General question, I'm learning as I go ahead, and the more I progress the more I realise I don't know anything :-)
I have a small solar setup and my battery is a Victron Deep Cycle AGM 60Ah.
It is connected to a SmartSolar 75|10 and I monitor it via a SmartShunt.
The battery is used to power LED lights and give power to a couple of small electrical loads. Everything is connected to the load output of the charge controller, works perfectly fine. With the lights on I draw around 24W.
Battery charges correctly, everything is fine.
I also have (wired directly to the battery/shunt) a 1000W inverter.
It doesn't get used much, and generally with loads of about 50/150W for 10/15 minutes maximum.
So far so good.
I sometimes want to connect a much bigger load (air compressor). It runs for less than a minute generally, unless it is fully empty, in which case it will run for a couple of minutes, (but this case will happen less than once a month).
The compressor is rated at 700W. When used, the SmartShunt measures about 900W (and a healthy 86A) but the battery voltage drops down to 10.5 under that load.
The SmartShunt indicates about 20 minutes remaining energy (at 50% SoC) under that load.
I used it a couple of times to test it. Battery SoC went down about 10% (as indicated in the app), charged happily in the next day or so.
Questions are:
– how much would be an acceptable voltage drop under an heavy load for that AGM battery (cannot find data online)?
– any pointers on how to properly calculate battery capacity to run something like that?
Thanks in advance.
