What's the longest a car can sit without running before its' battery needs a jump?

[severous01]

just go buy one of those little solar panels and put it on the dash, wire it into the cig lighter or put a cig adapter on the end...

at 2 amps all day it dont matter how long it sits there, it'll always be charged.

to answer your question, you'll be doing more harm that good by just starting it up and letting it run for 10 min. it takes more than 10 min to recover from starting the car and start actually charging the battery above use from starter.

there are several voltage maintainers and small chargers for home/garage use at walmart or autozone.

[Yaris Hilton]

Originally Posted by severous01

it takes more than 10 min to recover from starting the car and start actually charging the battery above use from starter.

7 seconds is an often quoted figure given by those recommending shutting off the engine at stops for fuel conservation. I don't know how that was determined, and I'd imagine it differs from one car to another, but surely it doesn't take 10 minutes for the alternator to replace what the starter drew if the engine starts normally quickly. People who mostly drive short trips would quickly have their batteries run down if that were the case.