Flat battery

Evening all

To wit, modern cars and batteries. Don't let 'em go flat. One of my childhood friends asked me to take a look at his dear departed Uncle's Ford Focus. Unloved, unused and unwashed since January. Poor thing!

I chucked a bucket of water over it, and got to work. No, the keyfob isn't knacked, the car has a bad case of ZERO volts. Opened the door with the key and we have the beginnings of that "old car" smell.

Pulled the Bosch battery, dated 0118, so not old. Plugged it into my Sealey 8A charger, and promptly blew the charger fuse.

It seems it was made of stronger stuff. I POKED IT with the soft cushions, namely a big brute of a Kamasa thing with wheels on it that I borrowed from a mate.

Anyway, I got the battery charged, placed it back into the car. Car went apeshit. BEEEP BEEEEEEEEEP! Needles alles uber der platz, random messages.

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Plugged in the netbook, I had a little schmoke

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Diagnostics crashed. The car thought that the traction control was knackered. (this happens)

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Reset the instrument cluster from the netbook.

All is serene

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What a well behaved Ford Focus you are!

All well and good, I have the kit and Fords are generally well behaved, but I heard just today of a Merc A Class that needed a new ECU due to a flat battery. Warranty job, and I'm calling bullshit on the dealer, but worth thinking about.
 
It's also worth knowing that in many modern cars, if the instrument panel is really goosed, the car won't run, and you're looking at £BIG.
 
Is the Focus diesel or petrol?

Some of them are silver calcium batteries and when they fail, they just fail. Can't bring them back to life.
My stepdaughters Focus just did the dry solder in the instrument panel thing, go over a speed bump and it shuts down the instrument cluster which immobilises that car

Not difficult or expensive to fix, if you know what the problem is.
 
Is the Focus diesel or petrol?

Some of them are silver calcium batteries and when they fail, they just fail. Can't bring them back to life.
My stepdaughters Focus just did the dry solder in the instrument panel thing, go over a speed bump and it shuts down the instrument cluster which immobilises that car

Not difficult or expensive to fix, if you know what the problem is.
Well said. The car I posted about is a Focus Zetec (I know that's a trim level now) with the 1.6 Sigma engine. I reflowed the solder joints on the IC of an Audi Titty for a mate: just a matter of touching the soldering iron on the joints and letting it melt and re-coagulate. He was very pleased, got me very very drunk while he and his wife bought me and my missus dinner: The Audi dealer was looking for, literally, thousands of pounds.
 
I have a solar panel in the back window of both cars, plugged into a 12v socket (yes, it is permanently live).

Sent from my neocore_E1R1 using Tapatalk
An excellent idea. A friend uses three on his A-M Vanquish. Those cars have SHIT electrics with constant current drains. While the car (infrequently used) always needs a jump pack to crank the V12, the solar panels keep the computers sane.
 
Once a lead acid battery has dropped to a couple of v its farked for good, it will take big amps from a charger but it won't hold it. They should never go below 50% charge.

I live off grid on solar .
 
It's also worth knowing that in many modern cars, if the instrument panel is really goosed, the car won't run, and you're looking at £BIG.
A mates merc was suffering the same, and he was worried that as the inspector would not be able to read the mileage that it would not be able to pass impending MOT.
I tried the old fashioned remedy of a good old smack with my hand and it miraculously sprang back to life.
 
A mates merc was suffering the same, and he was worried that as the inspector would not be able to read the mileage that it would not be able to pass impending MOT.
I tried the old fashioned remedy of a good old smack with my hand and it miraculously sprang back to life.

SEE? GERMANS. They need a good smack. It's the only language the bastards understand. Commander Colin Maud walt.
 
Battery died on the Mégane while in France in the summer, out in the sticks. I knew you can't bump start them, (steering lock is electronic ) but got a jump start, picked up a charger at the hypermarche and gave it a full charge. Next morning dead again. Check the earth. Suspect battery is screwed but it could be alternator so call the breakdown service. When the truck eventually reaches us, turns out I was right. New battery then. 150 effing Euros, for a bog standard battery I could have picked up for £50 in the UK. Cue Gallic shrug.
Postscript.
Hammering down a back road with Ms Civvy driving.
"What's speed limit here?"
"80k"
"I'm only doing 78"
"Yeah, but mph, the speedo has reset after the battery was changed!"
 
Once a lead acid battery has dropped to a couple of v its farked for good, it will take big amps from a charger but it won't hold it. They should never go below 50% charge.

I live off grid on solar .
We often used to run Wheelbarrow batteries well below 50% with no issue in use or recharging.
 
