Bed Outlet Time To Drain Battery

hey guys, I was wondering how long you think I can run just a couple things out of the bed outlet ( boom box and phone charger ) small stuff, before it would drain the battery to a point where we couldn't start the car.... i'm planning on using it for the boom box for like an hour to an hour and a half this afternoon in the barking lot before a Rush concert. Thanks..

If you think I should, we can run the truck a little to keep the battery charged, but it shouldn't be a problem I don't think...

Thanks for the help

 

Bump!

Would love to know this as well, planning a camping trip next weekend and will be running a sirius radio out the back.

 

You could always buy a battery tender. I dont think they cost too much. Which is designed to shut off and save enough juice to start the truck.

 

different things will draw more or less power from the battery and a slower or faster rate. taking the chance of my truck not starting isn't something I care to fuck with...just run the truck for 5ish minutes every 30 mins or so just to be safe...thats what I would do anyways...

 

+1. I've been on camping trips where someone with a truck wants to play the radio... they just start the truck ever 45 minutes or so. Seemed to work pretty well, we ran it for 3+ hours that way.

 

Batteries are rated in terms of Amp-hours (A-h).

A battery rated for 100 A-h can supply 1 A for 100 hours, or 2 A for 50 hours etc. Multiply time (in hours) by load (in Amps) and make sure that the result is less than the rating on your battery.

As batteries get older I would have to assume that the capability of the battery to supply load for long periods of time diminishes.

I have run the strock radio with my CB on for hours at a time without an issue.

OP, if I were you, I would not be worried about the boom-box draining the truck battery. Just don't run the truck lights or have the heater fan running.

 

Hmmm. I think I just fed you a line of BS. I think my explanation is more applicable to deep-cycle batteries, which would not necessarily be relied upon to give cranking amps after running accessories.

Here's a useful link: http://gbindustrialbattery.com/Battery_Options/AH_Ratings.html

I would still not be worried in your case though.

 

If memory serves, car batteries have a "reserve capacity" rating in minutes. Usually around 100 minutes. This is designed to run the car in the event that the alternator stops charging the battery. Again, if I remember right, they are rating that amount of time based on 25 amps current draw. You'd have to convert the 120 volts draw you have to 12 volts to calculate that out, but I think the max draw on the bed outlet is around 4 amps at 120V, so around 40 amps max at 12 volts? If you have a boom box that pulls a couple amps at 120V, then the battery is going to be flat in about an hour and a half with no other draws running, like interior lights for example.

I think I've got that right. Hope it helps.

A friend of mine has a multi amp system in his Jeep that will flatten an Optima red top in around an hour at moderate volume. I have no idea what kind of amp draw that is.