V6 will not crank after flat battery

[Mrs Feynmans Bongos]

Unfortunately a week later, my V6 would not start again for its weekly commute

But at least this time I had clicks (unlike when main fuse blew), I later measured Battery @11.2V.
After trickling all night it starts again, but I'm now worried about (some combination of):
a) did my new-ish heavy-duty Varta suffer, on recent draining to 5V;
b) did Varta charge fully, on 40mile round-trip commute?
c) do I still have some parasitic drain? (even after turning OFF interior light )

With Engine running (20 mins after charger->OFF), I raised the AFT, toggled upstairs light, Battery showed 14.53V. Does that show Alternator is ok?
Then 12.94V with Ignition OFF, 12.75V with Key at "II.On" (dashboard alight), 12.33V with Key at "II" plus Headlights ON.
With Key still at "II.On" and Headlights OFF, Battery seemed stable at 12.68V, so I started PULLING FUSES (?? if voltage stepped UP, I'd have found a drain ??)
Pulling/replacing single fuses in turn, Battery went from 12.68 to 12.62V monotonically working my way across all 21 Cabin/X03 fuses, then all 10 X02 Fuses.
That all seemed healthy to me, ie nothing sudden but visible decline expected due to Key at "II.On" keeping the ?Solenoid energised. Is that correct?

At that point, me and the lad came inside to think and get FURYous

Ideas so far:

• Is my method above ok, trying to identify a draining fuse circuit? Especially Key at "II.On". Or better putting my DMM probes in fuse holes? (if it will take 1A)
  
• We have a new memory foam mattress upstairs, very comfy, using it on top of older 1" thin one, now ~3" total.
  Is this too thick, ie risks switching upstairs light when AFT is closed? How much clearance is there up there, with AFT closed?
• My mate says auto interior lights can develop a draining short, if panel they are mounted on gets deformed/"pushed". Am I deforming AFT or ceiling panels?
• Is it sufficient just to pull connector at back of (redundant Japanese) ETC unit?

PS Best wishes to Cuch, he is more than half-way there, finding the drain causing his "Utterly Flat Batteries"

[g8dhe]

A 40 mile round trip assuming you had to restart after 20 miles would not have have fully charged a low or flat battery, it would probably just about cover putting back in the charge you used to start if it was from cold each time, in rough terms.

The voltages you quote sound about right;
14+ volts during charging,
12.6 to 12 .8 volts standing,
below 11 volts the battery is pretty flat.

Trying to ascertain what is causing the battery to go flat by just watching the voltage is not really going to work over a short time period un;ess the current being drawn is excessive ....

The only real way is measure the current and identify which fuse circuits are causing the exessive draw from the battery, and then to investigate just what device is drawing the current from that circuit.

[Bob]

I'm pretty sure the AFT light won't come on when the roof is down.

There's a switch to prevent you leaving it on by mistake so you could raise roof, switch on light, lower roof and see if it goes out.

[g8dhe]

That's right the AFT switches the roof light OFF as it comes down its built into the limit switches for just that purpose.