Battery won't hold charge and boot won't open

[Revers]

I have a CLK230K 2001 model. I have never had any problems with it until tyhe last couple of weeks. The car was idle for six months as I was travelling a lot. When I tried to start car a couple of weeks ago the battery was flat. I arranged to have the car picked up and serviced (B) and MOT'd. Everything was fine and the battery was fully charged. The battery is only a year and a half old and within 3 year warranty. I picked car up on Christmas eve and suddenly the boot would not open remotely. I tried the key and it snapped. I used WD40 and now the barrel just goes round and round. Decided I could live without the boot over Christmas and drove to Swansea. Three days later I drove back to London. nearly 500 miles round trip and all fine. I didn't drive the next day but the day after I could not start the car. Battery flat. I called Breakdown and they came and started car with jump leads. Mechanic said that the alternator appeared fine. Drove around and later in the evening the car would not start again. Had to get Breakdown out again and get jump started. Mechanic suggested a dodgy earth wire. I now have jump leads as this is only way to start car. Did book in to garage but snow this week caused that to be cancelled. Any help will be appreciated.

 

[andy27168]

Hi,
Welcome to the forum.
Personally I think your battery is U/S, because if it was left connected on the car for six months it will have deeply discharged over that period, though it seems to be appearing to hold a charge, the deep discharge will have effectively considerably reduced the batteries life and its reserve capacity, and now this cold weather has just finished it off.
You could try to take the battery off of the vehicle and give it as high a charge as possible, for a period of time then drop it down to a trickle for 24 hours or so, and see if this improves things, failling that take the battery back under guarentee but do not mention that it was idle for six months, as they then won,t honour the guarentee.
As a matter of priority get the key blade from your spare key and make sure the the key barrel in the boot operates correctly.

 

[Revers]

Hi. Thanks for the reply. i did try the key blade but it snapped at the end. i can still use it will pliers but i squirted WD40 in to loosen it up and now the key just turns round and round. The battery had been given a full charge over 24 hours when it was at the garage. But I can't get it out. The garage did test it and they said it was in good order.

 

[MBK]

Hi,

Make sure that the battery terminals are connected properly and tight. Other than that i would suggest getting the battery replaced under warranty.

K

 

[lynall]

Depends what the garage tested it with as well, ie a drop tester is pretty crude and not always 100% right whereas as something like a midtronic is the mutts nutts.
A new battery has got to be the cheapest option.



Lynall

 

[Merc Owner 2B]

I have a CLK230K 2001 model. I have never had any problems with it until tyhe last couple of weeks. The car was idle for six months as I was travelling a lot. When I tried to start car a couple of weeks ago the battery was flat. I arranged to have the car picked up and serviced (B) and MOT'd. Everything was fine and the battery was fully charged. The battery is only a year and a half old and within 3 year warranty. I picked car up on Christmas eve and suddenly the boot would not open remotely. I tried the key and it snapped. I used WD40 and now the barrel just goes round and round. Decided I could live without the boot over Christmas and drove to Swansea. Three days later I drove back to London. nearly 500 miles round trip and all fine. I didn't drive the next day but the day after I could not start the car. Battery flat. I called Breakdown and they came and started car with jump leads. Mechanic said that the alternator appeared fine. Drove around and later in the evening the car would not start again. Had to get Breakdown out again and get jump started. Mechanic suggested a dodgy earth wire. I now have jump leads as this is only way to start car. Did book in to garage but snow this week caused that to be cancelled. Any help will be appreciated.

When you say "would not start" do you mean that it would not turn over (crank?) If this is the case then almost certainly it's the battery (although it could be a faulty starter motor, but unlikely).
The battery has to be tested under load using a "toaster". It's important that it's tested properly by your battery supplier or else they'll just give it back saying it's alright. Can you swap the battery with another car for a while?

Could also be a leaking diode in the alternator which is hard to diagnose. Do you have a good auto electrician nearby?

 

[rossyl]

sounds like you've broken the barrel of the boot lock. i would remove the key in any event, and then have it looked at.