Anyway to check if BMS has separate port for charging?

[Wullen]

A bought a new battery from PSWpower and I would like to charge the battery from a batterymount mounted on the wall connected to a charger. So I can easily just put the battery on the wall when I come home and it starts to charge. I opened the to check the BMS, but it was under so many layers of paper and plastic, I didnt want to tear it all up.

So anyway is there a simple way to check if the battery uses a common charging port or not with a multimeter? I guess the battery charges thrue battery terminal in both cases? The off switch on the battery turns of the BMS?

Maybe I could quickly test the fully charged battery with a charger thats put out 55-56 volt, and see if the battery refuses to charge thru the battery terminal? As it would still keep charing then if it does not have a common port on the BMS?

 

[fechter]

Unless you take it apart enough to see the connections, I can't think of an easy way to tell. Intentionally tripping the BMS would work and you could do it by either over charging or over discharging and measuring the voltages on the charge and discharge ports. Common port they will always read the same. If the BMS has a temperature sensor you can see, you could use a heat gun and try to trip it.

 

[amberwolf]

So anyway is there a simple way to check if the battery uses a common charging port or not with a multimeter? I guess the battery charges thrue battery terminal in both cases? The off switch on the battery turns of the BMS?

If there is only one connection to the battery on the case, just the main + and -, and no separate charging connection, it would almost certainly only have one BMS port as well, if it is correctly wired. It could be poorly (unsafely) designed and built, of course.

To safely use separate C&D ports it has to have separate wiring to separate connectors. If the BMS has separate C&D ports, wiring them together to a single connector means that there is no way for either port to ever shut off power to / from the battery, because the intrinsic diodes in the FETs would always let current flow in (thru the discahrge port) and out (thru the charge port).


If it has a separate charge connector, it probably has separate ports, and you should use the charge connector to do any charging.

 

[Wullen]

Unless you take it apart enough to see the connections, I can't think of an easy way to tell. Intentionally tripping the BMS would work and you could do it by either over charging or over discharging and measuring the voltages on the charge and discharge ports. Common port they will always read the same. If the BMS has a temperature sensor you can see, you could use a heat gun and try to trip it.

Yes. But would it not be the case that if the battery is fully charged, and I connect 56v to 13s battery thru the terminal, the BMS would refuse charge if it a commonport system? The battery will not draw any power from the charger so to say. (I have a power meter on the charger so I can see it directly if the battery draws power from the charger)

 

[fechter]

Yes. 56v should be enough to trip the BMS and it should stop the charging current. Once this happens, you can try charging through the discharge port and see if it takes any current (but don't do it for long).

Does the pack have a separate pair of wires or connectors for charging and discharging?