Have no expertise on this, just common sense.This thread on the CCPs has me wondering again about acceptable (engine-off) draw-down on the double batteries which, although they may be AGM, are nevertheless starter batteries and - as I understand it - prefer an existence where they are fully or nearly fully charged.
I should like to run my fridge off the CCPs rather than from the switched 12-volt outlets (it draws less than 2 amps, and runs about a quarter of the time), but I have no idea of the margin of safety I'd have.
In members' personal experience, what's a reasonably safe limit for drawing down on those AGM starter batteries? By "reasonably safe," I mean that:
1) you can draw down to that level fairly frequently without harming the batteries;
2) there's still plenty of charge left to start the vehicle?
First, I think, it depends on the type of engine. A diesel may need more battery power under certain circumstances.
Your correct, they are starter batteries and as such the answer should be NO. But I don't know, whether AGM's have the same 'starter' or 'deep-cycle' properties as flooded batteries have.
At the very least you should put a meter in between, but common sense tells me that you shouldn't take the risk and not use them as such.