Car dead

[television]

My car today, all dead, well the key let me into the boot and the battery is down to 4volts after a charge, I find the drain is 1.25 amps.

Have to find someone to fix it :confused::eek::confused:

[Gollom]

:( :( :( :(

Sorry to hear that Malcolm - hope you get it sorted soon

P.S. - Your PM box is full

[gbjeppm]

Sorry to hear that Malcolm, with all of the advice you have dished out to the rest of us, I am sure you can dish some out to yourself.:)

My money is on a seat controller. But I specialise in misdiagnosis:D

[Matt45]

Malcolm, is it just the rear battery or is the front dead also, ie no engine start? Could you have left something on, as it doesn't sound like you to have electrical problems.

[television]

Malcolm, is it just the rear battery or is the front dead also, ie no engine start? Could you have left something on, as it doesn't sound like you to have electrical problems.No the starter one is fine, its the AGLM rear battery thats flat.

I cant leave anything on, the only difference is that I have left the car locked for this last few days as the current consumption is less when locked.

I will have a play later

[Matt45]

Glad it'll run if you need it to. Good luck and hope you get it sorted sooner than later - seems unfair after all the help you've given out.

[television]

Glad it'll run if you need it to. Good luck and hope you get it sorted sooner than later - seems unfair after all the help you've given out.

I put it down to a learning curve :):)

[Matt45]

True, but they tend to be very steep curves with SLs.

[robert.saunders]

Hope it gets sorted soon Malcolm

[grober]

Bad Alternator Regulator? It might feel warm to the touch with the engine cold? The "warmth test" can sometimes help locate a problem component which is causing the current drain-especially in this weather when the rest of the car will be cold.

[mr. shr]

My car today, all dead, well the key let me into the boot and the battery is down to 4volts after a charge, I find the drain is 1.25 amps.



Can't help you myself buy i know a bloke who can. Go to MBClub Forums and look up a bloke called Television. He knows loads about Mercs and he'll be able to get you going..............

................oh!!


Seriously mate, that's bad news. Hope you get it going again soon.

[esox]

My car today, all dead, well the key let me into the boot and the battery is down to 4volts after a charge, I find the drain is 1.25 amps.

Have to find someone to fix it :confused::eek::confused:

Same with me last week.
Went out New Years Eve and it was fine - no indications of any trouble looming.
Coupla` days later,put key in and absolutely dead - no battery juice whatsoever.
Charged battery,initially pulled 10A from the charger,after all day on charge only went down to 4A,thought battery had internal short.
Expecting new battery ££££.
Multimeter showed a drain of .7A with ig.off.
Assumed dash clock.
Another check showed 1.2A??
A-ha - door was open(interior light)

Hold on,i remember switching the light to manual,was it still on?
Yep:o

The 100% reliability of the 123 was restored - this one down to `operator error`
:rock:

[MBManInKen]

Ooops! :eek:

Sorry to hear that, Malcolm, but look at the bright side: at least it happened to someone who'll be able to fix it!! ;)

Hope it gets sorted soon - let us know the diagnosis!

[television]

Well I am on a learning curve here as the current cannot be checked when the battery voltage is under 12volt, and I should know that,as nothing can re set. Its now at 12.2 volt and pulling 51ma but the path of the leak has been broken and lost, also not checked with the car locked.

I will make up a test rig out of the car and lock it all up.

[television]

Well all sorted, I should have remembered that never do a current check unless the battery is fully charged.

On a fully charged battery the current is 40ma now. I changed it over for another with only 10 volts in it. Once again the draw was 1.25 amps.

This all shows that on cars the have the wake up and get ready circuits these are all trying to reset and warn of the low battery, and it is these circuits causing the large drain.

So the standing current is 40ma up to the point where the voltage starts to fall rapidly as the in current increases to the point where the battery will go dead flat

so a draw of 40ma equals out to 23 amps over 14 day, and that fits as the car has hardly been driven since before Christmas

[mr. shr]

Glad you got to the bottom of it.
Well done.

[grober]

Result Malcolm. :bannana: What are the ratings in amp hours on the 2 standard batteries anyway just out of curiosity? Sounds as if the SL was a prime candidate for a 24Volt System at the design stage.:(

[stevesey]

On a fully charged battery the current is 40ma now. I changed it over for another with only 10 volts in it. Once again the draw was 1.25 amps.

This all shows that on cars the have the wake up and get ready circuits these are all trying to reset and warn of the low battery, and it is these circuits causing the large drain.
Interesting design that - wonder it's deliberate i.e try to warn of a low battery (even if you do flatten it further) or an unintentional feature.

[television]

Result Malcolm. :bannana: What are the ratings in amp hours on the 2 standard batteries anyway just out of curiosity? Sounds as if the SL was a prime candidate for a 24Volt System at the design stage.:(

The starter one is about 40 ampere, but that is all it does the starter motor.

The AGLM is 70 ampere, and 12 months old, they are strange things, it took 3 hours to get it up to 12 volts and 6 hours later its up to 12.7 v , so it will need a few more hours yet, my max charge rate is 4 amps at this voltage.

I know that on the last few drives I started off with consumers off. As the car is not used much in the winter a good monthly charge is on the cards.

Thank you.

[television]

Interesting design that - wonder it's deliberate i.e try to warn of a low battery (even if you do flatten it further) or an unintentional feature.


The circuit that tries is to warn that you have no SBC brakes and the dash glows red, this cam on as soon as I was able to get in the cab and the battery was on the way up

[BTB 500]

I keep my R129 hooked up to an AccuMate maintenance charger now:

http://www.accumate.co.uk/AccuMate.htm

Gives great peace of mind.

[television]

I keep my R129 hooked up to an AccuMate maintenance charger now:

http://www.accumate.co.uk/AccuMate.htm

Gives great peace of mind.


I am such a tight old bu-----, yes I must buy one, in fact I will in the morning

[television]

I am such a tight old bu-----, yes I must buy one, in fact I will in the morning

Yes the Pro version is good for AGM batteries and at £48+ thats a super price

thank you

[Ian B Walker]

Well all sorted, I should have remembered that never do a current check unless the battery is fully charged.

On a fully charged battery the current is 40ma now. I changed it over for another with only 10 volts in it. Once again the draw was 1.25 amps.

This all shows that on cars the have the wake up and get ready circuits these are all trying to reset and warn of the low battery, and it is these circuits causing the large drain.

So the standing current is 40ma up to the point where the voltage starts to fall rapidly as the in current increases to the point where the battery will go dead flat

so a draw of 40ma equals out to 23 amps over 14 day, and that fits as the car has hardly been driven since before ChristmasGood result Malcolm. Great respect to you for posting the problem. Just goes to show that we can all learn something new each day.

[BTB 500]

I've got my standard AccuMate mounted on the garage wall using the optional wall bracket (£5 plus VAT) ... very handy.