Battery question

[samwoolf]

My 2002 polo wouldn't start, and knowing that the battery is on its last legs, I took it out and charged it up overnight. When I put it back in, car started. Later that day though the car again wouldn't start.

Thinking the battery just didn't have quite enough power, I connected up a battery from a Sprinter Van with jump leads. It still wouldn't start. Which made me thing there must be something else wrong apart from the battery, as surely a dying but newly-charged battery in parallel with a battery from a larger vehicle should have sufficient power..

So I called the RAC out - unfortunately I was at work when he came, but my girlfriend tells me he attempted to start the car in the same way I had, by connecting a battery pack to the car battery with jump leads. He also failed to start the car this way.

Then apparently he took a second, more powerful battery, and connected it not to the car battery but to somewhere at the back of the car near the boot. With both batteries connected, the car started.

So my question is - what was he connecting this second battery to?
And does this mean that I just need a new battery? It seems odd that so much additional power is needed to start the car, is something else likely broken too?

[littlepolo]

His battery pack could have been low. He might have simply jumpered the bigger battery at the rear of the car rather than carrying it to the front. Also, he might have tried connecting to the rear bodywork as an alternative ground. It's probably the battery (RAC should have checked it with a battery tester) but have you checked over the ground connection by the battery box?