Many questions about li-ion pack

[Dunkirk]

Hello!

I am new to li-ion batteries. I have been using lipos so far. I want to build li-ion battery for my skateboard. I have room to use 20 18650 batteries and it would be 10s2p pack. I think that LG HE2 2500 mAh 20A batteries would be good to my project. Or is there a better one to go to? I have VESC so I can manage my amp draw.

I have two options what I have been thinking and I like to hear your opinion. Because this battery is for skateboard it must be slim, so I don't want to pile batteries.

1. I make two separate 5s2p batteries and connect them to series with a series connector. This would be the cheapest option, because I have already a lipo balance charger capable of 6A charge. These batteries are rated 0.5C charge rate. Meaning that when I parallel charge them I charge them at 5A?

2. This second option is to make 10s2p battery with a BMS. This is where my knowledge stops. Can anyone provide any kind of drawing how these batteries should be connected to each other? I need 10s BMS 60A, but where I can get a good one? I live in EU.. Also what kind of charger do i need and what kind of connector should I use? And because this is 10s2p pack does that mean that I can only charge it at 2.5A?

I know that there is lot of questions, but I hope that some day I can be the guy who help others! Thank you!

 

[Dunkirk]

Thank you very much for that information it helped a lot. I think I'm going without BMS and make two 5s2p packs for simplicity.

I'm going to make an enclosure that is not removable, so do I have to make output for both balance leads of the batteries or
it possible to connect battery packs balance leads in parallel while battery power cables are connected in serial? My charge is only capable for 6s.

 

[dogman dan]

You can parallel the balance leads from one series pack with the balance leads of the other, IF those two series packs are in parallel with each other at the mains.

Understand? you connect two 5s packs in series for 10s to run it. Then, only when you have disconnected the 10s back into two 5s packs, can you parallel the two packs at the mains, and then parallel them also at the balance taps. Then charge as a 2p 5s pack.

Don't connect the balance leads before you disconnect the series connection, If you do, a connector will spark and melt in your hand, which we call Kentucky fried fingers. KFF. Similarly, make sure you disconnect those balance plugs, before you go to reconnect the mains in series.