Lurkin
100 kW
I've bought a Chinese BMS to play with until my frame issues are sorted out. Given that there's little known of its origin or capability, it makes sense to test it silly before committing it to a decent sized pack.
I've been looking on here (yes, using the search function) for a simple 'how to' for BMS feature testing. I'm struggling to find one. Yes, there are long and complex threads on here involving BMS, but I think a quick and dirty how to would be of great value to people new to BMS. I'm thinking tools, tests, techniques, things to watch out for, how not to burn your house down.
Features of the BMS in question:-
- 13S 48v with balance function for 3.7v lithium ion batteries
- Continuous working current: 40a
- Maximum discharge protection circuit 100a
- Dissipation Power: less than 20uA
Tables aren't posting properly from the ad. The BMS is this one here: http://www.aliexpress.com/item/Free-Shipping-48V-40A-BMS-13S-48V-54-6V-li-ion-battery-BMS-PCM-40A-continuous/32283657890.html
The plan to so far:
- obtain 13x junk 18650s and individual cell holders
- attach cell log 8s
- apply a small current at 54.6v to charge, watch and see what happens
Questions:
- Can I do this with a power supply (with variable voltage and current so I can control it) rather than an actual charger and switch it off when the cells are at 4.2v?
- If so, how does this work with the balancing cycle? do I need to reduce the current further but maintain the voltage?
- what am I missing here?
If I can get some help figuring this out, I intend to start buying cheap BMS and testing them, posting up the data and making an entry into the wiki with the testing plan for everyone's benefit to be able to get affordable, some what tested BMS.
I've been looking on here (yes, using the search function) for a simple 'how to' for BMS feature testing. I'm struggling to find one. Yes, there are long and complex threads on here involving BMS, but I think a quick and dirty how to would be of great value to people new to BMS. I'm thinking tools, tests, techniques, things to watch out for, how not to burn your house down.
Features of the BMS in question:-
- 13S 48v with balance function for 3.7v lithium ion batteries
- Continuous working current: 40a
- Maximum discharge protection circuit 100a
- Dissipation Power: less than 20uA
Tables aren't posting properly from the ad. The BMS is this one here: http://www.aliexpress.com/item/Free-Shipping-48V-40A-BMS-13S-48V-54-6V-li-ion-battery-BMS-PCM-40A-continuous/32283657890.html
The plan to so far:
- obtain 13x junk 18650s and individual cell holders
- attach cell log 8s
- apply a small current at 54.6v to charge, watch and see what happens
Questions:
- Can I do this with a power supply (with variable voltage and current so I can control it) rather than an actual charger and switch it off when the cells are at 4.2v?
- If so, how does this work with the balancing cycle? do I need to reduce the current further but maintain the voltage?
- what am I missing here?
If I can get some help figuring this out, I intend to start buying cheap BMS and testing them, posting up the data and making an entry into the wiki with the testing plan for everyone's benefit to be able to get affordable, some what tested BMS.