The battery builders club

Hey hey hey, I spent about 3 years “learning to solder” with unnecessarily large wire, low quality solder and a shitty iron.

This is absolutely the case, after 3 years of hardware store stuff, I bought a Ksger and kester solder and suddenly all of the experience I had began to show. Even borrowing a friend’s quality soldering station is very likely to show you’re more skilled than you’re aware of.


10awg is wild for series connections. Double up 14 or smthn

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I’m finally in the cool kids club😎


It’s what i had on hand. But yeah, should have.

Thanks for encouragement

And @Swol_Moon very impressive :clap:



if we don’t start seeing Pickle Rick packs… I’m going to be very disappointed indeed


I need

Put a sheet of rubber in for bit more or a barrier. Then fish paper on top. That make you feel more at ease @fessyfoo @glyphiks and @Common_good?

She aint pretty but almost done. Just need to connect the BMS tonight and fingers crossed it’s wired properly.

As rough as it looks it’s still taken me many hours of work :sweat_smile:

Oh and adding a final sleeve of shrink wrap over the pack once BMS is connected and working :crossed_fingers:

Edit: already found an error :man_facepalming:. Hooked up BMS to see a bunch of weird shit. I checked my balance leads and did one to the negative. Doing this late at night not the smartest thing!

Success tonight :partying_face:


Glad to see you got it done. Congrats


Well it’s taking its first charge, still have to splice in the thermocouples but after that she’ll be ready to shrink wrap!


Nice work dude, that bms looks interesting, which one is it? Interesting choice to wire for discharge as well :grimacing::grimacing::grimacing:

It’s not always necessary but it’s considered good practice around here to insulate between your balance wires wherever they cross over each other on top of a battery. Alternatively, make the crossovers before they enter the battery so that they all branch off in order.

If you can ensure that there is no possibility of pressure being put down onto the balance wires, then it’s fine the way it is.

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Thanks man! I was so careful to build this thing right and insulated everything and then completely overlooked the crossing balance wires!! Hahaha. Good catch, I’ll add some before I wrap it, thanks for the heads up.

I originally had a daily BMS but it was too big to fit my profile so I ended up picking up a Maxkgo 200A unit. Fits perfectly on my p pack boxes I printed. I guess now I have to build another to use the Daly haha.


Thermocouples? Nice. :heart_eyes:
What are you hooking them up to for temp sensing?

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I think a lot of the Daly smart bms have a temp sensor wire that needs to be plugged in for the bms to work. I’m hooking one up tomorrow and was planning on putting the wire in the center of the battery.


Those are thermistors though (for temp sensing).

Thermocouples are a much better way to measure temp but are typically not needed for esk8. They need separate circuitry to read them and I haven’t seen any BMS that has that.


I meant to say thermistors but yeah, I’ll be monitoring 4 spots on the battery and 1 additional for my electronics enclosure.

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Quite right, I meant to say thermistors! I have used thermocouples quite a bit and it just flowed right onto the keyboard haha.

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Yeah the Daly unit I bought has one. Unfortunately the BMS was too large to fit in my enclosure I made so I ended up getting another BMS. No BT or anything on this smaller unit but it has a canbus which the vendor sent me the spec sheet for so I can use an ESP32 and write my own program to monitor everything with a touchscreen on my electronics box

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Looks very tidy. What does the inside look like? Curious how u did your series with a profile that low…

Thanks man! I am not a fan of soldered wires if there is a better option. In this particular case the battery is capable of 240 amps discharge (I built it for possible future more heavy duty use in case my old ass gets busted trying to learn to esk8 lol). So rather than attempting to squeeze some 1/0 in there I made some nickel / copper sand which bus bars that run down the sides. (.2mm x 40mm nickel, .2 x 40 copper, .2 x 40 nickel) and spot welded all that together so you end up with a flat and clean look that adds 1.2 mm of width and more than capable of carrying that amperage.

Yep looks very clean. I would suggest that you rethink your aversion to soldering if you end up building another esk8 battery tho. There’s a reason why it’s a best practice. Specifically, in a high vibration environment, it builds in some flex between p groups leading to a more robust battery. I can’t see how you’ve connected the groups together but your pack will naturally flex a bit and will also be subject to significant vibrations. If your p-groups aren’t very securely connected together, welds oriented like this have been known to fail.

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