looks like you just missed the battery terminal
5 Likes
Thing is I got it to work on my 12s4p, sanded the cells the same way, basically the same nickel tooā¦ All of those cells were totally sanded
Yeah that one I did miss, but on the next belt it looked holes through on the negative ends too that went the problem (that was my first weld off the month so needed some practice)
So I found this video demonstrating a 12s8p battery build and I appreciate his effort in creating it to share!
I did notice a few things that could be changed for better safety but just wanted to hear any thoughts you guys might have. One question I have is whether these series connections would be adequate to pull the rated amp of the battery?
When you buy salvaged cells try to get them not sanded. Also try not to sand them yourself either. Remove the debris with pliers. In case you really need to sand them do it very carefully. Do not remove metal.
Michal at endless-sphere sometimes has cells welded only on one side. That makes things way easier.
I was nervous about this as well. Fortunately, nickel is very soft compared to steel and comes off easier, so with a careful hand and a good setup I felt confident in removing nickel without taking steel. If youāre sanding and itās sparking, its taking steel 
maybe next time, Iāll try and avoid sanding and see how it goes
1 Like
I mean I didnāt remove steel, I barely touch the cell so the nickel gets removed and the steel is only scratchedā¦like thereās barely even any dust after 47 cells
1 Like
@Arzamenable How are those BatteryClearingHouse LGDBHG21865 cells so far other than Fedex drop-kicking the package out the back of a moving truck? Iām planning on buying some tomorrow, just wanted to get your first impressions.
1 Like
Cool. Iām doing a 10s8p so hopefully I get enough good cells for the whole pack and hopefully a spare p group.
Thought you guys would enjoy this monstrosity
2 Likes
The lack of attention to detail and the crooked nickel strip really irked me but the machine is cool for sure lmao
2 Likes
While I find this video to be helpful, I would like to make a running list of ways this battery could be improved so others can watch for a grasp of the subject but decide for themselves if other steps are needed in their project. I will update as suggestions are made.
- Fish paper all the P-Packs.
- Get rid of the electric tape and painters tape. Use kapton tape and fish tape.
- Round the edges of the nickel strips.
I have discovered that home made welding pens are ASSā¦I swapped back to my long prongs and the welds are perfect now (except that one, forgot the counterweight)
Yeah, for the handheld probes to work well, you need
- Very Thick Wires. Talking like 6AWG.
- Preferably one probe in each hand so you can get the pressure right on both points simultaneously
Free
5 Likes
Damnā¦is the resistance of the wire really enough to drop the current to that low a level?
And does anyone have 30" of heavy gauge they would like to send? Not making another pack for a while so no rush and it would make shipping dirt cheap, and obviously Iāll cover the cost of the wire and shipping (I just donāt need 10ā)
this.
abso-fuking-lutely
that clip you showed with the jumping leads, was most excellent , and perfectly demonstrates the energy dissipation by slamming so much current into the little 10g wires over that 3ft round trip.
heat is generally the mode of energy dissipation in less extreme cases 
3 Likes
I thought the magnetic field generated is the the electrical impulse not the actual current, so less jump would mean itās got to much inductance
1 Like
Regardless, when hundreds or thousands of amps are flowing, milliohms matter. Double the length of the wire (or make it half as thick) and you double the resistance, which doubles the power loss. Going from 10AWG to 6AWG will drop your wire resistance by more than half.
Donāt discount the comment I made earlier about pressure either. If the resistance of the electrode-nickel-cell sandwich at each point is too high due to low contact pressure, youāll get blowouts and/or weak joints.
If the contact area of your probes is too large (not pointy enough) the resistance will be too low, and youāll get weak joints.
1 Like