XC90 battery issue

[CocoPops]

Battery is completely flat, it was left unlocked for 4 days and I think it killed the battery.
So we got in via the key blade but even with a jump pack on the terminals in bonneted there is no life 👎
Called Volvo Assist, the sent a contractor who tried same 🤦*♂️
So now awaiting a Volvo master tech tomorrow morning.
500miles on the clock and it cannot start or open any doors other than passenger door.

[Murph7355]

Contractor that was sent to look at our door lock issue had a couple of spare, what looked like new, batteries in his van. Surprised yours couldn't get your car working.

I'd have a word with Volvo about that as that seems poor to me.

[Quacker]

Mine had a dodgy battery from new. Since it was replaced nearly three years ago, its been no trouble whatsoever.
I used to retail large diesel engined vehicles and there were a surprisingly high number of brand new vehicles that had very poor batteries that went dead flat within weeks of being factory built. These were changed for genuine brand batteries out of the stores, which were actually made by a different battery company to the ones fitted at the factory but had the same branding, and they never gave any bother. I know that some of the ones out of the parts department lasted ten years or so, yet the factory fitted ones seldom lasted three years.

Obviously that is a different case and is just an illustration of one scenario.

Should also mention that once a battery goes absolutely dead flat, it is scrap. The only solution is a new one. If it shows signs of life, it can be charged successfully. If the battery is faulty, as my original Volvo one was, it will probably self discharge again quite quickly, and certainly after a few days with the car standing.

[Fursty Ferret]

Just to add to what Quacker said, if you get the car started you'll need several hours of driving at motorway speeds to recharge the battery, and two or three times that to refill it to the extent that start-stop works reliably again.

I've accidentally discharged a battery to the point where it wouldn't turn the engine (left a door ajar for a week) but it went with a jump start and is still going strong.

AGM batteries are actually pretty tolerant to deep discharge. I now keep a lithium ion battery pack in the car which has enough juice for one good start attempt.

[gaby]

Originally Posted by CocoPops

Battery is completely flat, it was left unlocked for 4 days and I think it killed the battery.

I always leave the car unlocked, sometimes for more than 2 weeks. No problems.

[CocoPops]

Can’t be fixed at home, had master tech out.
Now to be recovered to dealer

[CocoPops]

So it’s now sat at dealer, thrifty have provided a 19 plate t5 XC90 as part of Volvo Assist.

Interesting how age and spec makes it feel a different car.

Also, makes me VERY glad I went for sunroof! It’s a very dark cabin without the sunroof.

[CocoPops]

Waiting for the list of obd codes, but essentially they carried out a battery reset?
It’s been test driven and will be checked again tomorrow.

Weird.... it was so very very dead, yet a “simple” battery reset has cured it.

Anyway, waiting for more information.

[Murph7355]

Originally Posted by CocoPops

Waiting for the list of obd codes, but essentially they carried out a battery reset?
It’s been test driven and will be checked again tomorrow.

Weird.... it was so very very dead, yet a “simple” battery reset has cured it.

Anyway, waiting for more information.

Even more surprised the guy called out didn't try this...

[CocoPops]

Originally Posted by Murph7355

Even more surprised the guy called out didn't try this...

Me too, how even is the “battery reset” carried out?