Two charges one battery bank grid tie

[shavermcspud]

Question on behalf of a friend, one that I don't have the answer to, one grid tied Solis 6kW hybrid inverter, connected to 32kWh of DIY LFP 48v with a seplos 200amp BMS with can coms all working, if they were to introduce a secondary charger (non PV) that outputs a constant 750Watts from a water stream turbine to the same battery pack via the BMS, what would happen, my guess is the pack would charge up along side the PV charging from the GT inverter, but what would happen during nightfall when no PV and the house load exceeds the output of the water stream generation, would the battery also supply in addition to the second charger powered by the water stream turbine? If the battery was full would the second charger be backfed and blow up? So many questions.

 

[hwy17]

It should all work. The hydro should have the necessary logic to back off the charge at the correct voltage in order to not overcharge the battery, and it should be able to withstand overvoltage, i.e. if it is outputting 54v and battery is at 58v.

These are not guaranteed functions of any hydro setup so they should be confirmed in the design phase, but they are standard functions of a good one.

Solar hardware is very refined compared to the array of hydro stuff. You buy a solar charge controller and you can be sure it has all these functions and protections. There are many hacked together hydro plans so a lot more research needs to be done a lot more carefully.

I would probably gravitate towards a hydro design of higher voltage fed through a Midnite, rather than a raw 48v setup. The midnite guarantees you a predictable set of features and protection.

 

[houseofancients]

Question on behalf of a friend, one that I don't have the answer to, one grid tied Solis 6kW hybrid inverter, connected to 32kWh of DIY LFP 48v with a seplos 200amp BMS with can coms all working, if they were to introduce a secondary charger (non PV) that outputs a constant 750Watts from a water stream turbine to the same battery pack via the BMS, what would happen, my guess is the pack would charge up along side the PV charging from the GT inverter, but what would happen during nightfall when no PV and the house load exceeds the output of the water stream generation, would the battery also supply in addition to the second charger powered by the water stream turbine? If the battery was full would the second charger be backfed and blow up? So many questions.

This should work without issue..
I would however set the non pv charge to stop charging at a lower voltage, as it probably won't have comms, and will not know when the BMS tells the Solis to slow down charging when approaching 100%

 

[shavermcspud]

Thanks for the replies, i will pass this info on and report back what happens.