Adding charger cutoff circuit

[E-HP]

Anybody either modify their generic battery charger or add a circuit to cutoff charging at a chosen voltage? I was thinking about building a circuit, but then found a few like these which might be cheaper than making one (unless I could find parts locally and avoid shipping).

https://www.amazon.com/Ximimark-XH-M604-Battery-Protection-Controller/dp/B07HQ8LLMH/ref=asc_df_B07HQ8LLMH/?tag=hyprod-20&linkCode=df0&hvadid=309768150198&hvpos=1o3&hvnetw=g&hvrand=13376709288029506236&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032086&hvtargid=pla-599144430674&psc=1

I see it's about $5 cheaper on AliExpress (~$7.50 after shipping).

EDIT: It just occurred to me that I could probably just open up the charger and add a switch and a pot to modify the existing circuit to do the same thing. I'm going to take a look.

 

[amberwolf]

FWIW, there's at least one thread about those types of modules, using them with chargers, etc, but I cant' find it with the terms involved in this thread, or anything else I could think of. :/

 

[Drunkskunk]

that BCCM would work for bulk charging batteries just fine. However, if you have a BMS, it's likely going to interrupt the balance cycle, meaning your battery will not be properly balanced, and could lead to destroyed cells. Most BMS need power from the charger to keep in their balance cycle after the charging is over. that BCCM cuts off power instead of holding the power at a lower level.

It would be better to find a way to adjust the peak voltage that the charger puts out. Most are going to have some form of trim circuit even if there isn't a trim pot. Or you can get an adjustable constant currant type power supply.

 

[E-HP]

that BCCM would work for bulk charging batteries just fine. However, if you have a BMS, it's likely going to interrupt the balance cycle, meaning your battery will not be properly balanced, and could lead to destroyed cells. Most BMS need power from the charger to keep in their balance cycle after the charging is over. that BCCM cuts off power instead of holding the power at a lower level.

It would be better to find a way to adjust the peak voltage that the charger puts out. Most are going to have some form of trim circuit even if there isn't a trim pot. Or you can get an adjustable constant currant type power supply.

I was planning on using the unit in between balancing cycles, when I usually charge to 57 volts or so. Inevitably I get around to unplugging the charger late, and end up around 58 volts and have to ride the bike around to get it to 57. If the unit works the way I think it should, it will just shut off the charger, when I would normally unplug it.