Recommended quality programmable BMS for 52V pack?

[skestans]

Hello

I’ve used EM3ev batteries for a few years, but both BMS failed on them while they were only lightly used. They have all lights on, don’t charge, don’t discharge, don’t show on Bluetooth anymore. Every once in a while they’ll turn on and charge/discharge but not show on BT, and you never know when turning it on whether it’ll fail with all lights on or charge/discharge without BT.

I’m surprised they’d both fail after a few years and with light use so I’m not super keen on replacing them with the same part that will likely fail again after a few years. Especially that shipping is ridiculously expensive (more than the part is worth)

What other alternatives are there that are similar or better in quality than the D-Power origin BMS?

Batteries are 52V Samsung 35E cells 14S5P, 25A continuous 34A max burst.

BMS has Bluetooth monitoring, 2x temperature sensors, and is programmable. It also balances cells when charging and when over 50% charge.

Any quality recommendations people here could vouch for? I’m in the EU.

Thanks and happy holidays!

 

[j bjork]

I think I would go for the small JBD 7-14s bms. Cheap, small and seems to be decent quality.
But are you sure it is the bms:es? Have you checked cell voltages?

 

[eee291]

I can also vouch for the quality of JBD BMS.

 

[skestans]

I think I would go for the small JBD 7-14s bms. Cheap, small and seems to be decent quality.
But are you sure it is the bms:es? Have you checked cell voltages?

Yes, the cells were fine when the BMS worked. Both failed the same way.

 

[skestans]

I can also vouch for the quality of JBD BMS.

Where do you buy it?

 

[eee291]

AliExpress, jbdbms.com, Amazon, Overkill solar etc.

 

[skestans]

AliExpress, jbdbms.com, Amazon, Overkill solar etc.

Ok thanks. They don’t seem to have a connection for temperature sensors though, do they?

 

[j bjork]

Ok thanks. They don’t seem to have a connection for temperature sensors though, do they?

They do, but only one.

 

[scianiac]

Yeah JBDs are good but the LTT and JKs also are good and sometimes they have some combination of options or size you need so lots of options. I think LTT uses the same software but the hardware is different which I've found they have some that are smaller or some have more connections.

 

[molin]

Hello

I’ve used EM3ev batteries for a few years, but both BMS failed on them while they were only lightly used. They have all lights on, don’t charge, don’t discharge, don’t show on Bluetooth anymore. Every once in a while they’ll turn on and charge/discharge but not show on BT, and you never know when turning it on whether it’ll fail with all lights on or charge/discharge without BT.

I’m surprised they’d both fail after a few years and with light use so I’m not super keen on replacing them with the same part that will likely fail again after a few years. Especially that shipping is ridiculously expensive (more than the part is worth)

What other alternatives are there that are similar or better in quality than the D-Power origin BMS?

Batteries are 52V Samsung 35E cells 14S5P, 25A continuous 34A max burst.

BMS has Bluetooth monitoring, 2x temperature sensors, and is programmable. It also balances cells when charging and when over 50% charge.

Any quality recommendations people here could vouch for? I’m in the EU.

Thanks and happy holidays!

That does sound frustrating, especially if both packs developed similar issues. If the LEDs stay on but the pack won’t charge or discharge, it sometimes indicates the BMS is stuck in a protection state or the communication module has failed. The fact that Bluetooth disappears also suggests the control board may be crashing or losing power intermittently.

Before replacing the BMS completely, it might be worth checking a couple of things:

• Cell group voltages (to make sure none of the series groups drifted too far apart)
• Temperature sensor connections
• Whether the BMS can be reset by disconnecting the balance connector for a few minutes

If you do end up replacing it, there are a few BMS brands that people here seem to have good experiences with:

• JBD (Jiabaida) – widely used, good Bluetooth app support
• Daly – simple and fairly reliable, though less configurable
• ANT BMS – very feature rich and powerful, but sometimes a bit complex

For a 14S 52V pack with ~25A continuous, a 40A rated BMS would probably give you some margin.

One thing to keep in mind is that many smart BMS units rely heavily on the firmware and communication board, so reliability can vary depending on the version. Sometimes a simpler BMS without too many “smart” features ends up being more robust long-term.

Hopefully someone in the EU can also suggest a good local supplier to avoid the shipping costs.

Many BMS failures we see actually come from the communication or power supply section rather than the MOSFET stage.

 

[skestans]

• JBD (Jiabaida) – widely used, good Bluetooth app support

Thanks for the info.

For now one of the BMS works: turns on charges/discharges, just no BT. I don’t know what else doesn’t work (balancing?)

I’ve looked into JBD, but I don’t know how to adapt it to my pack: the power button and LED meter combo has 7 wires whereas all the other BMS offer just a separate on/off switch and the LED meter is based off the voltage with just a couple wires.

The LED board and connector:




The cells connector:


Two bullet plugs (C- and B-)





The MOSFETs