48v solar Battery low voltage switch

[offgrid Rod]

Hi, I hope someone can help with my offgrid technical issue?

Spec: 3kw panels in series into photonic universe 5kv charger/ inverter. 48v 24kv battery bank, 24x 2v cells.

Issue: when I'm away and there's no sun for a few days, I lose power. As I'm not there to start backup generator.

Solution 1: get a generator with ATS, but this only starts when there is power loss, so heating, alarm and cameras lose power. And once power is restored the generator turns off. I could put a delay relay say for 1-2 hours to get decent charge. But still the issue of losing power in the first place.

 

What I am looking for is a voltage monitor say set to 46v, 47v that'll switch the ATS via the delay relay to start the generator and run for 1-2 hours, so power is not lost. So system is now fully automated.

Is there such a unit on the market, as I can't be the only one with this issue.

Any help would be appreciated.

Cheers.

 

[joth]

What exact make/model of charge controller do you have? It may have built in state of charge monitor, but there's dozens of pages of them on that website.

 

Alternatively you can add a stand alone battery monitor like this that has a relay output that can be configured to flip on when the battery is below a certain SOE and off again when it's above a high threshold. If the generator has a remote start input and also charges the batteries when it's running this should be all you need. 

https://www.photonicuniverse.com/en/catalog/full/505-Victron-500A-12V24V48V-Smart-Battery-Monitor-with-Inbuilt-Bluetooth-BMV-712.html