Follow your consumption with a battery monitor, it saves you a lot of trouble. Incl. bluetooth and display of voltage on start battery.
12/24V Professional battery monitor, comes complete with round and square look, plug and play installation for battery bank up to 10,000 Amp hours and continuous consumption up to 500 Amp. Instant consumption, total consumption, remaining capacity, built-in alarm on all parameters. And with socket for external alarm.