Odd failure to start

[Bill]

My Mini (05 Cooper S FWIW) didn't start the other day. Absolutely nothing but flickering dash lights when I turned the key. It didn't turn over, no clicks, nothing. I made sure fans etc were turned off and tried again a few times with the same result. Wound the window down to push it and it was very sluggish.

Luckily I was parked near a hill so bump started it without issue and drove 3 miles home. Turned it off when I got home and restarted it immediately. And it worked fine later on despite not being charged up or run any distance. It's also started absolutely fine this morning.

There are no error codes I can see with a half decent code reader. And it had a decent run at the weekend.

Does this sound like a dying battery??

[Dynion Araf Uchaf]

yes

[Bill]

It's a bit odd isn't it?? It is really all or nothing and intermittent...

[Fastpedeller]

Once you had it bump started there was charge being supplied from the alternator to the battery. The fact the car was driven will mean the engine became warmer, so the oil became thinner - later in the day this would make it easier to start, along with the small charging that had taken place.
ETA - if it's on its original battery it's done well. I reckon 5-7 years max for a battery is par.

Edited by Fastpedeller on Tuesday 10th January 15:34

[Shedding]

I had the same symptoms on my 52 reg Mini. It would be fine for a week or two and then just fail to turn the engine over. A new battery solved it.

[cuprabob]

Probably the battery but could also be a dodgy connection.

[President Merkin]

Check your earth points, especially the big one on the left of the engine bolted to the engine mount. After that, get a multimeter on the battery. You want 12-12.5 v minimum with the car not running.

[E-bmw]

For the record if you have 12v it is about as flat as you can get & still have a slight chance of it starting.

Between 12.6 & 12.8 is a good battery fully charged.

Every 0.1 volt below 12.6 is a loss of around 20% charge.

[Bill]

Cheers all, I'll have a rummage...

[President Merkin]

Did you get to the bottom of this Bill?