Hi there. My 1989 340 has been running fine for years, however a few weeks ago I accidently drained the battery by reconnecting an old alarm system. I disconnected the alarm and recharged the battery for a good 24 hours and it started fine, I then drove the car from Manchester to Leeds. I tried starting the car only 10 minutes after arriving but the battery had gone flat!! Since then I have jump started it a couple of times and driven fair distances to try and charge it but it still ends up flat. Any ideas on what the problem is? Does anyone think I could fix this myself or is it a garage job? Any help much appreciated as it is a pain jump starting my car every time I want to drive somewhere!
Cheers, Jim.
Battery problems
- broken
Hi there Jimtech,
I have to agree that on the face of it you have suffered 'terminal' battery failure.
You say your car has been running fine for years - which suggests that the battery is also some years old. 'Modern' batteries tend to perform well for a period of time and then 'just die' (completely) rather than soldiering on with repeated charges.
The fact that your battery is flattening so quickly suggests that either:-
Your battery charger is faulty, or you have a massive load when connected to the car causing it to drain very rapidly, or your battery is managing to hold a 'surface' charge only. Even if you had suffered alternator failure a modern battery in good condition, and with a full charge should easily cope with a Manchester to Leeds run. (assuming no headlights or heated screen loads).
Before condemming you battery however, you need to determine the actual cause of the problem. To do this you really need a multimeter but you can make some simple checks without. With the engine running switch on the headlamps and increase the engine speed - if the alternator is working you should see the lights brighten as you rev the engine. If you have access to a multimeter use it to measure the voltage across the battery with the engine running - it should be somewhere around 13-14 volts. (12v or less and the alternator is probably at fault, 12-13v the alternator brushes are probably worn, 14.5v and over and the voltage regulator is faulty).
Another thing you can try is to charge the battery and fit it to the car without connecting the earth lead. Leave the car parked overnight (or 24Hrs if you can) and then connect the earth lead and try to start the car. If the battery has gone flat (with out being connected to the car) then it is almost certainly faulty. If it has held a charge however there may be a high load problem on the car somewhere. You then need to see if the battery will sustain a light load. With the battery off the car and fully charged, connect a low wattage bulb across it (sidelight bulb for example) and leave it connected overnight. If it is still alight in the morning the battery is holding more than a surface charge and it points to a car problem. If the battery has gone dead - you have a faulty battery (or it wasn't charged in the first place).
The most probable problem is a 'dead' battery - but you do need to make sure that the alternator is in good fettle. (usually an alternator not charging would bring on the ignition light (unless the bulb has failed).
Hope this helps a little - Mac.
I have to agree that on the face of it you have suffered 'terminal' battery failure.
You say your car has been running fine for years - which suggests that the battery is also some years old. 'Modern' batteries tend to perform well for a period of time and then 'just die' (completely) rather than soldiering on with repeated charges.
The fact that your battery is flattening so quickly suggests that either:-
Your battery charger is faulty, or you have a massive load when connected to the car causing it to drain very rapidly, or your battery is managing to hold a 'surface' charge only. Even if you had suffered alternator failure a modern battery in good condition, and with a full charge should easily cope with a Manchester to Leeds run. (assuming no headlights or heated screen loads).
Before condemming you battery however, you need to determine the actual cause of the problem. To do this you really need a multimeter but you can make some simple checks without. With the engine running switch on the headlamps and increase the engine speed - if the alternator is working you should see the lights brighten as you rev the engine. If you have access to a multimeter use it to measure the voltage across the battery with the engine running - it should be somewhere around 13-14 volts. (12v or less and the alternator is probably at fault, 12-13v the alternator brushes are probably worn, 14.5v and over and the voltage regulator is faulty).
Another thing you can try is to charge the battery and fit it to the car without connecting the earth lead. Leave the car parked overnight (or 24Hrs if you can) and then connect the earth lead and try to start the car. If the battery has gone flat (with out being connected to the car) then it is almost certainly faulty. If it has held a charge however there may be a high load problem on the car somewhere. You then need to see if the battery will sustain a light load. With the battery off the car and fully charged, connect a low wattage bulb across it (sidelight bulb for example) and leave it connected overnight. If it is still alight in the morning the battery is holding more than a surface charge and it points to a car problem. If the battery has gone dead - you have a faulty battery (or it wasn't charged in the first place).
The most probable problem is a 'dead' battery - but you do need to make sure that the alternator is in good fettle. (usually an alternator not charging would bring on the ignition light (unless the bulb has failed).
Hope this helps a little - Mac.