Need a new battery

So how do these cars cope with any situation where the power needs to be disconnected for safety reasons? (i.e. anything which disturbs airbags)

They don't. Then it's a PITA. Particularly if, as is fairly common, you don't know the radio code.

As I said, what is the point in giving yourself any unnecessary problems when for a mere 2 pounds upwards you can get your battery properly fitted ?

I have a proper plug in thing to keep the power up if a battery has to come off, it saves me grief.

Why do you want to live in the past, next you will be scraping your big end shells, things move on and you need to keep up with the latest developments, which includes electronic stuff with memories !!!

Mrcheerful

I'm not sure why you replied to me Mrcheerful; I was merely pointing out that my Focus is untroubled by a battery swap whereas Steve Robinson has difficulties after doing his. (Although I'm not sure that I would find driving for eight miles too much of a chore.)

I also have a mains-powered battery saver, but TBH it's such a non-issue with my car that I don't use it. I have used it when working on other peoples cars however.

If I worked in the trade as you do, I would always use a memory saver if only to prevent grief from the numpties that forget their radio codes!

Chris

Surely coded radios have been around for long enough for people to make sure they have that code when buying a used car?

about 1 in 10 get the code with a second hand car. As far as I know all the mileage recorders are in (non volatile ?) memory and are never lost without battery power. If the battery goes flat while you are on holiday then something must be wrong before you leave, I find that a decent battery in a properly working (alternator ok) vehicle will last at least three months even with the alarm left armed, so a fortnights holiday should never be a problem.

Vauxhalls for instance lose their electric window settings, most Toyota and Lexus lose loads of settings, some of which need dealer reprogramming. The Toyota gearbox ecu relearns ok, just it changes at times you are not used to till it has re-established how you drive, I expect they lose all the mirror, seat and steering column info too.

XR2i was how I learnt the hard way, a battery change took a good half hour of driving until it would tick over again, it was the first time I came across the problem. A clutch change on a polo brought up the first 'I don't know the radio code' problem.

Mrcheerful

Your post was just the last I read, nothing personal intended.

My post was aimed at the Luddites -:)

Mrcheerful

The radio behaviours totally deliberate.

Doesn't need to be - OEM fit radios should be hard-coded to the car, IMHO.

no offence taken :)

I agree, it's just not worth the grief of what *might* happen if it completely loses all power (even if it's only the radio needing a code), when you can maintain an adequate voltage with a widget consisting of a PP3 battery, a clip for the battery, a diode (1N4148 say), a couple of croc clips, a metre of wire and the whole thing soldered together.

What purpose does the diode serve? Presumably it's soldered in series with one of the battery terminals.

Yep, stops you spraying the contents of the pp3 all over the interior when you reconnect the battery.

Here is the commercial one, by Draper. £12 + £5 delivery:

That's the one I have. 11.75UKP from here:

Three months? Not the case with many modern cars. Try nearer three weeks.

SteveH ( snipped-for-privacy@italiancar.co.uk) gurgled happily, sounding much like they were saying :

Ridiculous.

Makes it impossible to replace a dead unit with a known-good used one out of a scrapped car or one which has had a stereo upgrade. All it means is that shitloads of perfectly functional used OEM stereos get binned.

Doesn't just apply to stereos, either, with umpty-seven ECUs fitted to cars.

An example :- My local Cit Specialist has a Y-reg C5 HDi in at the mo with a snapped cambelt. It's going to be broken. I dunno if the ECUs in it are hard-coded to the car, but if they are, then they're all going to have to be binned, rather than used to replace ones that have gone dead in other cars - which will then be more likely to be scrapped, as nobody's going to pay the huge dealer price for replacements.

I see where you're coming from - but hard-coding would cut theft of OEM head units overnight, 'cos they're useless in any other car.

Swapping a VAG head unit appears to be a dealer only job these days - something to do with having to have a secure connection to the server in Germany in order to get the 'pass code' to re-code the stereo to the car.

SteveH ( snipped-for-privacy@italiancar.co.uk) gurgled happily, sounding much like they were saying :

How many OEM head units get stolen these days, anyway?

Very, very, very few, I'd suggest.