pianotuna wrote:
If you know how many amp-hours you have consumed, then charge long enough to replace that number. If they are flooded, check with a hydrometer. If AGM then 0.5 amps per 100 amp-hours of capacity.
Right, so if you have to spot-check anyway to know if your timer was timed right, then why bother with the timer?
A timer is good if you are going to overcharge a little while you are away and want it to stop before anything bad happens. That assumes you know how long to set it for so it will go past fully charged.
A timer is useless if you set it for when the batts are not fully charged yet.
Solar works because night follows day, and assumes you will not be seriously overcharged before dark. Actually, you will be lucky if you get anywhere near being fully charged before dark while camping, with the RV always drawing some amps worth.
You could set your timer close to just right after doing it the hard way by being there a few times. You then know about how long it should take from whatever SOC you start at.