Looking at these nickel tabs extended on top of the battery where the cables are soldered to, I’m wondering how many layers of them people tend to use:
In this picture it seems only one per group but it’s hard to see whether there are hidden layers beneath.
I find that stacking several layers is a pain because when you bend them the layers tend to separate from each other. It’s also hard to spot weld them together on the part that is far from the battery pole.
Would like to hear from your experience some good practices on this subject.
In that pic there’s only one layer of nickel. Its so wide it doesn’t need to be stacked. A pack that size would never need double or triple stack when the nickel is 30mm or more in width, even if it is only .15 thickness. .2 or .3 definitely wouldn’t need it.
Most packs don’t need double or triple stacked nickel. Single layer on your pgroups and then jump them together with copper wire or braid.
I can source 0.25 mm width x 0.20 mm thickness nickel which, according to your feedback would be enough. One layer only will definitely simplify things a lot.
as I discovered today when my Flipsky blew up after 3 rides a while back, it left a black char on the esc. I though that was the extent of the damage.
since I’m waiting for my go-foc dv6 to come in, I decided to hook up my 12s6p battery-pack to the balance charger and put it into storage mode, kept getting error!
discovered part of the “wide” nickle strip was blown out at the end where the wire connects to the xt90
the missing strip, maybe like 4mm across just vaporized!
In the formats of most battery builders, the nickel is welded to the cells, the copper wires or braiding is where the amps flow through. Nickel doesn’t really see the same current as the wire.
I agree, but the flow is split between the cells in the p groups. It’s the series connections where all the amps flow together. I know that’s over simplified, but that’s why we can get away with single nickel strips on the p groups and want to beef up the ampacity for the series wiring. Not an expert by any means but that’s the theory afaik.
Agreed. An experienced builder is going to know how to make a safe pack, whether its with nickel series connections or not. But when giving advise to noobs, I think it’s always safer to advise them to make series connections with wire or braid. That way you avoid a situation like this:
Definitely. Proper pack layout is a science, and there is no substitute for experience, but some general rules of thumb can help make things easier to understand for noobs.
Nothing beats first hand experience, even after doing all your DD lol
First time I built my battery pack, I plugged both balance leads into the parallel charging board and there was spark, smoke and melted balance wires!
My wife was like what the heck is the smell lmao
I was in a panic and froze and knew enough not to grab the wires with my bare hands and break them off. I was expecting the battery pack to blow up and catch fire.
I have no idea what happen as I tested the balance leads and voltage on each multiple times. Suffice to say that is/was the last time I would use a parallel charging board and bought a balance charger with dual charging.
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when my Flipsky blew up after 3 rides a while back, it left a black char on the esc. I though that was the extent of the damage.
