My Mercedes C Class runs battery down while parked

[tamoshanter]

There is a way to bring the battery back from way down zero, if you need to.

Boydy

how aprt from charging it :ninja:

 

[militar veteran]

Leaky diode in the alternator can cause this,try replacing it and check the belt tension to ensure proper charging.

 

[gnuuser]

how aprt from charging it :ninja:

first you need to test the electrolyte in the battery if it has the proper specific gravity and density then a low current (2 amp) charge over a period of a week should restore it.
your mechanic can do this for you
I always have a spare battery on hand in my garage

 

[guest119]

Charge in series with a load.
Something like a headlamp capsule ( phew, nearly said bulb!).
Same was as repairing power tools batteries, except L-ion.

Boydy

 

[solarsavings]

I made the mistake of buying c class cdi some years back and got rid of it as soon as the warranty ran out. While we had it would suddenly accelerate of its own accord, needed naff sensors. Expensive to have serviced and not great to drive.

About six months after we part exchanged it the new owner rang to ask if there had been any electrical faults as it kept draining the battery and had £3500 in warranty work done and it still wasn't fixed.

The only thing we had noticed just prior to selling a ticking from the speakers while the radio was off. We also realised that merc main dealers only employ part changers so my advice is don't take it to one of them.

 

[guest119]

I bought a 220cdi estate in 2007, a 52 plate, 140k, nearly 7 grand.
18 months later 169k, rotten round the rear arches, rear hatch, around the screen etc.
Multiple injector faults (£lenty).
Went out one morning and it wouldnt change up past 2nd. Merc said bring it in, pay for plug in and we will tell you what MIGHT be wrong with it. £control module this £control module that??????
So, onto e -blag ............£1500.
Won by a couple of Turkish lads in London who drove up for it and took it round the corner, phoned the AA (relay) and got it home.
I suspect they were breakers.
Pile of ----, never again.
Boydy

 

[tamoshanter]

Is this gadget any good for a battery draw test?

AUTOMOTIVE CURRENT TESTER - CF-02S

 

[gnuuser]

Is this gadget any good for a battery draw test?

AUTOMOTIVE CURRENT TESTER - CF-02S

it may test and read the current but i dont know if it will apply enough load to accurately guage the battery.

I have a load tester in my garage (an old one)
while it reads the current of both the charging system and battery under load test it draws a heavy current amout
(approximately 60 to 80 amp) and will rapidly tell if a battery if failing
if you dont have one its better to take it to a garage and having it tested.

 

[Octopus]

Is this gadget any good for a battery draw test?

AUTOMOTIVE CURRENT TESTER - CF-02S

What you need to buy is a trickle charger. My brother in law has one for his "occassional" car to stop the battery going flat

 

[gnuuser]

What you need to buy is a trickle charger. My brother in law has one for his "occassional" car to stop the battery going flat

murdoch is correct
a trickle charger will do the trick by keeping a maintenance charge going when needed
this will help a lot when the car isnt being used for a while

 

[telectrix]

best place for a merc C class:

 

[PEG]

Mercs rep has gone in the last 15 years,only ones worth having are G Wagens,large commercials and very top of range. I remember a technician at Portmans telling me the ML's were sometimes just unfixable electrically. Just like the tide of blinged up £90,000 Rangerovers i happen upon,with faults you'd never get on a 20 year old Mk 1 escort...it must be Ms Merkel scowls so...:coolgleamA: