The battery builders club

Get a pair of hemostats and clamp them onto the wire just before the insulation starts. It’ll act as a heat sink and keep the solder from wicking so far.

This also works equally well on copper flat braid too.

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My problem was fixed by using a large flat head screwdriver pressing down hard. I also stripped off 3/4" of insulation instead of 1/4"…this helped alot. The silicon holds the heat alot. I think thats why uninsulated wire can hold soo much current b/c of superior cooling.

I had borrowed a Arduino Spotwelder. I guess i didn’t have the right settings for that side of the pack … I opened seven more packs to test the welds and couldn’t pull the nickle off, even with pliers. I guess it was just the one pack. I just ordered a K-Weld to fix it …the weather isn’t ideal at the moment anyway …

Interesting. I’ve seen this technique used before. It must be a combination of having them clamped in the right place and having a hot enough iron so as to heat up the unclamped part hot enough while the heatsink stays in place

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It depends on the switch, and what your expectation of current draw is.

I build power banks for the Onewheel, using a 7s4p pack inside an amp box. The pack discharge is direct into the converter, through a switch. The switch I’m using is this:

https://www.amazon.com/gp/product/B00004WLK7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The specs listed there are much lower than they are on GB’s own website. Their page for that switch list it as rated for 10 amps I believe. My setup pulls about 11-13 amps depending on the battery level, but no part of the switch or its wiring even gets warm after running for an hour.

I’m stepping up 29v to 63 usually, and it runs well. If you’re stepping up 42v to 50/51, then you’ll likely have less current draw difference.

I like the switch. It works, makes for a physical circuit cutoff, and it’s small and unobtrusive.

I’m currently using this converter, and so far they’re fairly solid without the need of an antispark switch:

https://www.amazon.com/gp/product/B07TB7FBWQ/ref=ox_sc_saved_image_5?smid=A1HVCTHF5PHDZF&psc=1

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It doesn’t have to stop the heat entirely, just reduce it a bit so the solder won’t melt beyond that point.

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Would you say that this daly bms is lifepo4 or lion. I can’t read the writing and I’m sceptical.

12s 36v means lifepo4

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Anyone done a 12s8p 21700 for redember 44 in the @eBoosted DS? Need to build one but getting hands on the enclosure would cost many monies.

Photos would be appreciated

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looking at some different cells and was wondering at a 12s6p battery on 4wd what cell will pack a punch but still give decent range
p42a? 40t? 30t? (only issue is p42a is sold out on fogstar for 2 weeks or more)

P42A outperforms the 40T by a little.
For up to about 25A per cell the P42A will run for a bit longer.
When much above about 25A per cell the 30T is the better choice.

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Is that continuous or burst?

If I want hursts of 30amps but mainly 20 or so?

Edit read your p42a posts and really useful thanks

It doesn’t matter. For a li-ion battery the performance does not change for any discharge longer than a few milliseconds. The temperature changes the harder and longer you run it, of course.

If you have bursts at 30A then you are running them at 30A and the voltage sag will be appropriate to those 30A bursts. I recommend choosing a battery that runs efficiently at 30A.

If you are running it for shorter amounts of time you can run it harder. But I can never recommend going over the rating as I have no idea what the internal condition of anyone’s cells are. I have to assume the worst.

Each of us can choose how hard to run our cells though.

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So what cells would you recommend
30t?

Well If you do 6p its not a problem.

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I already told you above. :grin:

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Yep re read and saw

Thanks man awesome stuff

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Make a 13s battery that is split into a 6s and 7s to work on the 12s balance charger I said.

It’ll be fine I said.

Turns out it is fine and it works, but it’s been a head fuck.

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Cool. You disconnect the two packs every time you charge?

The loop key connects the two batteries. So when i pull the loop key to turn the board off, the two batteries are disconnected from each other.

The issue I have discovered, is that when both batteries are plugged into the charger and the escs are connected to the battery, there is a very small amount of continuity which is enough to light up the LEDs on the escs, but not enough to power them on…

This seems highly suspect to me, so I am adding an extra loop key between the battery and escs.

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