how fast will this eat a battery?

[Rocks]

I have one of those power inverters that I can plug into my cars cigarette lighter and run 110/120 volt electronics. How fast would a small amp like a fender rumble 15 or a line 6 15 watter eat up my car battery? I'll have to check under the hood to see what its cold cranking amps are but I'm assuming its not a small battery (I drive an '86 Fleetwood Brougham 5.0 liter) I'm just curious about how long I could play without having to worry about the car not starting from a low battery. Any idea how to guesstimate it?

[T-Bird]

Hi.

Way, way too many variables involved to calculate the time with any accuracy.

With the information You have provided, my semi-educated guess would be between 10 and 30 minutes.

Just buy a separate battery to be used with the inverter.

Regards
Sam

[oniman7]

Actually, I'd buy a small headphone amp instead if you're the only one who needs to listen to it. Dean has one for $70 or so if I remember. Would be much less equipment.

I know that doesn't answer your original question, but I'm not able to.

[skychief]

impossible to predict without knowing the power rating of the inverter. If its below 300 watts, you could likely run your Rumble 15 for 6 - 8 hours on your car battery. If the power rating of the inverter is higher, then of course that time would decrease. Dont worry about cold cranking amp rating of the car battery---that just tells you the maximum current that the battery puits out. You likely wouldnt ever need 2% of that kind of power to run the inverter. Hope this helps.

[ggunn]

Originally Posted by Rocks

I have one of those power inverters that I can plug into my cars cigarette lighter and run 110/120 volt electronics. How fast would a small amp like a fender rumble 15 or a line 6 15 watter eat up my car battery? I'll have to check under the hood to see what its cold cranking amps are but I'm assuming its not a small battery (I drive an '86 Fleetwood Brougham 5.0 liter) I'm just curious about how long I could play without having to worry about the car not starting from a low battery. Any idea how to guesstimate it?

In general, you don't want to use a car battery for stuff like this. Car batteries are designed to provide lots of amps for short bursts. Slowly draining them does bad things to their plates, especially the ones they are producing now. Leaving your headlights on and draining your battery completely even just once can significantly reduce the life expectancy of a car battery.

[Dirk Diggler]

Buy or rent a generator.
Dirk