1C12 (-1S1C13) I currently have both series, 1 & 2, wired up just as shown & have three nickle strips soldered on each | > < connection, but I don't have them wired parallel yet, and I'd also like to further strengthen the series connections. So, my questions are. Where should I add the parallel connections? Just connect every + to every + and every - to every - from each series? Series 1 cell one to series 2 cell 1, series 1 cell 2 to series 2 cell 2 etc? Where can I add extra connections to increase handling of current and amps? When I connect the 2 13s BMS's, I just connect BMS - to cell one series - that the first + is attached to and BMS +'s to each positive terminal for cells in the series, right? If I choose to install some 70amp fuses where would I install those to best protect the system but not pop random fuses & strand myself? I'm planning to add some solar cells to the system also. Where would I connect those so that power can be drawn from the solar cells first instead of the battery, but also charge the batteries when not using the bike or more than the solar cells generate, while not damaging the solar cells? Are they any other recommendations or additions you can think of? For those wondering, this will be hooked up to a 48V 40A motor speed controller & I also have a 48V 60A speed controller.