Li-Ion Battery Packs

[nikk777]

They all read 4.18v or something close to that. they are 18650 3000mah batteries. I have resoldered them to see if the joints were not connecting well. Also considering battery holders vs. soldering together....

[beavis4ever]

Has anyone made packs with 14500s with 4 cells? I would like to make 2 parallel packs and then wire them in series. I'm sure it is possible but wanted people's opinions and experiences. Thanks!

[Sunrider]

If you mean 4 cells for 7.4v than yes. Many use these.

[beavis4ever]

If you mean 4 cells for 7.4v than yes. Many use these.

Yes. That is what I meant. I didn't see any setups like that in this thread so I wasn't sure. Wasn't really sure what to search for either. I tried 2P2S but found nothing. Thanks!

[Marco]

I noticed in the tut on the second page he wired the negative lead to the bm of the pcb but the pdf file for the 7.4 v pcb from the tcss shop says this:

Terminal explanations

1、B+： Connected to the second battery’s positive terminal
2、BM/COM： Connected to the first battery’s positive terminal
3、B-： Connected to the first battery’s negative terminal
4、P+： Connected to the battery’s output or the charger’s positive terminal
5、P-： Connected to the battery’s output or the charger’s negative terminal

So you should wire the positve to the bm?

Can you check my diagram? --> Unbenannt.jpg

[Skottsaber]

The positive and negative are connected together, so it would make no difference where on the connection to add the BM wire. I just soldered it in the most convenient place for wire routing.

[Marco]

So the diagram is correct?

[Skottsaber]

Yep

[Marco]

awesome do you have and dos and donts for wiring a pack up? I really dont want to blow my face of... Like only applying heat from the soldering iron for 5 secs max. or something like that? (is it actually possible to wire batteries without tabs?)

[Jay-gon Jinn]

awesome do you have and dos and donts for wiring a pack up? I really dont want to blow my face of... Like only applying heat from the soldering iron for 5 secs max. or something like that? (is it actually possible to wire batteries without tabs?)

It is possible to wire batteries together that do not have tabs on them, but it is a bit more difficult to do. You'll need some solder flux, some medium grit sandpaper, and a nice hot iron.