XFYBZN 4S Li-ion Lipo Lifepo4 LFP Lithium Battery Active Equalizer Balancer BMS 1.2A Balance Energy Transfer Board Inductance Balancing Protection PCB

I needed to "repurpose" some older LFP cells and the BMS by itself didn't keep the "cheap" cells in balance. Added this balancer to an 8S1P pack of 32700 cells. Basically added it on top of the BMS; works just fine. Sense wires for each cell are long enough and different colors to help ensure you get them connected in the right order.

I wired it up and plugged it in, I’m always skeptical of products so I monitored voltages of a pack already balanced. It immediately pulled voltage out of 1-3 cells and started forcing cell 4 up in voltage. Junk do not buy

So if you have a string of eight cells and you're buying a balancer, the expectation is every cell in the pack will be at a very similar voltage than the rest of the cells in the pack. That's not what this does. In fact, the first cell relative to the second cell could be 0.1 volts lower and the second cell relative to the third cell could be 0.1v lower and so on all the way to the last cell. A pack that reads 2.79,2.88,2.97,3.06,3.15,3.24,3.33,3.42 won't trigger this balancer to even turn on! This balancer would work okay on a well-balanced pack to maintain it, but it absolutely will not balance a very out of balance pack. I will be returning it.Update: after extensive experimentation and reading the data sheet for the IC that controls the voltage threshold for starting and stopping balancing, it became clear to me that this IC was developed and optimized for lithium ion, not lithium iron phosphate. As such, the triggering mechanism works better at slightly elevated voltages. Setting my BMS to terminate charge when the first cell hits 3.8 volts did two things. 1. It caused larger voltage differentials in my 8s pack. 2. It caused the IC in this balancer to trigger reliably at the end of charge and start balancing. The result is much more aggressive balancing and better performance overall. So, if you want this to work, try slightly overcharging your lithium iron phosphate cells to 3.8v for aggressive balancing then set your cell cut off back down to 3.60 volts after the pack is balanced for longevity.I don't see this as a terrible thing, considering the absolute Max voltage on lithium iron phosphate is 4.2 volts and the cell only stays at 3.8 volts for perhaps one to two minutes at the end of charge.I am adjusting my rating and considering keeping this. The chip manufacturer should consider altering the detection algorithm and threshold so it works better for lithium iron phosphate at the lower cell voltages. Also worth mentioning, this chip supports two amps. I don't know why they didn't enable it. Perhaps heat dissipation or reliability.

My dad made me buy it .

There's no directions pretty sure it was hooked up correctly but no idea because there's no directions light turns red when plugged in then shuts off and no lights what's that mean ? It's charged it's hooked up wrong no idea