BMS recommendation

Hi for all,
I’m searching a reliable and safe bms. I find this on ebay: https://www.ebay.com/itm/8S-20S-Smart-lithium-Lipo-Lifepo4-LTO-Battery-BMS-Protection-Board-Bluetooth-APP/312949237002?_trksid=p2504926.m5232.l9681

Has someone practical info about this bms? Maybe someone who use this on his eppg?
Thanks a lot,
Roland

Does it need to be smart?

These are good

hi,
it is a good think if it is smart. On your pic i see 30amp on the label. I need 14s and 200…300amp to be on the safe side.

Oh sorry. Using this for charging only. I hate using the fets for discharge.

Let your motor controller shunts communicate the limit current.

This 24s works on 20s etc.

This is a good idea what you are using! Honestly, I wouldnt like to discharge so high current trough the bms. but for charging would be great to have one. How do you wired the bms only for charging? Some advice would be nice, many thanks!

for charging, just connect as normal. for discharging, bypass the BMS directly. have two connectors.

Ok, but would be nice to see a practical solution for this. I find many sketches on google. But those are only sketches.

I don’t think you need a diagram for this. literally a cable from the positive and a cable from the negative. like connecting without a BMS. the second set of cable use the BMS diagram. you can use a completely separate set of cables. I think most BMS’ disconnect on the negative like this one:

Hi, another question after i searched the web for bms /only charging and by discharge bypassed/. For example this:


It looks nice but i’m concerned a bit. They give for 14s 58.8volt thats ok. But in the description is overcharge voltage 4.25 volt. Is this ok? What is the meaning of this? As far as i know li-ion battery cell charged voltage is 4.2 volt. Why is than set the overcharge set to 4.25 volt? Can’t this harm for the cell?

By over charging it by .05 volts it will decrease the over all life of the cells by about 50%.

https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries
(this is a very good article that I think anyone with lithium batteries should read)

It will also increase the risk of internal short circuits and fires. If it will really over charge the batteries I wouldn’t get it.

if $ is less of a concern, go with one which you can customize? you need a contactor for the amps. https://www.energusps.com/shop/product/tiny-bms-s516-150a-750a-36

I have a 300a bms that I used with my Vruzend Li-ion pack that is no more. The bms worked super well with custom settings via Bluetooth on android phone. Pm me if your interested. It’s just collecting dust now on my shelf.