It that hummie deck? Sweet. The only concern I have is carrying 6 cells worth of current through just 2 nickel strips: it’s probably way fine in real life but I’m super cautious. Would be cool to do this foldover with like a 3 cell wide nickel sheet.
Where did you get that copper strand. Probably more conducive, but do you think it’s as stable as the flat sheets?
my thinking is resistance increases over distance. the tabs you see here are about 3mm so at that length ampacity should be well above average amp draw. i mean, these cell fuses can do 20amp at short lengths so 10mm nickel should be able to handle it. this is without any experimentation though.
i wouldn’t run long lengths of nickel, like when making serial connections.
it’s going to get secured down, insulated with kapton, the whole pack will be pvc shrinked again when it’s complete.
2 Likes
Does this make sense being rated for 40 amps?
Binge drinking and battery building.
The obvious solution is to switch to the 
's 
technicaly yes, but you’ve got nickel, just use what you’ve got.
if you’re concerned about long lengths of nickel, just double them up, and it doesn’t have to be stacked the whole length either. just double it up like half the length and it should up the ampacity.
parallel lines on the bottom are nickel strips.
1 Like
Thank you so much for all the advice and pictures
1 Like
I live in California so your suggestion tends to be my oxygen. The drinking is just comes back to bite me every year or so and when it starts it takes a long time to sober back up.
1 Like
Does it harm the cells at all if there was like a second long short/spark across two cells not connected in series? Was using scissors to remove some laptop and didn’t realize they had connected two cells. Quick spark. Still good cells? To be honest this happened a few times when I was inebriated as well just for brief seconds.
nah, you’re fine. small sparks, as long as there isn’t damage on the terminals, especially the positive (anode) end, are fine.
i usually have a glass of wine around at all times but maybe not be shitfaced while you work in explosive batteries…
2 Likes
i hear ya, i’m on about my 5th build and each build is an improvement over the one that came before it.
i think most people’s first build is a bit of a mess then you go from there.
it’s great you’re doing your due diligence but there comes a point where you just have to build it. and it being something you build, you can always improve incrementally going forward.
2 Likes
“As long as you don’t puncture a positive terminal”. When I was also a little out of it I decided to make a 10s1p, punctured the wrong part of the positive end. Started shootijg our flames. That’s partially why I’m so frightened to make my own stuff.
You can see the spot in the above pic where the problem occurred. Obviously I’ll be scraping this cell.
Grinding down terminals now. Re heat shrinking because most ripped off from the superglue
That whole shooting out flames thing is why I wouldn’t grind down the ends of cells. $160 dollars worth of cells is a hell of alot cheaper than a house fire. If you’ve got the money, let somebody else do the ghetto shit.
2 Likes
So damn mad. Wasn’t paying attention accidentally stuck a battery facing the wrong way when I was stacking them in a box. Next thing I know the box has erupted in flames
This is one thing that really stood out to me after my first build. I knew abrasion is a serious issue but I didn’t realize how aggressive it could be on a skateboard from the vibration.
On my first build the vesc caps where resting against the plastic enclosure, after not too many miles the vibration had worn a hole through the metal casing of the caps just from resting on plastic. Now I hot glue down anything that can move or be damaged from abrasion.
Pics or it didn’t happen.
1 Like
Well I’ve already tossed 6 the burnt batteries. That being said if anyone has 5 to 10 30q they can sell lemme know. It was a stupid mistake and essemtially burnt the fuck out of the positive terminals.
So the cells that were involved in the small fire no longer hold voltage. After disassembled I check every voltage of the cells notninvokved in the incident. Most were at the 4.03 from a slight charge. Maybe 3 were at 3.4 and then two were all the way down to to 2.20 V. How low can these go when fully empty? Does this mean I need to scrap these cells? I’m just not too farmiliar with how to detect bad cells with the voltage values.
2.5v is usually the minimum on the data sheet.
The cells at 2.2v can still be recharged and used most likely, but there is a good chance that their internal resistance is higher than the other cells now. So if you use them in a pack they would discharge un-evenly.
Edit. They might have already had an higher internal resistance, thats why they are at 2.2 and not at the same level as others.
The only good way to check the health is with a smart charger that can measure capacity and internal resistance.
Yeah at this point I’ll just buy a pair from amazon to be safe. Thanks for your input.