Car battery, interior light. How long?

Factual Questions
1

I replaced the battery in my Jeep. Last week I had a new ignition switch put in, as well as had other maintenance performed. The roomie was going to use the Jeep today, and it was dead.

I put the charger on, and she said one of the interior lights was lit. I think she used the Jeep Sunday. Or maybe it was Saturday. I don’t remember. Apparently she’d turned on one of the overhead lights and forgot to turn it off.

Would that really run down the battery between then and now? Or is it possible I have a ‘leak’ somewhere?

2

I’ve drained the healthy battery of a daily driver car all the way down to dead over just a single night with the interior cab lights on.

These new-fangled cars where the interior lights stay on for a couple minutes after you get out are not always helpful; they camoflage the fact you’ve left the dome lights on.

3

I have seen that too, but it depends at least to some extent on the strength of the battery.

4

Oh yeah, that will kill it.

Figure maybe 50 amp-hours for the battery and maybe a 1 amp drain and that’s enough to completely drain the battery flat in 2 days.

A bigger battery may have a bit more capacity than that, and your particular light may have more or less of a current draw than that, but generally speaking, most cars will have their battery killed in one to three days if the overhead light is left on.

5

I’ve had my cabin light on in my Mazda 3 overnight a couple of times and it still started up fine in the morning.

6

You sure it was actually on all night? Lots of cars will kill the lights if left on for more than about 10 minutes.

7

The Jeep is a '99, and I don’t think it’s smart enough to turn its lights off.

I just started it. It will start, but you have to keep the accelerator pressed or it will die. I’ll keep the charger on for another 4-1/2 or 5 hours, and button it up before I go to bed.

8

Interior lights on cars are just plain evil. They’ll drain a charged battery easily within four hours. Headlights will drain a battery in under 2 hours.

I’ve gotten burned so many times leaving my interior light on. I’ve made a firm policy to never turn them on with the switch. I always open a door. It’s just too easy to forget and not turn the switch off.

9

Just wanted to add that I learned the hard way to pull the circuit breaker to the interior light before taking the doors off my Jeep. There’s a little push-button sensor on the door frame to tell the Jeep when the door’s closed and to turn off the dome light.

“Why won’t this stupid battery hold a charge? Oooh, that’s why”

10

I have a 2000 Jeep TJ and when I first got it a couple of times the battery drained after not being driven for a couple of days (like if I was away on vacation.) Long story short, I finally realized (with the help of the Jeepkings message board) that I was turning the key all the way to the “ACC” position when turning off the ignition and the key was still pulling out. No wonder the radio would always pop back on. :smack:

It took about 2 days of not being driven (to recharge the battery I guess) until the battery fully died.

11

I replaced all of the dome and interior lights in my Honda Element with LEDs. They’re much more energy efficient, last longer, and are *much *brighter. I love 'em.

12

When did you replace the battery? You might not have driven it enough since to fully charge the new one.

13

And, similarly, I’ve left one on all night with no ill effects.

14

Around 2005ish, I parked my 198x Celica at a family member’s wedding and left the dome light on. A mere 2 hours later, I needed a jump. I suppose it depends on the battery–that car was an old piece of crap. I still have no idea how old the battery was.

15

I think (but am not sure and cannot check) that my 2000 Saturn SW would not alert me with a double beep if I tried to lock it via remote and the interior light was on.

16

I replaced it over Thanksgiving, I think. And no, the Jeep hadn’t been driven much. But the battery was fully charged when I bought it. (I asked several times.)

17

I’ve had cars with the dome lights on all night be fine, and I’ve had cars go dead in less than an hour while I was cleaning or working on them and left the doors open.

Fuse #3? I laugh my butt off because they actually sell little $20 doo-dads to hold the sensor down when you take the doors off, or you can pull the fuse in even less time for free.

edit: just noticed this:

It may not charge. A drained battery should stay running, having to keep the gas pressed is a symptom of a bad battery. I’ve had that happen twice in my Jeep.

18

But the thing is most of these ‘new-fangled’ cars also turn any & all interior lights off after about 15 minutes from the time the key gets pulled out. They’ll even do it if you’re sitting there with the door open (it obviously doesn’t know you’re there, just that the door might be ajar). My last two, '95 & '04 Pathfinders, do this.

Oh, and yes, leaving just the dome light on overnight can kill a car’s battery.

19

And my wife’s '04 Jeep Liberty doesn’t do this. Ask me how I know :wink:

I agree that some cars are smart enough to do that. But not all & it’s not obvious which are which. Hence my caveat “… are not always helpful”.

Jeep makes a bit of a fetish of not including all the latest & greatest convenience fetures in their products. As the OP is (re-)discovering.

20

It’s a pretty stupid thing for the car makers not to do, because it’s all controlled via the car’s computer, having the dome light stay on after you get in, having it slowly dim-off, having it come on when you press the keyless entry to unlock etc. Which means it’s just a matter of some software code to make it always time-out and not kill your battery…