Building a battery pack- safety related questions

[shawnm]

Building a battery pack

I’m ready to build my battery pack (24s 78ah LiFePo4 for a 72 volt system for an EV) and have a couple of safety-related questions before I started. I’ve read Micah Toll’s book on how to build batteries and also watched many videos on YouTube, but I want to verify a few things before I start. Here’s by list:

• Setting up for top balancing: I have a 0-30 volt battery charger and interconnects rated for 105A. I’ve seen Will Prowse use what appears to be a regular metal ratchet set to attach the nuts/bolts to the battery. He says in a video that he has a “composite” ratchet. I can’t seem to find those. I do have Class 0 & 00 rated gloves. I’d use a regular ratchet. Is this solution adequate?
• When taking apart this top balancing setup I’ll disassemble it using the same tools. I know from working on vehicles you should remove the negative first. Same thing applies here?
• Assembling in series: I have a method to compress them in a custom electrically isolated box. I will use the same tools. Any cautions here?
• Are there any issues with touching the insulated part of the interconnects when they are on the cells?

I’d rather ask obvious questions and be safe to make other mistakes! Thanks.

 

[OM617YOTA]

1/4 in. Drive Teardrop Composite Ratchet

Amazing deals on this 1/4In Dr Teardrop Composite Ratchet Wrench at Harbor Freight. Quality tools & low prices.

harborfreight.com

Here's the currently available composite ratchet. I've got one of the old version that Will uses, and quite like it. Had it long before I got into solar or could appreciate the voltage isolating feature.

I've also wrapped my 10mm wrench in electrical tape, leaving only the last part of the jaws as exposed bare metal.

 

[Sanwizard]

1/4 in. Drive Teardrop Composite Ratchet

Amazing deals on this 1/4In Dr Teardrop Composite Ratchet Wrench at Harbor Freight. Quality tools & low prices.

harborfreight.com

Here's the currently available composite ratchet. I've got one of the old version that Will uses, and quite like it. Had it long before I got into solar or could appreciate the voltage isolating feature.

I've also wrapped my 10mm wrench in electrical tape, leaving only the last part of the jaws as exposed bare metal.

I have the same one. Very reasonable price. Tape works ok too though.

 

[Browneye]

Stopped at HF, which I rarely do, and got both 3/8 and 1/4 composite ratchet drives. Just outstanding. They're actually really nice! I doubt I would try to rebuild an engine with one, but perfect for battery work.
Spent another hundred bucks on ancillary junk I just had to have. Win-win!

 

[jsmetalcraft]

I have had the Composite ratches for years. They have served me well and I like them or maybe it's the feel over the standard chrome. Never thought about them for building a battery. Will have to invest into another just for that purpose when the time comes.