The battery builders club

k if 10awg should be fine i will sue that
only hard bit is soldering it into a xt90
thanks a lot

What does corrosion look like from these aggressive fluxes? Do the wire strands look powdery whitish?

1 Like

I use a tiny blob of hot glue at each end of the cells on both sides, just to hold the groups together while I silicone them.

If iā€™m really in a hurry, i can hot glue, silicone, wrap in fishpaper and begin welding before the silicone has set cos the little blobs of hotglue hold it well enough to work with.

6 Likes

I agree that it is super corrosive (and aggressive) and definitely needs to be thoroughly cleaned.

In certain situations it can work literal magic though.

Iā€™ve had a couple cells show some slight rust under the shrinkwrap due to exposure to it (soldered pack). Iā€™ve been keeping a close eye on it, and after the initial rust appearing it seems to have stopped getting any worse.

3 Likes

Thatā€™s a good idea, I tried my hand with hot glue yesterday did do a great job and this morning I tried separating the cells and it was really easy to do it. Plus the hot glue came off leaving the cells really clean.

Also, I went shopping for some silicon and canā€™t find neutral cure silicon, they only have bathroom type, woodworking type or mastic glue.

4 Likes

This stuff is the good stuff, approved by @b264.

GE Silicone 2* or 2+ is neutral cure.

image

3 Likes

Thanks. Iā€™ll look for this locally, meanwhile any other brand/product to look for? Anyone? In case I canā€™t find this

1 Like

One thing you can do is check the warnings. They all have something like ā€œthis product gives off X and Y chemicals as it cures, avoid breathing blah blah blahā€.
If the chemicals it gives off include acetic acid, itā€™s an acid cure silicone.
If theyā€™re something like ammonia and methanol, then itā€™s a neutral cure silicone.

4 Likes

Oh man thatā€™s really helpful, thanks Iā€™ll look for the composition next time i go to the store :grin:

2 Likes

If it smells like vinegar, itā€™s the wrong stuff.

7 Likes

:joy:

They have a really serious ā€œif you open it you pay for itā€ policy at these stores

4 Likes

After you open one, if it smells like vinegar, then pay for it and use it to seal your homeā€™s gutters. :rofl:

4 Likes

Hy Guys i got a question regarding a Battery i wanna build.
So i want to make a 16s4P battery with 21700 molicell cells => the battery will give me 180A total
for the esc i think ill go with the Ubox and for the motors ill go with 140kv APS 8085s
So the max motor amp is 125A and the esc can provide 100A to each motor.
Ad the battery is the bottle neck in this scenario i want to ask you guys if this setup will harm the battery pack in someway as its always on its limits when i set the motor amps to 90 for each motor.
Should i go for 16s5P instead?

KR and thx very much!!

I mean if you keep doing it youā€™ll reduce the lifespan and capacity of the cells, Iā€™d aim for 6p actually since P42A is only really good for 35A (you want Samsung 30T if you want serious amps)

2 Likes

This is a literal truck load of power, unless you weigh 300lbs youā€™re going to struggle to maintain amps this high for even a second.

Also battery A doesnā€™t equal motor A. You have two different voltageā€™s in and out, itā€™s not just direct current through the ESC, so you could run 50A battery and 100A motor, and it would still kinda work. 25% is an acceptable difference between the motor and battery amps.

5 Likes

What you mean with the pa42 is only good for 35a??

Mooch did some testing with it, the cell is overrated

1 Like

Each cell is really only good for 35a, 35x4 = 140a max capability.

This made me lol a little, true its overrated, but dang 35a is a ton

4 Likes

hahah ya ā€œONLY 35Aā€

4 Likes