kyle0k

My wife drives a 2011 sl63. In the last month it's been colder (40-50s in PHX) and it's been having harder starts. When you press the start button, it barely turns over once, then silence for a split second and then it starts as normal. It's not normally how I would expect a dieing battery to act. From my understanding there are two batteries though. Maybe thats why it sounds different. I also don't have any dashboard lights warning of low battery. I hooked up a trickle charger to it to see if that helps.

Does this sound like a dying starter battery? If it is, it looks like the dealership is my only way to go nowadays right?

kyle0k

I just went outside to check on it and the trickle charger said battery is full. Thats wierd that it only took like 20 minutes. When I tried to start the car, it now turned on without hiccup, but it did sound a bit weaker than normal (slower). Does that still sound like a dying syarter battery?

okbarnett

5 yr old battery? its too old

cal1

Sounds like an old starter battery to me. I think a number of parts places like autozone, o'reilly, etc will test it for free. Replacing the starter battery is easy. You might bust out the manual and see what it has on disconnecting and reconnecting the starter battery. MY SL55 manual explains the whole process starting on page 320.

One caveat is a few systems might need a resynch. My car needs ESP resynchronized and oddly enough the side windows. The procedure is also covered in the manual.