Battery died on the Mégane while in France in the summer, out in the sticks. I knew you can't bump start them, (steering lock is electronic ) but got a jump start, picked up a charger at the hypermarche and gave it a full charge. Next morning dead again. Check the earth. Suspect battery is screwed but it could be alternator so call the breakdown service. When the truck eventually reaches us, turns out I was right. New battery then. 150 effing Euros, for a bog standard battery I could have picked up for £50 in the UK. Cue Gallic shrug.
Postscript.
Hammering down a back road with Ms Civvy driving.
"What's speed limit here?"
"80k"
"I'm only doing 78"
"Yeah, but mph, the speedo has reset after the battery was changed!"
You bought a Renault. Rookie mistake. Slap yourself, Di Nozzo-style, and buy an proper car. Montego turbo diesel. That's a MAN's car, not some girly swot Renault.
 
We often used to run Wheelbarrow batteries well below 50% with no issue in use or recharging.
My old boss fancied himself as expert in electronics and had rewired a charger to produce a lot of amps.
He left it on full charge overnight on a huge cell, off of a Merc 500 sl.
When I entered the workshop the next morning I noticed a funny smell and saw that the battery had boiled away about half of its electrolyte.
I told him to put his fag out and go back to his office.
The battery was ruined and cost about two hundred quid to replace.
 
You bought a Renault. Rookie mistake. Slap yourself, Di Nozzo-style, and buy an proper car. Montego turbo diesel. That's a MAN's car, not some girly swot Renault.
There is a thing called a diode pack inside an alternator and it will drain the battery.
If it normally fails then the ignition light will stay on, even if you take the key out.
But not in all circumstances.
 

Truxx

LE
Once a lead acid battery has dropped to a couple of v its farked for good, it will take big amps from a charger but it won't hold it. They should never go below 50% charge.

I live off grid on solar .
Years ago ( when cars had carbs and points and stuff) a lead acid battery suffering as you describe would be revived by the process known as "sitting down". First a bulb was connected to the terminals and the whole thing left to discharge completely. Then it would be topped up with a drop of fresh acid before being banged on one of the old style chargers where you could select the amperage. Two hours at 8A followed by a good 24 hours at a couple of amps.
 

MrBane

LE
Moderator
Kit Reviewer
Reviews Editor
I also didn't realise that many modern cars don't allow for a jump start from another car in order to protect the system electronics. Took me a long while trying to charge a dead battery on a Hyundai i30 to figure that one out (Well I didn't, the local recovery mob told me when they tipped up.)
 
There is a thing called a diode pack inside an alternator and it will drain the battery.
If it normally fails then the ignition light will stay on, even if you take the key out.
But not in all circumstances.
Boom! This. A mate's W203 C220 CDi shat the bed, flattening the battery overnight every night. We traced it to a fault in the block heater, which wasn't switching off. Damn thing is unfused, and was pulling 27 amps. It's wired up along with the starter motor, and is above the starter, but under the inlet manifold. Horrible to get to. I modded the loom to bypass it. Job jobbed. Not. Battery flat again.

Pulled the alternator wiring, and the battery stayed charged. Good stuff, we need a new alternator. 400 notes for a new one! Got a diode pack free gratis from Auto Benz up near Aldergrove airport. "It's used, we haven't tested it. We don't normally do this, but if it works, drop us a line on Facebook. Good luck."

It worked. That W203 (it's a coupe) is a nice car but by gum, it's unreliable. It's an auto, and I had to tow it once. You have to go really slowly, and stop every few hundred yards so you don't wreck the 'box and diff. My pal who owns it phoned our local recovery guy who was unavailable, but gave advice:

"What are you towing it with?"
"Jaguar X Type"
"What model?"
"Err hang on. It's a petrol one, 2.5 V6 with all-wheel drive."
"Good. Tell the Jag driver to take it easy. Throw that Mercedes away and offer the Jaguar owner money for his car."

:p:D
 
I also didn't realise that many modern cars don't allow for a jump start from another car in order to protect the system electronics. Took me a long while trying to charge a dead battery on a Hyundai i30 to figure that one out (Well I didn't, the local recovery mob told me when they tipped up.)
My late girlfriend's sister phoned me when her Hyundai i10 suffered a no cold cranking amps situation. Her brother had had his trusty 1990 Rover 214 GSi* connected to it for ages, but no dice.

I disconnected the battery from the car and threw on the jump leads from the Focus. My revs dropped and recovered, and I left it running for a few minutes. All good, the Hyundai started when reconnected.

* that Rover is an amazing car. Closed-deck K Series engine, with the triangular air box. He still has it, there's something like 300K miles on it.
 

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