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End of January 2019 when I took the car for MoT the battery failed. 5 miles earlier it started the car without much problem - bit sluggish maybe, but started. Parked at the testing station, had a quick chat with Our Steve then went to move the car onto the ramps - dead as a doornail so went along the street to a factors, bought a new battery and fitted it while a jumper pack was connected hoping that would get me around having to code it, which seemed to work.
Doing the oil seal and turbos later that year meant I didn't use the car much while Covid lock downs and retirement mean that it's been the same this year so from time to time I've charged the battery. About a month ago when I arrived home on foot one night, as I passed the car I noticed that the dash warning lights were illuminated so got the key and found the car wouldn't respond. As it was rather late and I didn't want to disturb my neighbours with the alarm I left it until the next day - lights were still on but the alarm didn't start sounding until I connected a charger. Since then the battery charge isn't lasting long - maybe 3 days. After a charging session on Friday of last week, today there was enough charge to open keyless but not enough to start the car so I'm wondering if the low charge logic (assuming there is some) has got it's knickers in a twist.
Wonderful. Ah, but the new battery had a 5year/60K mile warranty which is good.
Except that somebody has lost the receipt haven't I.....

Wondering if removing and fully charging the battery then refitting it with a changed the coded serial number would do any good.

I bought my car 4 months ago and it had a new battery fitted just before I purchased it, I doubt if it was coded.

It has always turned over fairly slowly when starting and if I'm working on it without a charger connected would come up with "low battery" fairly quickly. I fitted a P3 meter which included a voltmeter and the charging voltage never went above 13.2 Volts. I tested the battery and it was all good.

Last week I changed the battery serial no. Using VCDS (its a Yuasa battery so can't be coded accurately) and the car now runs at 13.9 to 14.1V and turns over much quicker so may well fix your problem too.

The car has a monitoring system which tracks the condition of the battery.

If you don't recode then the car will think it's still the old battery and charge etc accordingly.

That's my understanding.

Wonder if the monitoring system is blocking my charger? Okay, later in the week I'll go ahead take the battery off, fully charge it then refit it with a changed number. Can't see that it'll hurt.

Jim Haseltine wrote: ↑

Mon Dec 14, 2020 7:35 pm

Wonder if the monitoring system is blocking my charger? Okay, later in the week I'll go ahead take the battery off, fully charge it then refit it with a changed number. Can't see that it'll hurt.

I assume that's exactly what happened with mine, I didn't fully charge mine but but it still seems to have fixed it simply by changing the serial number.

Jim Haseltine wrote: ↑

Mon Dec 14, 2020 7:35 pm

Wonder if the monitoring system is blocking my charger? Okay, later in the week I'll go ahead take the battery off, fully charge it then refit it with a changed number. Can't see that it'll hurt.

You're supposed to charge from the nodes in the engine bay, for that reason (the monitoring system). Think it's explained in the car manual.

Well, we'll see what happens. Having been more than slightly shocked by the price ECP list on their website for a 'named' battery I gave local factors a call to see what their price is - £158 and some odd pence for a Yuasa, which is pretty much what I remember paying a couple of years back.
I really need to find that receipt....

Jim Haseltine wrote: ↑

Mon Dec 14, 2020 9:38 pm

Well, we'll see what happens. Having been more than slightly shocked by the price ECP list on their website for a 'named' battery I gave local factors a call to see what their price is - £158 and some odd pence for a Yuasa, which is pretty much what I remember paying a couple of years back.
I really need to find that receipt....

I recently replaced mine. Try Tayna batteries.

I got a Varta OE spec and direct replacement for £109.5 + delivery. Came with 5 yr warranty. They do few other makes as well if that's your thing.

Well, it's on charge in my garage now. Checked out Tayna in case I can't find the receipt - their price for the same battery (Yuasa YBX5020) is £113.98 inc. delivery while my factors are as mentioned earlier £158.62 and I'd have to go to get the thing. The filtering on the Tayna website is a nightmare but I can't argue with their prices.

After 36 hours on charge in my garage the sight glass on the battery was back to showing green. After leaving it disconnected for a week it was still green and on reconnecting my charger it showed almost zero draw. It's back on the car and I've changed the serial number by one digit. Now I've the problem of clearing the oil and other rubbish that was dumped into the exhaust from the turbo leaks - a load drained out of the RH down pipe when I had the exhaust off and some seeped out when I had the tail section standing on end in my garage but judging from the way that the tail pipes are doing a fair impression of a destroyer laying a smoke screen in 'Sink the Bismark' there must be quite a bit still in there. It'd probably clear if I could take the car for a run but thanks to the too close for comfort presence of a traffic cop establishment I don't want to risk it.

When changing a battery you have to tell the system its a new battery (via VCDS), if its one it recognises (code number) all is well and good, if its one it doesn't recognise simply tell it the serial number has changed by one digit and it will accept it and move on. All should be good. I did this with a VARTA equivalent and all has been well over the last couple of years since it was changed.

Can anyone explain how to code new battery via VCDS? Thanks!

Kunkku wrote: ↑

Thu Dec 31, 2020 3:08 pm

Can anyone explain how to code new battery via VCDS? Thanks!

Use CAN gateway (19) and if not a recognised battery make, just change the serial number by at least 1 digit. YouTube link below

https://youtu.be/IJAScg6JrYI?t=181

That's if it's a CAN car. Earlier ones use 61 Battery (it's on the second page) then Coding. Same method though, change the serial number by one digit.

Jim Haseltine wrote: ↑

Thu Dec 31, 2020 6:10 pm

That's if it's a CAN car. Earlier ones use 61 Battery (it's on the second page) then Coding. Same method though, change the serial number by one digit.

Any idea when it changed, was it the face-lift, or mmi 3g? I know my 2010 plus was a CAN version