Punto with Flat battery

The battery on my M reg Fiat Punto is often flat in the morning, even though it was fully charged the night before (according to the green led on the battery). The only way I have been able to 'cure' this fault is by disconnecting the battery every time I stop the engine.

Sometimes I can hear a click from a relay in the engine compartment when I disconnect the battery and sometimes there is a little spark at the battery terminal indicating a large current is being drawn. However, when I measure the battery current with a multimeter it reads only 5mA.

Reply to
Puntoproblems
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Connecting and disconnecting the battery in a modern car will just about always result in small sparks, clicking relays etc.

Your say you have 5mA current drain with everything off. This looks a little low but is possibly accounted fo by the multimeters realtive high restistance when measuring low currents.

If your are sure you have no current drains, e.g. the boot light is soemtimes common cause of unexplained battery drain, then you could be looking at battery self drain. This happens when sediment, which builds up over time, effectively shorts the bottom of the battery plates out resulting in internal current drain.

In my experience if this internal drain is happening then a battery left disconnected over night will most prabably survive. However when connected the natural car idle load will push the battery too far.

If the battery can withstand 100+ hours disconnected and still be able to start the car then a vehicle electrical fault may be present.

Often the easiest solution is to replace the battery and see what happens. Many battery outlets will test your current battery free of charge. The problem here is that when you have driven to them the battery is quite well rejuvinated by the drive and my well pass their tests. If you can take just the battery, after 24+ hours of standing alone, then the tests results are far more reliable.

Reply to
Nick /////

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