Battery voltage low ?

If it has no (or a flat) battery, how do you open the window?

I'm assuming it has electric windows, of course.)

Chris

Connect the battery, wind down the window, disconnect, follow the 3 min rule, then reconnect.

Tim.

What a faff!

Chris

It depends on the state of charge and when you measure it. The ambient temperature make a difference too.

There is no need to worry about the off load voltage provided it starts ok.

There's no need to disconnect a battery when charging it with any sort of charger likely to be found at home.

In normal use, modern cars never need an external charge.

Generally sound advice. However we're seeing an increasing number of specifically MB and BMW's with the battery monitor unit in the neg lead or the efficient dynamics models getting their ECU's in a right muddle (some convieniance items not working) or even refusing to charge their battery at all either when suffering with a weak battery, or one that's been charged from an external source without being totally disconnected.

However, just had a E60 where the battery drop tested at 80% capacity and was starting the car just fine but throwing error codes for voltage deviation and the stop/start not working. A new monitor unit failed to fix it, but a new battery did ! :-S

Tim..

Battery is still going strong :) and I have no plans on touching it.

I took your advice and investigated what could be causing the iregular starting. I started with the plugs and leads and turns out I had a cracked spark plug! so I changed them all and put new genuine leads on aswell as I know the ford coil is fussy and I wouldn't want to upset it given what they cost to replace for a few extra quid on the genuine leads and plugs.

The irgular starting has not returned :)

Whatever happened to the old 'tin can' coils? In 45 years driving I never knew one of these to go faulty.

Or generate a spark strong enough for an engine with a decent amount of swirl. & Ive only had 1/2 your experience, so way less experience of can coils& I've seen a couple of faulty ones.

Eh? They went faulty quite often.

Yep, best one I ever found was on a mini, if you drove in a straight line it was perfect, but if you went round a roundabout it would cut out, hours of fault finding eventually found the answer: the coil had lost SOME' (not all) of its internal oil, when cornering the remainig oil was flung to one end and the coil shorted internally.

That's a head-scratcher. Heat failure was the most common, but sometimes even that would be intermittent. They were cheap enough to replace at high-ish mileages anyway, so a precautionary binning of the old one (or simply tucking it away on a shelf for the next old snotter to get booted out) was prudent.

The coil in question was only a few miles old !!!!

Heh. I've done that too - brand new in box was faulty. And the number of dud new Champion plugs... the DoA rate was likely

absolutely, we sold tens of thousands of NGK without problem. We were selling new Suzuki motorcycles, when they came in (new in the box from Japan) they might be fitted with NGK or ND, if they had ND we learnt to throw them away before even running them, if we left in ND we often had reports of poor running at the 500 service (yes, 500 miles for the first service) and had to replace them anyway.