Power consumption in Van

[laughto]

If I have 2 x 100Ah batteries in my Van (total 200 Ah) and I draw a constant 5A, roughly how long should my batteries remain use able? I am sure it is not as simple as 200/5=40 hours, or is it?

[weeds]

Umm others will be along I'm sure......

I try and. It go below 50% SoC which is around 12v, fully charged should be 12.6v

In your setup that would be 20hrs with nothing going in.

[BONZER]

you only really have 50% of your batteries as useful before the beer stops getting cold. If you really want to prolong the life of your batteries get 2x100w thin film solar panels and a regulator and keep the batteries up to full charge during the day and saved for the 12-14 hours of night. Next day up comes the sun and the cycle goes on. Cost should be around $450, much less than your batteries will cost to replace when they expire.
Hope this is helpful.
John

[Blknight.aus]

If I have 2 x 100Ah batteries in my Van (total 200 Ah) and I draw a constant 5A, roughly how long should my batteries remain use able? I am sure it is not as simple as 200/5=40 hours, or is it?


its exactly that simple... BUT... its not.

on the face of it if you have perfect conditions, and perfect charging, and no losses and your batteries dont suffer degredation then yes. But you dont have that. it also depends on how your Ah rating was arrived at. if your batteries are rated for 100Ah with a nominal 5a draw as the load then yes you get 20 hours out of each battery.

back to the real world

work on 50% capacity as previously mentioned to get the best longevity out of your batteries and to give yourself a reserve capacity. You'll question it at first when your voltages remain higher than the 50% mark but by year 2 or 3 when your original batteries are still working within the reduced life number as opposed to the guy whose on his second or 3rd set of batteries and has been drawing them to the limits it'll make more sense.