[Dorchester]

No power at all in the 25!
My wife was going to the market, opened the doors with the fob as usual and then since no power at all: nothing is lighted when you open the door, and even the fob is now unable to open or shut the doors.
Indeed I tested the battery: 12.2V.
But just in case I've put it in charge.
What's going on? Never ever had I such a problem with any of my cars.
It's like there's no battery.
The battery is a very good one, an AGM Banner (Austrian brand), not old (3 years), duly & regularly maintained with my Noco Genius charger.
I'm dejected...
The car was fine until yesterday evening: it worked without any problem until 9.30pm...
Thanks a lot for your kind help.

[RoverRevival]

Check all the earths

[RoverRevival]

Check all the earths.

Are you able to get a jump start?
Could be the cell in the battery has died.

[Dorchester]

Check all the earths.
Are you able to get a jump start?
Could be the cell in the battery has died.

Nothing looks wrong actually under the bonnet. The lead from the battery to the slam panel is rather short.
But after an hour charge I noticed that the power was back in the car.
Then I tested the fob and shut the doors. Then impossible to open it back again with the fob: no power again in the car!
But the charger being still on, the power came back again after a short while!
Hence I took an hair-dryer to dry battery connectors and the surroundings. Then I put a few drops of WD40 on the extremity of both leads (+ & -) including the extremity on the slam panel.
Now I'm waiting till the battery is in full charge (the progress is going nicely), then I'll try to start up the car.
But why is the power gone when I successfully used the fob to shut the car?

[itcaptainslow]

As said-I’d be checking all the earths firstly. Most common one to give trouble is the Earth from battery to body-it can fray, corrode and the connection to the body rusts.

[Johnny 216GSi]

But why is the power gone when I successfully used the fob to shut the car?

Older batteries give up at this time of year. It's the cold overnight temperatures. Could simply be a sign you need a new battery - it always has been when this has happened to me.

Shutting the doors with the fob causes several amps to be drawn from the battery momentarily. This discharges a battery which isn't holding much charge. Then nothing works again afterwards.

You might be better off just fitting a new battery rather than suffer a winter full of "will it / won't it" starting issues every morning.

[Dorchester]

Here are the last developments.
Nothing looks corroded or rotten, broken or knackered under the bonnet and no water ingress despite a miserable weather.
But the battery had a very weird 'behaviour' in the beginning of the afternoon.
After 3 or 4 hours charge, I tried starting the engine and there was a nasty flickering of the dash lamps & rather high pitched sounds. It looked like the amperage wasn't stable. When stopping lights on the dash were rather fading.
But I succeeded at the third attempt (mind that battery off, the ECU has forgot it was fuelled with ethanol) and at idling the revs were good.
I'd got 14.4V when running and 13.05V when off.
Hence my better half is gone shopping and I'm hearing now she's back.
Probably a warning from the battery before a likely death?
You may likely be right @Johnny 216GSi. Thank you.

[Paul_1978_yorks]

Sounds like a faulty battery. I highly recommend https://www.tayna.co.uk/ for a replacement

[Dorchester]

Sounds like a faulty battery. I highly recommend https://www.tayna.co.uk/ for a replacement

Thank you Paul for your interesting advice, but living on the continent any shipping from the mainland is heavily priced unfortunately.
Hence I've just ordered a good VARTA C6 Silver Dynamic 52Ah - 520A on amazon.fr at 65€ (£56).
Exactly the same costs 10€ more (£8.60) on ebay.fr or 20€ more (£17.20) at my local retailer!

[boxermanrt]

We had a similar problem with the wife's facelift 25 a couple of months ago and we traced it to a connection at the back of the engine bay between the water tank and the fuel filter unit. The connector looks like a white plastic inline fuse holder, but inside it is a male / female spade connector the cable going to this was corroded but would still conduct a low current, but would breakdown when a bigger current was called for.