I was reading an article in this weeks auto express about a reply to an article they ran couple of weeks ago. It was about the amount of call out's the break down services had to flat batterys. to cut a long story short, they mentioned that they see taxi drivers sleeping in there cars with the engine running with the lights on. What part dont they understand if the engines running the battery's charging. They did also mention about the enviroment, with the car running.

I was reading an article in this weeks auto express about a reply to an article they ran couple of weeks ago. It was about the amount of call out's the break down services had to flat batterys. to cut a long story short, they mentioned that they see taxi drivers sleeping in there cars with the engine running with the lights on. What part dont they understand if the engines running the battery's charging. They did also mention about the enviroment, with the car running.

When the Engine is running and the Car is not, the Engine's RPM's at idle are quiet low to force the Alternator produce enough juice (Current). To add, with all the Loads in the Car running like the Lights, etc., the available charge for the Battery to charge is reduced much further. This will only leave the Battery undercharged resulting in Battery weakening in the long run (due to non-reversal of Sulfation on the Leads within the Battery). This is probably what the reply in the above quote meant.