Can car fail an MOT if the battery does not have enough power?

Flyboy152 wrote: »

But then a previous car of ours was ten year sold and still had the original battery.

But then my Scooby demolished a battery inside four years. The alarm seemed particularly draining. You wouldn't want to leave it more than a week even on a new battery in cold weather because it would flatten.

Not all cars/batteries are the same is the real lesson I think.

5t.

Deneb wrote: »

It didn't fail. It was a reason for refusal to complete the test.

if you read all that the OP wrote you will see that the test was abandoned through the test and not before logging on
this would be classed as a fail and show on the vosa website as having been failed

sinar wrote: »

i've just phoned up the garage, and mentioned my concerns to them, and they have said

"The battery is condition is not part of the MOT, but, it is a condition of the MOT that the battery is able to power all electrical items at once"

It does seem contradictory to me.

Ask for a demonstration of the problem... my car can run all of it's electrical systems while not having enough power to start the engine - I think you'd notice!

steveo3002 wrote: »

try it your self ...start the car and put on the headlights and hazzards , if the engine stays on and the lights all work then theres no problem

That doesn't really test anything - with the engine on all the power is coming from the alt, not the battery.

A "better" test would be to turn headlights / radio / heated rear window ec on, and THEN try to start the car.

interstellaflyer wrote: »

I've never seen an MOT tester switch all electrical items on at once so does seem strange, I can see their point if the battery was in such poor state that it would barely turn the engine over as that could be a potential hazzard

Why would a non-starting engine be a hazard?

The batteries electrical condition is not part of the MOT - although if it's insecure or leaking acid it could cause a fail, and if the battery won't start the car then they cannot complete the test.

sinar wrote: »

He replied by saying they were wrong to say that the car would fail the MOT because of that, however, the car could not be tested with the current battery, so could not pass the MOT.

They still have not explained why the current battery would not let the car pass.

sinar wrote: »

He said when they were testing the electrical systems the car cut out, they checked the battery and it was low (10.8 when it should have been 14, I think, not sure what that means, but he showed me a print out from a computer that he used to check it)

10.8v would indicate a dead (and I mean *DEAD* battery). But you say the car worked fine before... it's unusual for a battery to go so dead all of a sudden with no warning.

It's even wierder they tested it with a multi-meter if they haven't said they had any problems - a dead battery can show 12.xv so will *look* fine but not start the car. I'd wonder why they were testing it in the first place...

And why on earth would they be using a computer to test the voltage?!

sinar wrote: »

He said as the car cut out he could not continue to test it properly, so the only way to continue with the MOT was to have a new battery.

A flat battery won't cause a car to cut out - once its started most of the power of the power will come from the alt. You could drive with a dead/flat battery with no problems.





I can't help but think your battery was fine, and that they had a bunch of batteries spare....


In my "less knowledgeable" days I took my car for tracking. I mentioned it'd needed jump starting twice over the last few days so may well need it again... When I came back I had a bill for £120, as they'd replaced the battery without asking me. I asked for the old battery to go in (as I thought the price was a little steep, plus they'd charged me loads for labour & parts...) and they said they'd already disposed of it. I needed the car to get to Uni (that day to give coursework in annoyingly) so had to begrudgingly pay.