# How to use a 6s BMS with 2x 6s Li Po's in parallel

I have ordered this BMS (going to bypass discharge) and originally was going to use 2x 3S LiPo’s in series but in the end, bought 2x 6s LiPo’s and will be using them in parallel. but now have I only realised that the batteries I bought have 7 balance leads each and the bms only has 5 in total.

Have I ordered the wrong BMS? or do I just need to solder the balance leads together somehow. Sorry if this is an obvious answer I am just so confused Thanks everyone for the help.

EDIT: I was also going to originally going to follow this

That bottom diagram is confusing…judging by the first picture, B0 and B6 is B- and B+ respectively, hence you have 5 left.

What do you mean [quote=“telnoi, post:2, topic:38022”] B0 and B6 is B- and B+ respectively, hence you have 5 left. [/quote]

Your black (b0) and red (b6) balance wire is apparently obsolete and essentially replaced by bat - and +.

Though I would research that. Weird BMS.

B + number stands for the balance wire number that has to be connected. Balance wire 1-5 is marked on the PCB.

I have a total of 7 balance on my LiPos (each)

Your confusion confuses me B0 = black bat negative B1 - connected via balance plug B2 - , B3 - , B4 - , B5 - , B6 = red bat positive

Sorry, I am still confused. what do I do?

Do i just ignore B0 and B6

Basically, yes. Take a look at the diagram below for 6s and compare it to the first picture you posted. The first (b0= black wire) is ignored as well as the last (b6=red).

From what I understand, b0 is replaced by the negative battery lead that is soldered to what is indicated as b - in the PCB. Same for bat positive to b+.

Ok, thank you. so I will solder B1-B5 together then to there corresponding to the BMS?

If that makes sense

Balance lead B1 from bat 1 & 2 to BMS B1. Balance lead B2 from bat 1 & 2 to BMS B2.

Repeat till 5.

Then of course the two negative battery leads to BMS B- and the two positives to BMS B+.

I think that should be correct. Someone correct me if I am wrong.

This look like one of those very cheap bms’s from eBay. I would highly recommend that you do not use such a bms. Either buy a good bms or just use a hobby charger. This is serious stuff and if you try to use cheap junk hardware, you might wind up with a bon fire

I am only using it for charging not discharge. also I have a volt tester

I would not use them for charging or discharging. They are cheap and unreliable. If your trying to budget, You can save money on a cheap deck, wheels , trucks but not on batteries and electronics. Honestly, since your only running 6s, a hobby charger is a much better choice than a bms and brick charger. The hobby charger will do a much better job of balance charging than even the best bms.

what BMS would you recommend that isn’t too pricey then?

Bestech is number one Battery Supports or Supower (eBay name) is a close second.

Bestech has more options but must be ordered direct from manufacturer with a min order of 2. Supower can be purchased from the manufacturer’s eBay site. Both of these are name brands and proven for reliability.

@chaka was selling Bestech 6s bms’s a while ago. Don’t know if he still has any.

Here is a link for Supower:

http://stores.ebay.com/SuPower-Battery/22V-6S-High-Drain-BMS-/_i.html?_fsub=1108655119

All I want a bms for is to charge is there anything cheaper?

[quote=“Orin635, post:18, topic:38022, full:true”] All I want a bms for is to charge is there anything cheaper?