battery drain on c200

[satty73]

help i have a 1999 c200 which after being left overnight, would not start in the morning it was just clicking. FLAT BATTERY after a hour of sitting there it had drained further to point where central locking,boot release etc wouldnt work. Took out the battery and charged it overnight it was then left for 24hrs after which we put a battery tester on it and it showed green, after putting it back in the car a friend of mine did a multimeter test which read 0.03 which he told me was fine. But low and behold after sitting doing nothing for 2/3 hours when i went to start the car again it was completely flat again. I know my ignition coils need changing would this cause it to drain and so quickly or do i need a new battery due to dead cells. Please help as my wife uses the car and the nagging and moaning is doing my head in
cheers

 

[MIW615]

help i have a 1999 c200 which after being left overnight, would not start in the morning it was just clicking. FLAT BATTERY after a hour of sitting there it had drained further to point where central locking,boot release etc wouldnt work. Took out the battery and charged it overnight it was then left for 24hrs after which we put a battery tester on it and it showed green, after putting it back in the car a friend of mine did a multimeter test which read 0.03 which he told me was fine. But low and behold after sitting doing nothing for 2/3 hours when i went to start the car again it was completely flat again. I know my ignition coils need changing would this cause it to drain and so quickly or do i need a new battery due to dead cells. Please help as my wife uses the car and the nagging and moaning is doing my head in
cheers

You say that the battery test "showed green" - what do you mean exactly, the battery needs to have the voltage tested "under load" using a proper tester - you could well have some duff cells but still show 12 volts. The multimeter test sounds okay assuming its a 30 m/a drain.

I would check the connections on the starter motor, but it does sound like your battery is finished

 

[M6AJJ]

You don't say how old the battery is, but even so it points to being on it's way out. If it is older than three years, I would change it anyway, particularly with winter coming up.

 

[satty73]

thanks for the replies i have had the car 5 years and have never changed the battery so i shall change it tomorrow and fingers crossed

 

[M6AJJ]

Best of luck, please let us know if it resolves the problems

 

[satty73]

been 24hrs since battery change and all is well thanks for all the invaluable advice

 

[anyweb]

it's very common at this time of year for all sorts of battery problems, especially if the battery is old, it happened to me two years ago, problems starting the car, turned out the battery was (wait for it) 10 years old, no wonder it needed replacing

 

[television]

Rather than keep writing it all out. I will do a special on batteries with the problems encountered for the various models, I could not bare to write it out 100's of times more