SwampDonkey
100 W
- Joined
- Mar 27, 2018
- Messages
- 227
I feel like Im cursed over here. Ive been through 3 BMS units on 2 different batteries and none seem to work. They are 48V and 72V versions of this:
https://vruzend.co.uk/products/4s-1...-li-charger-balance-polymer-lipo-60a-bms-cell
They had good reviews, I dont know whats going on. Im afraid to solder anything now lol. Is there some way to test the BMS? It wouldnt charge, and the voltage from the P-/P+ was lower than the pack voltage. Measured directly, the pack is at 50V, I get 46V from the plug. Plus, it wont charge.
I was told that I could plug it in and actually measure the voltage on the balance leads, see it increase as I moved down the red charging wires coming from the 14 pin molex plug, but that doesnt work. The 72V version is having the same problem.
Do these BMS units just suck? I wired them up just as the diagram instructed. What is going on?
Edit: And here they show QC testing just as I would do it but they have a POSITIVE charging wire clamped onto the P-??? What is going on here?
https://www.aliexpress.com/item/Wat...orw7fjQ7g2ey5EHdgAcaArsUEALw_wcB&gclsrc=aw.ds
https://vruzend.co.uk/products/4s-1...-li-charger-balance-polymer-lipo-60a-bms-cell
They had good reviews, I dont know whats going on. Im afraid to solder anything now lol. Is there some way to test the BMS? It wouldnt charge, and the voltage from the P-/P+ was lower than the pack voltage. Measured directly, the pack is at 50V, I get 46V from the plug. Plus, it wont charge.
I was told that I could plug it in and actually measure the voltage on the balance leads, see it increase as I moved down the red charging wires coming from the 14 pin molex plug, but that doesnt work. The 72V version is having the same problem.
Do these BMS units just suck? I wired them up just as the diagram instructed. What is going on?
Edit: And here they show QC testing just as I would do it but they have a POSITIVE charging wire clamped onto the P-??? What is going on here?
https://www.aliexpress.com/item/Wat...orw7fjQ7g2ey5EHdgAcaArsUEALw_wcB&gclsrc=aw.ds