540C Battery issues

[gt3driver73]

My car is almost 3 years old and my battery is going down even when it's on trickle charge.

I used to have it on trickle charge if I didn't drive the car for say 4 days, but eventually when I was ready to sell I gave it to a dealer on sale or return. Despite asking him to make sure it was constantly charged I strongly suspect that they didn't bother at all to charge it. I eventually gave the car to a different dealer who has it now.

He told me that no matter how long it was on trickle charge, that it never really got above a few days on the display. McLaren assistance came out and ran the car and said that the car has to be run to properly charge the battery, say about 30mins each week. He therefore said my battery was fine.

I'm thinking though that the battery has actually been ruined as I'm sure this can't be right, surely the battery conditioner should be enough to charge the battery without running the car?

Any help or advise would be much appreciated!!

Thanks.

[The Surveyor]

The battery conditioner should keep the battery in tip-top condition, that's the point of a conditioner rather than a charger.

Have you any way of proving the first dealer let the battery run flat?

[MOD500]

I would drop car at McLaren dealer before 3 yrs warranty is up and let them carryout battery test (is set test procedure from Mc I think)? They will charge and check how quickly battery drains and confirm if faulty or not, and would be changed under warranty if found to be faulty? Hope you get sorted.

[duka]

battery won't be changed under warranty

[Targarama]

Sounds like it needs a good run? The 'days left' display may not be accurate if its been standing forever. Try using the car for a week or two, then put it back on SOR once the battery is happy? Better than £3k for a new battery.

[MOD500]

duka said:

battery won't be changed under warranty

My understanding is that battery covered under original 3 year warranty? (likely not covered under the extended warranty tho)

[PGNSagaris]

Targarama said:

Better than £3k for a new battery.

Sorry, excuse me ?!!??!! £3k. For a battery.

Madness

[anonymous-user]

They had a similar problem on a McLaren on that Yianni car show on Dave (yeah I know ....). Turned out to be a faulty charger.

[Targarama]

PGNSagaris said:

Targarama said:

Better than £3k for a new battery.

Sorry, excuse me ?!!??!! £3k. For a battery.

Madness

Lithium Ion lightweight affair, not your average lead-acid brick (I really enjoyed fitting the super-light battery in my TVRs). Plus Mctax. There may be alternatives for less but that would probably mean warranty not valid after fitting.

[anonymous-user]

Targarama said:

PGNSagaris said:

Targarama said:

Better than £3k for a new battery.

Sorry, excuse me ?!!??!! £3k. For a battery.

Madness

Lithium Ion lightweight affair, not your average lead-acid brick (I really enjoyed fitting the super-light battery in my TVRs). Plus Mctax. There may be alternatives for less but that would probably mean warranty not valid after fitting.

Still, 3 grand?! That's a lot of supercar tax.

I have one of these - less than grand with charger and the RESTART function is a great 'backstop'.

https://www.antigravitybatteries-uk.co.uk/automoti...

Edited by anonymous-user on Wednesday 13th February 11:01

[Thorney]

I'd ignore the battery condition report on the dash until after a drive, they are a bit vague.

We are looking at alternative battery suppliers at the moment, they are a lot of money from Mclaren.