This is a battery thread so Iāve got a question regarding them:
If you have a top mount box, would you consider it worth your time to drill through to have the charging port on the outside, or just crack open the lid and snake the plug in?
If itās on an emtb, would that change your answer?
Iād just leave it inside. That way itās better sealed against water. Well that is if the box is water proof
if itĀ“s an easy thing to open the box, than just let it inside. in case you use a 8-10a charger (i donĀ“t reccomend that, but in case you do), you also can just use a xt60 as charge connector without worring about how to get it sealed right. just take it out, plug it in, and you good to go.
I built another pack. There might be some useful images for others, or someone may be able to add suggestions.
Uploadingā¦
I like the caulk gun.
I bought a roll of I think 25mm wide nickel strip for doublestack or foldover, thinking less points of failure and more current handling.
Can also fold over the top of singlestack p groups, ending up like a pcb pack. Ah I have a partial photo (board is perpetually unfinishedā¦)
I like it. Many ways to skin a cat!
Iām guessing here is the point where thereās super fish paper insulation?
Thereās actually fish paper running under the balance wires. You can kind of see it near the top when the wires take a right turn. Segmented and overlapping (for flex). And the blue square at the top, I printed little wire combs and hotglued onto the fish paper to keep all the wires running clean, and to give a little protection to the wires.
The series joint at the bottom is connected with XT150, giving me the option of using a hobby charger to balance charge or health check each of the 2 sides separately (with a balance lead splitter).
But dammit, the 2 subpacks are joined permanently by one of the balance wires, so canāt balance charge both subpacks at the same time.
Normally Iād put a dedicated hobby charger compatible JST on each subpack (7 cell for the left, 6 cell for the right) and make a harness to combine for the 13s bms, but space is so tight tight tight!
Oh and I originally put the fuse and loop key at the bottom on the series join, but that same pesky balance wire keeps things connected in series.
What welder are you using in that top pic, is it just a solenoid one? or arduino powered one
I donāt think its in any of the pics. Itās this one. I have it on a chunky great battery. Worked very well straight out of the box.
Thanks, I couldnāt see it fully as it was in the top corner. I canāt really bring myself to buy a spot welder and battery just to make one battery.
Iām currently looking at just getting a cheap control board and microwave transformer or soldering the cells with fine wire to minimise heat. What do you think?
I hear the microwave transformers have worked well for some. There are people who swear by soldering but i think this is the domain of highly skilled solderersā¦ You could always find a kindly soul in your area who could weld your groups for you?
I live in Aus so there arenāt a lot of people and shipping lithium Iāve heard is a pain in the ass. I might give the microwave a try as Iāve already got most of the stuff and Ill just steal my mums sewing machine foot pedal lol.
If all else fails I might see if @TinnieSinker could help me out, he has seemed really nice and helpful so far with questions Iāve had
Is that 3/8 inch tinned copper braided wire?
Thx. I like using that for my series connections also. I admire your work. Your attention to detail is impressive!
Very kind words, thank you.
Looks really nice! 
The balance leads are fused? Which ones?
What deck is that, looks cool?
Nope. The balance leads arenāt fused. The deck is a Bustin Royce Pro. Iāll probably have to use a different deck. Unless I can get a little creative.
