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Just how dead is a really flat battery?


Stilllearning

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Thursday, I went to the car to discover that some idiot had left an electrical system on for over 24 hours, thus completely flattening the battery. So flat that same idiot had to use the manual system to open the driver’s door, and not a glimmer of life anywhere on the dash.

A temporary battery has been put under the bonnet, and the dead one, only just 2 years and a week old ( naturally) put on charge. It’s showing a charge rate of just under 3 amps immediately. So how dead is it likely to be?

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We got back to find C's car had a flat battery, needed to manually open the door etc. We just put a small (6amp) charger on it for 24hours and all was fine. Second time after a month of sitting there wasn't as bad just jump started it and its been fine since.

 

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I would have put the battery on charge if 

1/ I hadn’t parked the car across the square, and

2/ the bl***y negative terminal 10mm nut can only be accessed with a very slimline long socket.

Last time i needed one I went to our local Renault dealer and borrowed his, but this happened at 6 pm , of course.

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2 minutes ago, Stilllearning said:

I would have put the battery on charge if 

1/ I hadn’t parked the car across the square, and

2/ the bl***y negative terminal 10mm nut can only be accessed with a very slimline long socket.

Last time i needed one I went to our local Renault dealer and borrowed his, but this happened at 6 pm , of course.

A well designed French car ???

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Just now, Loddon said:

A well designed French car ???

Just a typical modern car, designed to make work for the dealerships.

The local tyre repair man I called out, who does a basic breakdown service, agreed with me about modern bl***y cars, whilst reminding me how hassle free his lovely old Citroen Acadiane is. And no he still won’t sell it to me.

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1 hour ago, nicknorman said:

A lot of modern cars with start-stop systems have AGM or other relatively hi-tec batteries, and these seem less prone to major damage from being run totally flat than a conventional flooded lead acid.

Hmm

i got back to uk after 7 months away. Car started fine. Drove it to Holland fine.700kms.

3 days later tried to start it , it wasnt happy.

Drove to Roubaix. Parked at hotel, wouldnt start again after unloading.

Had to buy a new battery in Roubaix with flu. Fun experience.

Its an agm as car has crappy stop start system.

They die very suddenly.

 

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47 minutes ago, Alan de Enfield said:

Oxymoron

Never yet been achieved - and we were suppliers to PSA !

I had a new Citroen BX.  when it went back for its 500 mile check I told the Citroen dealer it made a hissing sound.

 

he diagnosed a missing nut on one of the manifold/block studs.   he had to order a specially shaped spanner from Citroen to access it properly.

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58 minutes ago, Stilllearning said:

I would have put the battery on charge if 

1/ I hadn’t parked the car across the square, and

2/ the bl***y negative terminal 10mm nut can only be accessed with a very slimline long socket.

Last time i needed one I went to our local Renault dealer and borrowed his, but this happened at 6 pm , of course.

Italian cars too. I was going to change the feeble battery on a girlfriend's Fiat, but gave up when it became apparent that the brake master cylinder would have to come off first.

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3 hours ago, Tony Brooks said:

I suspect not very once you have recharged it. Most car batteries spend their time fairly well charged so it was only discharged for a few hours. It will have sulphated but I think most will reconvert given time.

Yes, probably ok. The girl child left her car on our driveway for a month with one of those gps black boxes fitted for her insurance. It was flat as Miss Norfolk when it came to start it. At that point we discovered that some scumbag had tried to screwdriver both locks so we couldn't get in. I now know how to break in to a Peugeot 107 with no signs of damage. The battery was fine after a charge.

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I once hunted for the battery on a Ferrari Dino. Found it in recess behind a rough flimsy grp panel held on with self tapping screws in front of the o/s/f wheel. Had to remove the wheel to deal with it.

1 hour ago, Stilllearning said:

I would have put the battery on charge if 

1/ I hadn’t parked the car across the square, and

2/ the bl***y negative terminal 10mm nut can only be accessed with a very slimline long socket.

Last time i needed one I went to our local Renault dealer and borrowed his, but this happened at 6 pm , of course.

Renault Scenic ???

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My car sat unused for about 4 months this year, started quickly when first used, but would not start after about a week, re-charged it but no good, had to get a new battery from Halfords (no choice really as limited mobility).

Same with the boat, initially cabin batteries OK, but they soon gave up...they were 7 years old though, car battery about 3 years old. I ran a Honda CRV, and never changed a battery in 11 years.

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Daughter in Laws Renault was struggling to start so I said it needed a new battery, had a 'look' at the battery and thought this looks complicated so decide to read the manual.

 

"DO NOT CHANGE THE BATTERY" (this is a dealer fitted part only)

 

Apparently if the vehicle is left without power for 'seconds' it wipes the memory of all the electronics, engine management system etc.

Spoke to my local garage (he does all our MOTs etc) and he concurred but said he had the equipment to do it.

 

It needs one of the 'plug in fault testing' testers plugging in and it will power up the electronics whilst the battery is changed.

 

Not all technology is 'good'.

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47 minutes ago, Alan de Enfield said:

Daughter in Laws Renault was struggling to start so I said it needed a new battery, had a 'look' at the battery and thought this looks complicated so decide to read the manual.

