Well just spent some money in Maplin getting some new test leads and we have a current draw of 0.46 amps after the car sleeps. Just waiting for it to go to sleep again before I pull the wire on the alarm siren to see if it drops.

Lucky for me my DMM has a 20A rating for DC amps as it draws more than 12 when you connect the battery for a short period before dropping back to 8 and then 0.46.

Well, I've had to abort the playing around. I've run the battery right down waiting for the car to sleep. I did not even get to the full 15mins twice before things got shutdown.

However once the battery manager has killed everything because the battery is low the current flow drops right back to almost nothing, between 0.03A and 0.09A.

I think I need a new battery, this one despite the car being used today is just not right. Halfords have a 110ah HB020 Yuasa Silver battery listed as compatible, but its £159. May just buy it anyway, so I can at least continue testing to check the alarm siren, still not got that far.

See image, bcm had done its thing by this point. I need to work out why 0.4amps, it could still be the alarm siren but cannot confirm that yet.

Have you a ECP near by? Bosch S5 110Ah is £139.20, maybe a little less with some haggling.

http://www.eurocarparts.com/ecp/p/ac...008&0&cc5_1026

Or the Varta 110Ah is low as £95 online, ebay etc.

I can lend you conductance battery tester for the cost of postage if you want to test old battery before buying new or I can test it for you if you coming in Northampton / Kettering direction.

ECP just round the corner from where I am in Hertfordshire, and they have that battery in stock.

I am still determined to locate the source of that 0.4A drain, although I suspect the car may have always had it based on the fact the battery had always dropped to 50% if left for 4 or 5 days.

I guess that over a period of time the battery has deteriorated and I guess that in 18 months I'll be going through the same thing.

Very puzzling, car was ok last night. Battery at 100 this morning and after car sleeps current draw is tiny. Alarm is still connected.

If the power management module is playing up and you code a new battery in then it will normally work fine for quite a while before playing up again so as I have said before it may be that your battery management module is intermittently playing up. if all is well for a while now and then it starts to do it again then I would replace the BMM.

The D3 electrics are certainly a challenge.

There are so many different types of BMM, with the negative terminal in different places. I'd also need to try and get the newest one possible to try and avoid getting a used duff one, or a used one with the old firmware that would need updating.

One other possibility, yesterday before I aborted the current test due to low battery I was getting ready to disconnect the alarm siren. I had the siren unbolted, and it was laying face up with the power connection visible to disconnect for around 15mins. Since putting it all back together everything seems to have been fine.

I keep going round the same circle, battery, alarm siren, heater resistor, BMM. Could be any of these acting up.

This is the current BMM

I would hold off buying a new battery for now. Certainly pick up a replacement BMM. This newer revision from ebay seems good value, assuming it's undamaged, the seller will accept returns.
http://www.ebay.co.uk/itm/161819882804
It is a different shape to our existing modules, but the top left mounting is in the same location so I hope there's no complications with fitting.

One thing I noticed from your VCDS scan is that the Shop# is different on your BMM module compared to the majority of your other modules. So maybe the previous owner had problems and had it changed.