R8 flat battery

Author
Discussion

hosedoctor

Original Poster:

664 posts

216 months

Sunday 19th February 2017
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Sorry if this been posted before guys,went to start the other halfs R8 today and the battery is dead! First question,is this a common thing after sitting for a while? And secondly what's the best battery charger/ maintanence? Thanks

Efbe

9,251 posts

165 months

Sunday 19th February 2017
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how long is a while?

hosedoctor

Original Poster:

664 posts

216 months

Sunday 19th February 2017
quotequote all
4-6 weeks? I had a maintenance charger plugged into the cigarette lighter but not sure what's happened?

cuprabob

14,419 posts

213 months

Sunday 19th February 2017
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hosedoctor said:
4-6 weeks? I had a maintenance charger plugged into the cigarette lighter but not sure what's happened?
Have you checked the Cigarette Lighter 12V is "live" all the time as most modern VAG cars it's only "live" with the ignition switched on. It has to be a constant 12V for the charger to be of any use through that route.

Optimate / Accumate / CTEK chargers are all very good and come with connectors and leads to connect directly to the battery.

If the car battery is over 5 years it will be by it's best and may struggle to hold charge especially at lower ambient temps.

Edited by cuprabob on Sunday 19th February 21:50

hosedoctor

Original Poster:

664 posts

216 months

Sunday 19th February 2017
quotequote all
Ahh that would make sense,the car is a 2015. Thanks for the help.

cuprabob

14,419 posts

213 months

Sunday 19th February 2017
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Battery should be fine then. It will just have discharged over the period. The alarm draws current albeit a low amount.

Efbe

9,251 posts

165 months

Sunday 19th February 2017
quotequote all
4-6 weeks should be fine though. 4 months and I would expect issues, not weeks.


PositronicRay

26,957 posts

182 months

Monday 20th February 2017
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Efbe said:
4-6 weeks should be fine though. 4 months and I would expect issues, not weeks.
Depends on the use prior to being parked up.

Trev450

6,314 posts

171 months

Monday 20th February 2017
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If the OP has a tracker fitted they draw additional current too. As already mentioned, CTEK battery conditioners are hard to beat.

cuprabob

14,419 posts

213 months

Monday 20th February 2017
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Also with an R8, I would guess they would fit the minimum capacity battery they could get away with in order to keep weight down.

Trev450

6,314 posts

171 months

Monday 20th February 2017
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cuprabob said:
Also with an R8, I would guess they would fit the minimum capacity battery they could get away with in order to keep weight down.
I wish. Its a whopping great 110 A/H and a right pita to change.

cuprabob

14,419 posts

213 months

Monday 20th February 2017
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Trev450 said:
I wish. Its a whopping great 110 A/H and a right pita to change.
I take that back then...

Adrian E

3,248 posts

175 months

Monday 20th February 2017
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Sounds like it might be the same truck battery fitted to my S8 and s5 in that case! Huge great lump of a thing

If it's still under warranty get the battery swapped if they'll entertain it. A deep discharge doesn't do non-AGM batteries any good. Worth charging too before or after fitting as batteries can be only half charged when supplied. Last OEM battery I bought needed a 20 hr charge!

Emonda03

740 posts

199 months

Tuesday 21st February 2017
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I had the same issue, a new V10 plus, parked up in my garage, battery full, new car only done 1,700 miles..went away at xmas etc, come back after 6 weeks flat. Got a Ctek charger and attached it , kept throwing up an error message. Called out audi assist,he told me that if the battery is really flat, the ctek cannot see it, doesn't know its attached to a battery , it relies on a small current passing back to the charger to show it it is connected to a battery , so hence why it wouldn't work. Anyway AA man put his booster pack on it, and 15 mins later back to a 40% charge etc, and all good...must admit the Audi assist man was great.
At this point I found it ridiculous that audi do not acknowledge battery conditioning in the car's manual, or indeed put a port or easy access to the battery, bearing in mind many of these cars are not used daily. In fact in the manual it makes a point of saying the car is clever and shuts down systems when not in use to prolong life etc...er no audi clearly not
I have had porsches/Ferrari's etc and they all say to plug in a conditioner if not used etc, Ferrari make it easy by actually putting a handy port in a good place & providing a conditioner, Porsche's I have charged through the cig lighter access ( by the way don't think you can do that in a audi, as someone said don't think its live to charge )meanwhile audi make it very hard to get connection to the battery. Anyway I ended up getting a fly lead permanently fitted on the battery & just plug it in to the tender now when not in use.
Ironically as the car was kept in my garage, I leave it unlocked, I thought this the best way to prolong life as the alarm is not armed, this I have been told is the wrong thing to do. Apparantly by leaving the car unlocked the systems stay live, waiting to go, and use power being in a ready state, if you lock it then it knows its not being used and it shuts systems down, so a locked R8 uses a lot less battery than an unlocked one if you are storing it...so that would make sense as to why it drained so quickly......
hope this info is of use to you....cheers