[ SOLVED ] Bms cell order? does it matter? ANSWER: It absolutely matters

I remember which order they were in on the connector

Red Black Blue White Yellow Black

From left to right

What is this?


Never mind, I get it, those are the bms wires

Uhhh Well I though it would be easier than soldering so I stuck all of the wires from the ten pin into the male connector of the 6 pins

Yeah exactly

Battery 1 Red---------Cell 5 Black-------Cell 4 Blue--------Cell 3 White------Cell 2 Yellow-----Cell 1

Battery 2 Red---------Cell 10 Black-------Cell 9 Blue--------Cell 8 White------Cell 7 Yellow-----Cell 6

So if I connect the balance wires in that order it will charge?

I would connect the balance wires from the batteries directly to the wires from the bms balance connector. You can solder them together and insulate them with shrink tube or use small crimp connectors. I’ve done it both ways and soldering them makes the least bulky harness You will need to use a volt meter to make sure which black wires are ground and which are cells 4 and 9

Damn it

Well if it helps I already pulled apart and old turnigy 5s battery and the black wire on the right is soldered onto the negative wire

did you already remove the original battery balance connectors?

No I pulled off the shrink wrap and yellow tape to look for the black wires

If you have a hobby charger, you should fully balance charge the packs before putting them together in series and connecting them to the bms. Otherwise, if they are not closely balanced, the bms will struggle to fully charge them.

Yeah I already did that stuff. They are both at 18.80 volts right now

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Here is what hobby king customer support told me image

I thought that you had removed the original battery balance connector. the ground balance wire is always on the opposite edge from the Red wire. That is a standard.

I think that diagram that is supplied is actually wrong, I’m 99% sure that the b1 lead goes on the left hand side of the bms balance connector. It says the order on the bottom of the bms. I could be wrong but that’s how I remember seeing it. I can open up my board to show you guys if needed

You have an MBoard bms?

right that is what the guy from hobby king said. I never removed the original connector, I just stuck the wires coming from the ten pin connector into the other side.

Nope, but the identical one from eBay, it works fine just has a low balancing current.

And that diagram seems to be correct I found some images of the back side. Damn it…stupid memory getting shit wrong

Yeah Mboards gets his from that eBay China seller

What I did on my builds that worked well and would work well in your case is to get 2 balance wire extensions that you plug into the battery balance connector and then cut the connector on the other end of the extension off and connect the wires directly to the balance wires from the bms either by soldering them or with crimp connectors. That setup makes it easy to maintenance or replace your packs if need be. Make sure that the extensions are not connected to the batteries when you cut them and connect them to the bms harness. It’s very easy to short your battery if it’s connected.