I am building a series of 13s LiPo battery packs, each with a BMS with B- P- and C-. They are to be charged with a regulated source from a PV array. I know this likely depends on the specific BMS, but is it a good idea to charge the batteries from the positive terminal through to C- whilst current is being drawn through P-?

It's a 13s pack, so 48v nominal, and I'm using these BMS boards. The C- is the return path for charge current, other end goes directly to the battery + terminal.


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  • \$\begingroup\$ I know what B- and P- are. What is C-? Also can you provide a link to a BMS that you are considering using? Don't answer in the comments. Add the information to your question and then I will delete this comment. \$\endgroup\$
    – mkeith
    Feb 7, 2021 at 18:29
  • \$\begingroup\$ Simultaneous +/- current to battery reduces the charge rate so it is unwise to do this during CV longer than normal as duration spent above 4V accelerates aging. \$\endgroup\$ Feb 7, 2021 at 21:43
  • \$\begingroup\$ Please provide a link to the manufacturer's datasheet and/or user manual. A link to ebay is not generally helpful. \$\endgroup\$ Feb 8, 2021 at 21:32
  • \$\begingroup\$ Do you think I'd be here if the manufacturers of cheap Chinese boards were into providing datasheets? It's a generic question, posting when you have nothing to contribute is not generally helpful. \$\endgroup\$ Feb 10, 2021 at 10:43

1 Answer 1


I've decided to use a manual switch to either charge the batteries or put the PV array in parallel with the battery output. The idea being to take as much load off the batteries when the system is drawing current. I would do this after the batteries have been charged of course, to around 80% capacity to prolong life. BMS boards will have a maximum charge current as well as a maximum draw current so keep that in mind if anyone has a similar project.


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