Are relays needed for 8s Chargery BMS ?

[felixdennis]

Hi,

I have 8x 280ah LifePo4 coming to build 24v battery. I got the Chargery BMS and didn't realize I need to use relays to charge/discharge.

Is there any tutorials on this? Are relays required to get this setup going?

 

[Craig]

No tutorials as of yet. Relays most likely are required to use the Chargery. But not always. For instance I can plug the charge lead of the Chargery into my midnite classic SCC and it has a function to stop charging. Some but not many inverters may work similarly.
So if your equipment can turn on and off via a 12v signal from the Chargery it will work without relays. What is your charger and your inverter.
In another thread I am testing some Solid state relay for use with Chargery.

 

[felixdennis]

Thanks Craig. I'm thinking about using the MPP all-in-one charger/inverter.

Will's idea of using SSR to control inverter makes sense here:

My question is how to shut off solar charger if battery is charged etc. What setup do you recommend for this situation?

 

[Steve_S]

The Chargery uses the relays to stop Charge / Discharge when the conditions require it, such as Over Voltage, Under Voltage, Temperature out of specified range and so on. Without the Relays the BMS cannot control input / output, it then becomes an over glorified & very expensive balancer.

We are presently poking around with Solid State Relays & Energy Saving Contactors which are far more power frugal than the standard relay/contactors that Chargery Supplies. I am actually rewriting (anglicizing & clarifying) the darn thing, sometime next week I'll have the drafts up to Chargery for them to finalize. There has been a lot of furtling around with the Relays by many of us and some of us just have to find a better solution for the different use cases.