Please review my battery pack so I don't make a šŸ”„

I wish I had read this yesterday. Guess I need to add some extra protection between the p-groups :sleepy:

IMG_20190415_183208_crop

4 Likes

Has that BMS been working well for you? I bought an identical one recently but noticed itā€™s missing a component:

none of those packs are mine

2 Likes

Ah I just realised

Sorry to interupt the chat but i just welded part of my battery together and the left cell is 13 degrees hotter then all the other ones. I dident short it out or anything.15553633848031773625266 just a bit confused

Heres another picture15553648185641170845214

That 10AWG wire is good for 55A continuous and 110A for <10 seconds.

That 0.25" tinned copper braid is good for 40A continuous and 75A for <10 seconds.

Double those for double the rating.

Is this a normal thing for the cells to do. I replaced it with a fresh one and the same thing occured

They might be balancing. Measure the voltage on the cell and the voltage on the P-pack. If they are off at all, they will immediately begin balancing (charging the lower one, discharging the higher one)

You donā€™t want more than a 0.1V difference and itā€™s better if they are the same before the weld.

5 Likes

Ok that makes sense now. It was at a lower voltage than the others. Should i just weld it back on and leave it or charge it up to the same voltage?

Each strand of the tinned copper braid is good for 40A, so I have 3 lines of it connecting each series together. Thatā€™s fine, right?

Iā€™ll double up on those power lines from the battery to ESC. Would it still be ok then have them conjointed back into a single 10 awg wire right before the ESC? The ESC has power input as single 10awg with a xt90 connector. Would it be fine to continue using these or should I desolder them from the ESCā€™s pcb and replace with something more heavy duty? (Flipsky dual)

If itā€™s within 0,1V you should weld it in. Make sure the temperature goes back to normal. If itā€™s not within a tenth then donā€™t weld it in until it is

1 Like

Yes, thatā€™s good for 120A continuous and hundreds of amperes for under ten seconds.

Just make sure if the pack can flex that the braid is set up in such a way it wonā€™t fray over time under heavy vibration.

Thatā€™s approximately equivalent to three 12AWG wires.

1 Like

How should i wire up my bms1555638262781195232915 not sure how to set this up.

1 Like

Give us a clear pic of the BMS like below so we can see the solder points. A model number and if you want to use for discharge or charge only?

image

1 Like

Sorry about that. Its a discharge only bms from @thisguyhere 1555639804436158311331http://www.esk8life.com/bestech-d140-10s-bms

1 Like

Looks like a bestech D140. If thatā€™s the case you can find the wiring diagram on the bestech side and itā€™s a charge only bms, not a discharge bms.

Also, what happened here???

image

1 Like

Im on phone so itā€™s hard to make a good drawing but I think it should be like this. Someone else needs to confirm though before you power it up. Also add a fuse to the charge circuit.

image

2 Likes

Maybe to add, if it is a D140, itā€™s ok that first pin of the jst plug is not used. Itā€™s the balance minus and on the pcb connected with the B- thatā€™s why itā€™s left out.

1 Like

I have 2 x D140 . On one the first pin of the jst plug is missing. Whatever you do, solder the B- first before plugging in the jst plugs.

12 Likes