AGM battery Lowest voltage

Hi guys
I recently installed my first on-off grid solar system in my apartment, it has been working great altho I think I could optimize it a bit for power savings.
My setup is as follows:
4KvA Axpert inverter
12 - 12v AGM batteries (3 series of 48v)
15 - 300W solar panels
My question for now is how low can I discharge my batteries before switching to the grid.
I currently have it set to 47v on the inverter and once it switches to the grid it bounces back to 48v when the load is off.
Can i go lower than that? or is that the sweet spot
Thanks all
I recently installed my first on-off grid solar system in my apartment, it has been working great altho I think I could optimize it a bit for power savings.
My setup is as follows:
4KvA Axpert inverter
12 - 12v AGM batteries (3 series of 48v)
15 - 300W solar panels
My question for now is how low can I discharge my batteries before switching to the grid.
I currently have it set to 47v on the inverter and once it switches to the grid it bounces back to 48v when the load is off.
Can i go lower than that? or is that the sweet spot
Thanks all
Comments
Without knowing the battery capacity or loads it is not possible to quote a definitive value, some experimenting to see what the resting voltage is after loads are disconnect would be of more value as this would reveal more accurately the true state of charge.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Each battery has 114aH Capacity and my consumption is pretty steady through the whole day, 1.5Kva (1 small air conditioner some led lighting and a couple of computers/tvs)
currently the resting voltage is sitting at 48v
Thanks
The thing to remember is if they are discharged to this level it's important that they receive a full charge as soon as possible, keeping them in a partial state of charge will lead to sulfation and premature failure. Using batteries is in most cases significantly more expensive than grid power, if the system is a backup UPS type, it makes sense to cycle them due to the fact that if you're not using them, you're loosing them, they do die within a given number of years even if never cycled.
Being unsure what you are attempting to achieve, using the solar array to support loads as much as possible, would make the most sense, this is a ballancing act. Speaking of ballancing acts, having 3 parallel strings of batteries can lead to charging/dischargeing imbalances especially if connected incorrectly, having a DC clamp on ammeter would be a valuable tool to have.
One consideration would be to cycle the batteries every second day this would allow them to recover fully at least 50% of the time, just a thought as there is limited information.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Turns out my darned router used significant energy. It sends power to the "parabolic" dish on the roof. Ever heard of that?
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
Interesting thing about the thousands of hobbies, professions and interests. The pros that are carving out a living in that niche usually have a few hundred must do's in order to stay alive. Because nobody has anything else going on. Yea - I know already. Everything will soon go up in a gigantic ball of flame!
We recently had a pro lecturing that we simply can't have batteries in our house. Did he also exclude the garage? Because he had been in several structures with hydrogen gas. How had he managed to defeat the odds and stay alive we may ask.
If I fine tuned my settings every time it was suggested, I would probably have moved my bed next to the controller for convenience. And would be able to program the CC blindfolded.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,