Hope it helps
Lr
It could be anywhere from an hour or two to indefinitely. It all depends on the reason. If the alternator has completely stopped charging the battery it will be an hour or so. It's possible that it is still charging though but isn't producing enough current which causes the indicator light to come on. If it comes on and turns off intermittently this would probably be the case.
No one can pull that answer out of their pocket!
There are a lot of factors that can cause the time to vary!
For all you know the vehicle may still be charging with the battery light on, since you did not provide your vehicle information, (Year, Make, Model) then it is anyones guess!
Till the battery runs down. A brand new fully charged battery will last a few hours longer than one that's been in the car for three years.
It has to do with the state of your battery and if you "have" to run the heat or A/C radio head lights and things like that. A good battery will last a few days unless you "have" to have. Then it will only be a few hours.
Best to assume not far, because some alternator faults will make the battery go flat very quickly. If you can, take it straight to a local auto electrician.
Driving at night with lights on and/or the ac will definely shorten your drive time
