[Goran]

for comparison, my current D2 S8 draws around 0.18A (using Maplin clamp Amp meter) and has very few options, my previous D2 S8 drew over 0.2A

A simple calculation, 0.1A over 24 hours is 2.4Ah capacity per day
If you have the standard 85Ah battery, and if it was fully charged, at your current rate of discharge it would take roughly 18 days to drain down to 50%
If your reading is correct, I suspect your battery is either discharged, or heavily sulfated and wont hold a charge.

Check your open circuit battery voltage. When fully charged, check its open circuit voltage, then leave disconnected for 24 hours and check voltage again, or connect a 12V bulb or something that draws a decent current accross the battery briefly, leave to rest for 10mins and check the voltage again. If the open circuit voltage after standing or brief load drops significantly from fully charged voltage, lets say from 12.7V to 12.3V or less, then your battery is heavily sulfated and hasn't got much of the original capacity remaining. On the web there are articles which reference open circuit voltage to state of charge. From memory, 12.0V or below is pretty much fully discharged.