View Full Version : How long run stock stereo on battery?

03-18-2010, 11:57 AM
Been wondering about this...

I have an 08 outback with the Kenwood stereo (6 speakers, amp, and no sub.) and the interstate marine cranking battery. How long do you think I can play the stereo at a descent level before it would drain the battery? I would like to have an idea before I jam out on the lake for 2 hours without restarting the boat. Ballpark numbers is all I'm looking for.

03-18-2010, 12:17 PM
There's a lot of variables involved, mostly how much power the amp draws, the condition of the battery and the level of play and are you fully recharging the battery between plays. The harder you work the amp the more power it will draw. Personally i wouldn't be caught dead with a stereo/amp setup and no second battery to ensure i get home.

03-18-2010, 12:32 PM
I always have a marine jumper pack fully charged in the boat just in case. I only have one battery so the jumper is a must!!! I have not killed my battery yet from just floating and listening to tunes.

03-18-2010, 03:05 PM
if your playing cd then start every couple hours if its an Ipod should not seem to matter much. I never had mine drain down, but the jumper pack is alway a sound idea

03-18-2010, 03:25 PM
I tested this theory last year because i wanted to know. Basicaly you just start in the AM turn it up to what ya want and let it play. Thats the only way to truly know with your set up. Sure it takes a bit but you know for sure. Last year mine went for 13 hours with the cabins and the 700.5 playing with the sub on. I kept it at a decent volume as not to piss off my neighbors but i worked in the yard and garage all day and let the jams go.

The sub shut off and thats when i knew the battery was weak.

03-18-2010, 03:34 PM
I don't think the question was how long the music would play but how long he can play and still get the boat started.

03-18-2010, 04:06 PM
Cool, thanks guys. I think my battery died over night because yesterday I tried turning on the stereo and nothing... had no power to anything. I would say that I played about 4 hours worth of music on it but most of that time was 30 degree weather over the winter. Now, I have no idea how charged the battery was when I bought the boat and I'm hoping it just wasn't fully charged. Weird thing is that when I played the stereo the other night it seemed fine but then the next day I went to turn it on and it was completely dead.. I would think there would be signs of it dying. hmm..

03-18-2010, 04:07 PM
I guess it would be a more technicall question. How low can the volt meter go before the boat wont start?

I defer to the electrical gurus. for 40 bucks buy a jumper.


03-18-2010, 07:12 PM
Turns out the battery is not dead. I have power when i turn the ignition to the "on" position but none of the accessory switches are getting power. No blower, stereo, nav lights etc... What gives? Think it's a fuse somewhere?

Thanks gents.

03-18-2010, 07:46 PM
ahh, just figured it out. It was the thermal circuit breaker that had popped out.

03-18-2010, 08:02 PM
More than likely the battery is close to dead, in fact i'll bet you put a volt meter to it it'll show between 10-11 volts. Just enough to power the lights and stuff but not enough to power the stereo. You should be trickle charging batts over the winter so you have a full charge when going out.