We have a 12v / 415AH off grid setup with solar (1KW + Victron MPPT 150/50). We are not getting enough sun (barely any actually). So we are running a small 2KW generator for about 10 hours with a Victron 30Amp charger from time to time to try and fully charge the batteries. However for some reason we never seem to be getting the charge up to 13v (or even above our 70% / 12.3v level). You can see from the data when we run the charge (5 July, 12 July, 19 July) the min voltage is stepping up but it's not getting to where it should be (running 10 hours at 30amps should give us 300 amps which should be well north of 12v. We are not running the power on the charging days so we cant figure out what's going on. Any ideas?