The battery builders club

Thank you @Evwan @BenjaminF for the feedback on the helping hands. I’m really over spent for my build so it would have really hurt if I had gotten it.

1 Like

That fan is also super low CFM, barely moves any air in other words.

1 Like

Is there one you recommend? This? 41l+3Q5swrL.AC_SY780

Have this too. It also falls over lol. The magnifine glass also distorts the other side making it hard to use. Adjusting it also sucks.

2 Likes

I got used to that one and got pretty functional with it. Not to say it is good or there aren’t much better stuff out there.

1 Like

This made me so fucking mad, thank god he didn’t burn his house down.

3 Likes

Horrifying battery work indeed.

1 Like

This is the shit that gives DIY a bad name. Gross negligence, no consciousness for safety at all.

5 Likes

I’m trying to understand. What I saw was he didn’t have a bms?? (how can you not have one!) And he soldered the cells :nauseated_face:

1 Like

W…T…F…:face_with_symbols_over_mouth::face_with_symbols_over_mouth::face_with_symbols_over_mouth::face_with_symbols_over_mouth::face_with_symbols_over_mouth:

Ignoring his spectacularly unwise decision to solder the cells, not use a BMS, and use an almost sealed metal box with no provisions for the release of trapped gas, cell-level fusing doesn’t provide protection for anything other than excess current at the cell.

Overcharging, overdischarging, and excess heat can all cause cells to go into thermal runaway (catch fire, possibly explode) and the fuses can’t stop it.

If a burning cell shorts out others in the p-group then the fuses could potentially help but the heat from the burning cell can still spread to other cells, forcing them into runaway too.

Not being able to quickly open the box to flood the pack with water was also a grave design error. It’s the quickest way to put out a li-ion battery fire since it brings the cell temperatures down below the thermal runaway threshold, stopping the violent reactions. Then all you have is a “normal” plastic, paper, and solvent (battery electrolyte) fire.

There’s no metallic lithium in a rechargeable li-ion cell so water can’t react violently.

Well, I’m glad he was able to save a few dollars by using salvaged cells and no BMS though. :roll_eyes:

All sarcasm and anger aside, I’m glad no one was hurt and that he didn’t set the house on fire. That soot contains a lot of dangerous stuff though, including cobalt. I’m hoping he treats this cleanup very, very seriously.

9 Likes

I do safe stuff.

17 Likes

Given how much care he put into safety on the front end, I somehow doubt he will put that in on the back end.

That’s very crafty of you Al, I like it :grin:

11 Likes

One more standard for us, thanks.

2 Likes

Group hug for Mooch

3 Likes

Where did you buy that nickel?

1 Like

Local dude, no idea where he gets it tho

3 Likes

I saw these on sale… 3,000mAh/15A cells.

Any idea what they’re a rewrap of?

I’ve used the Epoch rewraps of the Samsung 50G and they are excellent. I’m curious about these, price seems decent.

1 Like

My patrons have seen the preliminary test results for the Epoch 15A 3000mAh 18650, full report being posted publicly this week.

4 Likes

This is the wiring diagram for my 16s 320a bluetooth bms that I will be wiring for charge+discharge. The connectors for the c- and b- are these circle connectors. Do I solder my battery 10awg wire onto this circle or do I solder a circle connector to my battery wire and then connect to the bms wire through a bolt? I’m not sure how much amps I will use - will the bolt be okay for this or could it come loose with vibration? It seems most people max at 60a peak from their battery? I will be using 9inch wheels with m1 at drive + fs bh 6834 140kv motors at 16s.

1 Like

Does anyone have a bunch of wide nickel strip you can spare for a pack?

1 Like