Flat Battery Investigations

[Goran]

If its any help I measured my old S8 (FL) current draw with everything shut off, key out, at 0.24A (in the battery compartment, multimeter in series with battery)
Get yourself one of those clamp amp meters so you dont have to keep disconnecting the battery to put a standard multi meter in series. I need to get one too.
http://www.tmart.com/Mastech-Ms2001-...r_p144098.html
(make sure sensitivity is enough for low currents)

If you already measured it to be 0.35A, that shouldn't be high enough to kill a 95Ah fully charged battery in a week.
95x0.8/0.35 = 217hours, or 9 days to go down to 20% capacity.

Although its 0.35A is a bit high, have you run a VCDS auto-scan with everything switched on including the radio? Radio will sometimes only show speaker-to-ground errors if its switched on whilst you scan it.

Also, some cars apparently go into sleep mode 15~20 minutes after the key is out, so may be worthwhile measuring current draw again to see if it reduces.

[notorious]

0.35A is a bit high.

I've got 0.13A total drain at battery terminals. Still too high IMHO. About half of that is stereo one in the boot (car is RNS-E upgraded), the rest is "Yellow 4", plus very minor current in "Brown 1" and in "Brown 3".

I measure at battery terminals. Lock car and wait for 3 minutes when RNS-E goes to sleep.

I'm very interested to know how your "Yellow 4" investigation will finish.

Any 3rd party electrical equipment installed?

I'd like to recommend this battery isolator switch: http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=230825055786
Very convenient to quickly connect/disconnect battery. In disconnected mode just connect tester to measure drain current.

In terms of clamp meter the one that Goran recommend will be too rough to measure mA currents. I'd go for this one: http://astore.amazon.com/m0711-20/detail/B001TCWL1E

http://astore.amazon.com/m0711-20/detail/B001TCWL1E

[Goran]

Sergey is right, go for a better meter. I have been investigating which one to buy, apparently Kewtech and Fluke are amongst the best. Here is a Kewtech meter that looks good available from a UK store.

http://www.tec-supplies.com/products...a+clamp+meter/

or here

http://www.test-meter.co.uk/products...c-clamp-meter/


there is a more expensive one that also measures true rms current for AC circuits, I'm leaning towards it as it could be useful for circuits around the house.

http://www.test-meter.co.uk/products...c-clamp-meter/

here is another UK shop with a wide selection. Watch out for the AC only ones, there is a lot of them and they wont measure DC.

http://www.testermans.co.uk/clamp-meters

[notorious]

I'm looking at this one from FLUKE: http://www.testermans.co.uk/clamp-me...0Clamp%20Meter

Clamp detaches to access awkward places in car.

But currents are measured with accuracy of 1 digit after decimal point...

[Goran]

Originally Posted by notorious

I'm looking at this one from FLUKE: http://www.testermans.co.uk/clamp-me...0Clamp%20Meter

Clamp detaches to access awkward places in car.

But currents are measured with accuracy of 1 digit after decimal point...

Good idea, never thought it may be tricky to get the standard meter into awkward places. Shame about the 0.1A accuracy, but I guess its close enough. Who cares about 0.05A