[The_bluester (Paul)]

The SLA is only connected up when in use, actually the original charger that came with it (The battery was salvaged from a jump start pack) was a basic 12 (13.8 odd) wall wart adapter, or charge straight from the car via a lighter socket.

Before astro uses the SLA is charged on a proper 3 stage charger so the 13.8V supply is basically only float charging it in use. When I finally manage an obs I will probably use a standard lead acid instead, floating on the 12V supply.

Regards how much current is drawn, I have not actually measure the AZEQ but I just used 4A as a worst case maximum figure to ensure I would have plenty of spare capacity in the DC supply before I bought it.