Starter Cranking speeds up

Thought it was odd.....

Hadn't started the mustang in a couple months. So i had to jump the battery.

It Cranked really slow like i had a dead battery (Normal).... Because ....well.... the battery was dead Of course

But i have had times where if you just keep it cranking slow like that the starter will speed up to the point that the car will start up. This has even happened with me leaving headlights on and not jumping the car.

If it helps i think i noticed my car started turning over like this (Really easy) after i started using Royal Purple....but i could be wrong.

Ive never seen the engine cranking on a car with a dead battery go from the point of it almost clicking to spinning the motor and turning it over.


If it helps i use a trunk mounted Series 31 Odyssey Deep Cycle. And the standard starter.

Wondering if anyones seen this before....Car starts fine when battery isn't drained like normal. Its not really a problem its just starting really easy.

They make automotive deep cycle batteries....it works very well. With the high drain of my stereo i was having problems keeping standard batteries charged. Deep cycle fixed those issues for me. Its worked fine for over a year so far.