The battery builders club

Well they are completely right imo

image

But they projected the message in a shit way with that video

2 Likes

I only say cases for bare cells to minimize the risk of shorts.

1 Like

yup easy and cheap

1 Like

Right in the video theyā€™re going after the average battery consumer, but I think the problem theyā€™re trying to address is devices being sold like a lot of vaporizers with removable lithium-ion cells.

Good morning guys. I am thinking of switching from lipo to li-ion. I need advices on building a 10s3p battery pack. I built 2 lipo 10s packs b4 so know a little bit about the danger is building a battery.
My plan is build my pack with Samsung r25 18650 cells. 7500mah and 60amp is enough for my use. Before starting I have a few questions and would like ppl here to give me some advice.

  1. 18650battery story has Samsung r25 for $2.99 each is that a good deal?

  2. I know spot welding 18650 is best but I donā€™t have a spot welder and I know soldering would damage the cell. What other options do I have besides spot welding.

Thanks you.

1 Like

You can buy 18650s from some places with tabs already welded to them and then you can solder to the tabs :+1:

A lot of guys here like to use the NESE system as well. Iā€™ve never used it but I think itā€™s a great idea. More info here - NESE, the no solder 18650 battery system

4 Likes

Burned out 5 of them

Got sick of them failing and went for a weller one
Especially since I cant find them locally

1 Like

Well my first did hold up one year till the tip was done. Never had one fail and for 8$ :man_shrugging: I donā€™t mind to buy one new every year.
But others who bought some in similar price range with plastic grip didnā€™t have had so much luck. So there is that.
With a weller you never go wrong if you have the money to spend.

3 Likes

Animal.

25R is a 15A cell (you can check via google). 30Q is a 20A cell and a great upgrade in every way, even price.

1 Like

You just made me realize that all the complicated solder jobs Iā€™ve done with thick wires where Iā€™ve tried meshing the wire strands together or wrapping them around one another were pointless because this is just as good as long as you have enough solder :man_facepalming:

2 Likes

If you use too much, is hanging there like raindrop. That solder job was a 10 awg wire to 12 awg for a bms.

I could be wrong but all the website that sells Samsung 25r said the max discharge is 20amp.

Their voltage sag is huge

1 Like

There is often a gap between manufacturer supplied specifications and real world use. 25R and 30Q are very popular cells, and the internet has much practical data.

1 Like

Wrapping them makes them so much easier to solder thoā€¦ i donā€™t know what kind of voodoo magic @Mainflow used here to keep them all so neatly together while he soldered :joy:

Also, wherever possible, solder should be used as an electrical connection only, not mechanical. If that joint heated up enough, it could easily come unstuck :man_shrugging:

Wire wrapping is a good practice imo.

7 Likes

It was only supposed as a electrical connection, not mechanically. :joy:(That job was for the new baja bms)
Basically I learned soldering in 10 minutes a few years ago :rofl:

2 Likes

So how is it mechanically connected?

2 Likes

I just pressed the straight wire against the thicc wire and let it cool down. Nothing is wrapped.

Well, if weā€™re going to be really technical here, Lineman splicing is the only acceptable way to join wires for ultimate strength and bond in safety oriented industries like aerospace. This does work for multi-strand too, but it does create a bit of bulk at the joint. In applications with multiple wires side by side, the wires should be cut in a staggered fashion so that no 2 joints will sit side by side in their resting position.

TL;DR: Ainā€™t nobody got time for that.

13 Likes

:heart_eyes::heart_eyes::heart_eyes:

Donā€™t mind me, Iā€™m just jealous of Yannickā€™s voodoo soldering skills :joy:

3 Likes