Im gonna go back and read this a couple of times, just to make sure I understand. I really appreciate all the help.
Just becareful when connecting lipos together. Ensure using multimeter to know there are no shortings.
Here ya go! I went off this following page for the wiring of everything involved. The ESC is directly connected to the battery because it overrides the current limit of the BMS.
Just to confirm my messy paint skills, the battery on the left is NOT connected to the BMS via the balance lead, and two of the pins between the two batteries are connected.
Please be careful while setting this up, while I am pretty sure what my diagram is correct, I have had a lot of people screw up because they thought polarity didn’t matter/I might have made a simple mistake.
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That is AWESOME! I will update the drawing when I get back to work Monday and upload it for everyones use. It will likely be a month or so before the BMS arrives, but at that point Ill test and post the results. This could be a really cheap way to get very simple battery management fir our boards. Thanks to everyone for the help.
I have never setup a BMS,
but this seems really strange because you bypass the bms completely when running your board. Is this a special way of wiring? Thought you had to have the BMS inside your “main” loop. This way your bms won’t be able to cut off + the fact it’s rated for 60A is not being used, the amps the esc is pulling is not going through the bms.
Or am i wrong?
Like I said, I bypassed the current limit of the BMS in that wiring diagram. The BMS is rated for 30 amps and an eboard can draw quite a bit more than that.
I’m stupid, didn’t read what you wrote ! My bad !
Not stupid, just learning. We’ve all been there!
Just for reference, I (200 lbs) draw about 40 amps, going 15-20mph uphill on my dual setup. So you may actually be okay with 30, but I would probably follow the wise advice of @VladPomogaev, 30 is a little low. I may add to that, if you are going to bypass it, then I’d see if you can save a few bucks and get the same one but just with as low of a discharge current as possible, since you’re not going to use it anyways. I did that on my board. I’ve got a 10A BMS, but since I bypass it going to the ESC it doesn’t create an issue.
I don’t want to step on anyone’s toes but you really want a more stable chemistry when using a BMS. Stick with cells that have an internal fail-safe like a123’s or 18650’s if you want something you can just plug in and walk away.
@mmaner Your balance lead wiring is incorrect for this bms. You don’t use the black balance wire from either pack. You only use the 3 positive wires from each pack. Each positive wire represents 1 cell. Starting with the pack that provides neg lead to the Esc. First cell in that pack is cell 1 The pack providing pos lead to Esc is the last pack and the last cell in that pack is cell 6 The red wire is always the last cell in a pack. In your case the red wires are cells 3 and 6. You’ll have to test the other 2 color wires with volt meter to determine which is cell 1,2,4 and 5 The black wires are ground wires and are not needed with this type of bms.
I’m not sure exactly what you are saying, but I think you are referring to the numbers which are on the pins of the balance connectors, right? In that case yup, they are wrong. I was going off the colors and the order of the wires.
@mmaner i’m not referring to the the numbers of pins. I’m talking about the balance wires from the batteries. You have the ground balance wire from one pack connected to the red balance wire from the other pack and both of them connected to the bms balance plug. That is completely wrong and might short out the bms You connect the main power leads in series but not the balance leads When you connect a Lipo battery to a bms, you omit the black ground wires and only use the color positive wires. The purpose of the ground balance wire is for use with a balance charger.
You have the ground balance wire from one pack connected to the red balance wire from the other pack and both of them connected to the bms balance plug. That is completely wrong and might short out the bms You connect the main power leads in series but not the balance leads
No it’s not. That part of my configuration is correct. Here’s a 3s to 6s balance lead converter. You can clearly see how the positive and negative leads are connected together.
When you connect a Lipo battery to a bms, you omit the black ground wires and only use the color positive wires.
Yes. If you refer back to my diagram you can see that the negative of the left battery is disconnected. This is because it is the ground of the entire battery pack. Since this is two 3S batteries in series, you still have to connect the center cells together, which do not count as the ground since they are in the “center” cells.
@mmaner It is wrong. Those 3s to 6s adapters are for Balance Charger balance ports. The Bms is different. The Bms does not use ground wires from the battery balance harness. That is why the Bms balance port has only 6 pins not 7. A Balance charger port has 7 pins. Trust me, I have actually wired Lipo batteries to a bms. A 10s bms wired to five 2s lipo batteries in series. I know what I’m talking about. I you wired a bms according to that diagram, I think you will blow up the bms.
Well the ground of the entire pack is not connected to the BMS balance port. I don’t see the problem here.
@mmaner The problem is the red balance wire from this pack connected with the black balance wire from the other pack
Yeah, that’s how you wire two packs in series. Black to minus.
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They carry out the same function. Fine, if you think I’m wrong, so be it.