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So I've got AW1 1.0 TSI 70kw/95h model. Car is now 5 years old. I've got a Topdon BT100 battery tester and I'm not able to test the state of the battery without removing the whole plus connection clamp/box since I can't see the battery specs to test it correctly. Will disconnecting the battery result in error codes from the car?

Only some codes about the battery being disconnected. Nothing permanent, unless you keep it off for days at end.

Why not just assume that it is a 320A DIN and use that value when testing it?

iichel wrote: Fri Apr 14, 2023 1:38 pm Only some codes about the battery being disconnected. Nothing permanent, unless you keep it off for days at end.

Awesome, thank you!

RUM4MO wrote: Fri Apr 14, 2023 11:11 pm Why not just assume that it is a 320A DIN and use that value when testing it?

Because the reading will be incorrect, I assume anyway.

you could get an OBD lead specifically made t keep the Memory alive/powered

you need a little 12v power supply for it.. I us my emergency jump starter for that.

Luka wrote: Sun Apr 16, 2023 8:06 pm

iichel wrote: Fri Apr 14, 2023 1:38 pm Only some codes about the battery being disconnected. Nothing permanent, unless you keep it off for days at end.

Awesome, thank you!

RUM4MO wrote: Fri Apr 14, 2023 11:11 pm Why not just assume that it is a 320A DIN and use that value when testing it?

Because the reading will be incorrect, I assume anyway.

Surely all your battery analyser/tester will or can test for is the voltage across the terminals and the theoretical CCA DIN or EN, new batteries when charged and before being connected up into a car circuit will give a crazy high CCA reading, both my new batteries, AGMs tested as being at least 10% over the value printed on the battery.

Any time I've tested/checked car batteries, I've accepted the value being given while the battery is still connected to the car, charged up then left for 8 hours with the ignition etc off, so all controllers in their sleeping mode, ie minimum current draw.

Edit:- actually the 760A CCA (EN) still not used AGM Bosch, tested as 900A CCA (EN) when first bought and not fitted to a car, so the "out of circuit" test result should give you a falsely high value - or at least a value that does not reflect the useful life remaining in that used battery.

grazuncle2 wrote: Tue Apr 18, 2023 5:28 pm you could get an OBD lead specifically made t keep the Memory alive/powered

you need a little 12v power supply for it.. I us my emergency jump starter for that.

I agree, so easy and obvious especially if you are the sort of person that spends money on a battery analyser - well I have what you suggested AND a CTEK battery analyser.

I've also got a CTEK 12V DC support/maintenance unit, but save that for other times.