How do I use the mechanical key? // 12V battery was dead

[spence7788]

Given the hassle / inconvenience you’ll undoubtedly have in getting it replaced under warranty if at all I’d just replace it yourself & It’s done & not just an awful quality SAIC replacement that will most likely give you trouble next winter.

They really are awful quality after a bit of research I did a while back, I changed mine a couple of months back as preventative maintenance & it was nearly 2 years old & 90k miles, size 063 & there about the cheapest boggo battery you can buy, I got a Kumho for about £30! Would have put a Varta or Bosch but I’ll be getting rid in about 6 months, Voltages are much higher when left sitting I’ve noticed & I think mine was on its last legs even used daily before winter & would have given up soon.

Very easy quick job.

 

[tsedge]

Modern 12V batteries are often poor quality. Price wars in the early noughties killed off a lot of the better makers. You can still get decent leisure batteries (which have the right characteristics) but they cost a packet.

These days I'd suggest replacing the 12V battery every 2-3 years unless it is a premium make.

 

[kimptoc]

I took the car to the MG garage this week. They assessed that one of the terminals was loose and had tightened it; they suggested I charge it and try again. If there is no joy, then replace the battery.
They did not seem to know about any software updates.
I tried charging it, but there was no improvement (I even tried a trickle charger, but no joy), so I replaced it with the EA472 battery mentioned in this thread.
Seems ok so far (admittedly, only one day later).

 

[Jto]

I took the car to the MG garage this week. They assessed that one of the terminals was loose and had tightened it; they suggested I charge it and try again. If there is no joy, then replace the battery.
They did not seem to know about any software updates.
I tried charging it, but there was no improvement (I even tried a trickle charger, but no joy), so I replaced it with the EA472 battery mentioned in this thread.
Seems ok so far (admittedly, only one day later).

How are you getting on with the new battery has this sorted it out, as it’s been a few day just check the battery terminals 10mm spanner.

I just thought I'd update this thread... it's still happening; in fact, it's getting worse; every trip or so, it's having the issue. Although it seems to be changing slightly - the car unlocks, but the front beams flash, and it won't come on. So, I used the lithium charger, which gives it enough juice to start. I tried turning it off and leaving it, but when I returned an hour later, it still didn't start, so I had to jump it again. I must give it a drive like the 12V battery is having issues. Although it still shows as good once things are running again.
I have it booked into the garage in just over a month.

When you a lithium charger do you mean a jump pack?

 

[kimptoc]

How are you getting on with the new battery has this sorted it out, as it’s been a few day just check the battery terminals 10mm spanner.

Going great. Its like a new car. Thanks for the tip.

When you a lithium charger do you mean a jump pack?

I have this

 

[Ian Bittern]

Here is a quick update on this. It happened again yesterday. Definitely not cold related (~20c)
Used the battery charger I got after the first time this happened. Powered up straight away. Gave it 10 mins and it seemed fine to drive away, which I did. 30mins drive to work. Left it and worked fine coming home in the evening.
12v battery was showing 13.8V while driving.
A day later the car is off/just been fully charged. The app shows the 12V battery is at 12.9V.
Strange.

12.9 would be a very good normal voltage after charging has stopped , under 12.4 would start to be a concern