OK here is chart kind of...
To power the truck and a fully charged truck battery required about 2 amps from the alternator.
I drained camper batterys down to 12.3 volts
5pm start
amps 57
volts at camper batterys 13.99
alt temp 148f
5:20
amps 22.4
volts at camper batterys 13.93
alt temp 188f
5:40
amps 19.5
volts at camper batterys 14.05
alt temp 187f
6:00
amps 13.4
volts at camper batterys 14.02
alt temp 176f
6:20
amps 11.3
volts at camper batterys 14.09
alt temp 171f
6:40
amps 8
volts at camper batterys 14.20
alt temp 159f
7:00
amps 5.8
volts at camper batterys 14.22
alt temp 160f
7:20
amps 4.9
volts at camper batterys 14.33
alt temp 155f
7:40
amps 4
volts at camper batterys 14.34
alt temp 154f
Note: I could have probably stopped here as batterys were most likely charged.
8:00
amps 3.2
volts at camper batterys 14.34
alt temp 154f
9:00
amps 2.7
volts at camper batterys 14.39
alt temp 154f
9:10
After running the furnace for 10 minutes to take off the surface charge, I took a final volt reading.
12.85 volts at battery.
In summary without using amp meter or anything else when camping I will charge until volts get up to the 14.3 mark and stop there more or less... This will be with my volt meter I have in the camper..
Although I always carry my multimeter with me and the hydrometer...
