Worn out, low electrolyte, a draw (something left on) alt not charging. You need a cheap voltmeter to check (about 5.00 from auto parts store)
dead cell in the battery or something is on that is pulling power from the battery.
Could it be the 6 year old battery itself?
if you are experiencing this with your own car, it may be a drained battery.
Could be the battery is drained or bad. Could be battery connections at battery and or starter are dirty and or loose. Could be starter solenoid is bad. Could be starter is bad.
Need to see how many amp or watt hours your battery is rated for, many batteries are up to 100 watt hours.your cell phone may hold 1 or so watt hours to give you a comparison. A car battery could maybe charge your phone 500,times before its drained.
Each and every time a battery is drained dead it does harm the battery somewhat. However if it was only run down once, then do not worry about it. It has taken some life out of the battery but it is still good and should last years more.
Until it runs out of gas. * Until the battery is drained.
Not with out being attached to a battery charger. On a 10 amp charger in 8 hours it will charge enough to start the car, allowing the battery is god enough to charge
You may still be able to charge it up.
There could be many reasons as to why this car will not start up. The battery could be drained, the starter, starter solenoid or alternator could be going bad, or there could be an issue within the fuel system.
check if your lights are still on that drained the battery
You either have a corroded or loose battery cable connection at the battery, a defective or drained battery, defective starter relay or starter.