 

"DO NOT CHANGE THE BATTERY" (this is a dealer fitted part only)

 

Apparently if the vehicle is left without power for 'seconds' it wipes the memory of all the electronics, engine management system etc.

Spoke to my local garage (he does all our MOTs etc) and he concurred but said he had the equipment to do it.

 

It needs one of the 'plug in fault testing' testers plugging in and it will power up the electronics whilst the battery is changed.

 

Not all technology is 'good'.

Anyone who designed a car like that should be sacked. It's nothing to do with technology, just plain incompetence...

 

Also I smell some bullsh*t here, all the crucial data like engine management settings is normally stored in non-volatile memory precisely so it doesn't get forgotten if power is removed. I wonder what particular bit of the car electrical system broke this "golden rule"? Just forgetting radio settings or similar wouldn't justify a warning in capitals...

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1 hour ago, bizzard said:

The French always have to make simple devices complicated on cars.  Awful to work on generally. The Citroen Saxo was the only sensible simple car in my opinion. 2CV's arn't that simple, simply quirky. 

I beg to differ: 2cvs and Dyanes etc are very simple, just not like any old British cars. For example all you need to adjust the ride height of a 2cv etc is an 8mm spanner and a ruler :)

 

  • Greenie 1
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1 hour ago, Alan de Enfield said:

Daughter in Laws Renault was struggling to start so I said it needed a new battery, had a 'look' at the battery and thought this looks complicated so decide to read the manual.

 

"DO NOT CHANGE THE BATTERY" (this is a dealer fitted part only)

 

Apparently if the vehicle is left without power for 'seconds' it wipes the memory of all the electronics, engine management system etc.

Spoke to my local garage (he does all our MOTs etc) and he concurred but said he had the equipment to do it.

 

It needs one of the 'plug in fault testing' testers plugging in and it will power up the electronics whilst the battery is changed.

 

Not all technology is 'good'.

My Golf has a gentler warning - something along the lines that if the battery is disconnected the engine may run less smoothly for a short while until some systems have recalibrated themselves.

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1 minute ago, alias said:

My Golf has a gentler warning - something along the lines that if the battery is disconnected the engine may run less smoothly for a short while until some systems have recalibrated themselves.

Looking on a Renault forum, one of the problems is that the electric windows will not work unless they are re-programmed by doinf something with the button on the clock, and then 'jiggling' each window button up and down a few times.

 

Seems absolute nonsense and appalling design.

Mind you, I was reading that the French railway design engineers have produced new trains that will not fit into several stations.

 

The French train operator SNCF has discovered that 2,000 new trains it ordered at a cost of 15bn euros ($20.5bn; £12.1bn) are too wide for many regional platforms.

The BBC's Christian Fraser in Paris says that it is an embarrassing blunder that has so far cost the rail operator over 50m euros ($68.4m; £40.6m).

Our correspondent says that the cost is likely to rise even further.

Construction work has already started to reconfigure station platforms.

The work will allow new trains room to pass through. But officials say that there are still 1,000 platforms to be adjusted.

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2 hours ago, Onewheeler said:

Italian cars too. I was going to change the feeble battery on a girlfriend's Fiat, but gave up when it became apparent that the brake master cylinder would have to come off first.

Skoda fabia vrs. To change headlight bulb remove front bumper. Which contains spotlights that have no remote connectors.

Specialist did it for me by removing ‘bits’ under bonnet. 45 mins labour.

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1 hour ago, Alan de Enfield said:

Looking on a Renault forum, one of the problems is that the electric windows will not work unless they are re-programmed by doinf something with the button on the clock, and then 'jiggling' each window button up and down a few times.

 

Seems absolute nonsense and appalling design.

Mind you, I was reading that the French railway design engineers have produced new trains that will not fit into several stations.

 

The French train operator SNCF has discovered that 2,000 new trains it ordered at a cost of 15bn euros ($20.5bn; £12.1bn) are too wide for many regional platforms.

The BBC's Christian Fraser in Paris says that it is an embarrassing blunder that has so far cost the rail operator over 50m euros ($68.4m; £40.6m).

Our correspondent says that the cost is likely to rise even further.

Construction work has already started to reconfigure station platforms.

The work will allow new trains room to pass through. But officials say that there are still 1,000 platforms to be adjusted.

Were the old 'King' locos a bit on the wide side too/Somebody will know. Mind you Brunel could make the odd blunder, he put the rails a couple of feet too far apart.

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3 hours ago, Mike Griffin said:

My car sat unused for about 4 months this year, started quickly when first used, but would not start after about a week, re-charged it but no good, had to get a new battery from Halfords (no choice really as limited mobility).

Same with the boat, initially cabin batteries OK, but they soon gave up...they were 7 years old though, car battery about 3 years old. I ran a Honda CRV, and never changed a battery in 11 years.

 

My car was also unused for several weeks over lockdown, and was a bit reluctant to start (original 8-y-o battery). Charged it up overnight and it has been fine since. Likewise, the cranking battery on the boat was pancake flat when I eventually got to it. I brought it home to recharge it, and once the "clever" charger had decided it was going to apply a voltage after all, the battery was reinstalled but a bit tired. I'll probably need a new one next year but I can't see the point in having a brand new battery discharge during the winter if (big 'if') I don't get to go boating.

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