Let me explain my situation first; I’m working on building my Electric Longboard and at the moment I’m working on the battery for it. Currently I’m trying to use 2 3S 5Ah LiPo’s in series to drive my board and I’m trying to setup the BMS for it. Anyways right now I’m trying to charge the battery through the BMS and I’m having some trouble doing so. First, when I plug the B+ and B- terminals into the main leads of the LiPo and give 25.2V to the P+ and P- terminals it draws current and starts charging the battery, great! Problem is when I plug the balance cable into the BMS, it immediately stops drawing any current to charge the LiPo. When I remove the balance plug it then immediately starts drawing current again. As you can see this is a big problem as the BMS needs to be able to balance the cells as well. If anybody has any ideas on why it’s doing this please let me know!
How can a 6S battery result in a 5S balancer cable? I know that BMSs usually omit the ground wire but that should still leave 6 cables to hook up to the BMS
@2-alex-2 yeah I have everything wired up correctly, I think, but I’m still having these problems. I’ve checked the cells on the balance leads and they all add up to the right voltages, it’s just not charging it when the balance lead is connected.
From both - should be from the bottom of the balance lead. Over next day or so I will be wiring mine up but first I’m testing what D- is for as I think that should be the discharge - not P- so got the check first.
@2-alex-2 HEY! So I figured out my problem! I needed to be giving it 26V on the P+ and D- NOT P- terminals! At ~26.1V it draws around 5A though changing the voltage will change how much current it draws.
For charging or discharging as I was in contact with the seller and he garanteed me that D- doesn’t need to be used. So I have borrowed a voltage regulator to try and figur out everything.
Yea I have the 5a version but haven’t finished wiring it up. So what do you have where? As I was going to wire up B-/B+ battery then P-/P+ for charging then have a led indicator attached to D- as a discharge which should then indicate weather one cell is down.
I was originally following @VladPomogaev instructable HERE and he was using the 5A version so there might be a difference between the two other than the amperage it can handle.
@2-alex-2 yeah the SMD resistors are getting very hot on mine to but that’s because it’s fully charged. I don’t actually think that I shoiuld be using the D- terminal because it’s not properly driving the gates of the MOSFET and there getting very hot. I think that my BMS may be broken… So don’t use the D- port because I also don’t know if it will stop charging when the LiPo is full.
Yea think I had a balance lead wrong that why mine were getting hot. But D- does stop on lvc but I will only be using a led indicator on D- and charge through P-/P+
