550 M starting issue

I've searched several threads so I'm gonna ask...

For the last month or so I have had to jiggle the ignition switch in the start position in order to get the car to turn over. Most times no jiggling was required but every now and then I'd twist the key to start and nothing would happen. I jiggle the key in the start position and contact would finally be made.

Sunday I go to start the car and nothing. Check the battery and it shows 7 volts. I attach my battery charger and check the next day. I now have 12.5 volts. Go start the car and it would barely and I mean barely turn over. I can hear the solenoid clicking on and off. I checked the battery and it has 10.5 volts, certainly should be enough to turn the engine over.

Jiggle the key and I get intermittent contact but the thing won't turn over. I'm guessing at this point that something is dragging down the battery or the battery is shot, but it's only 1 year old - an Interstate. My charger has a start mode but that didn't help.

Summary:
Possible worn ignition switch
1 year old battery worn out from too many charges
The car is a 99 with 16k miles

Any suggestions?

 

you need a new battery, volts are one thing amps are another...

 

Tom,

an open voltage of 10,5V means the battery must be replaced!
A flat battery exhibits about 11.9V. Anything below that is a dead battery.
To crank the engine you need at least a 50% charge, i.e. 12.3V.

Stefano