Is the boat stereo a significant drain on battery?

[pzurek]

Hello,
The stereo installed in my runabout is wired to the starting battery and there are two speakers installed. Last weekend when I was out on the lake, I had the radio on for about 20 minutes with the engine off. When my father started the engine (I wasn't paying attention) he claimed that it sounded a little weak cranking the engine and claims that it was because the radio was on. I said there's no way that an FM radio can drain a battery in 20 minutes enough that you could tell a difference when starting the engine. So who's right here?

Obviously this would be easy to test by playing the radio when the boat is trailered in my driveway and then checking the battery voltage afterwards, but if my dad is indeed correct that the radio has a significant drain on the battery, then I don't want to shorten the life of my starting battery by discharging it beyond what is safe.

I'm going out with some friends tomorrow and hope to drop anchor and enjoy the weather with some tunes, and I'd prefer not to get stranded by a dead battery

Thanks for the help.

 

[The Famous Grouse]

Re: Is the boat stereo a significant drain on battery?

20 minutes sounds a little on the short side to produce significan't drain on a battery with a small stereo and 2 speakers. Unless the battery is beginning to fail.

But it depends. Battery drain is a signifcant issue on a lot of newer wakeboarding boats and other boats that are running high-powered stereo systems with multiple subwoofers and a stack of 500 gajiggawatt amps.

It doesn't sound like that's you, however.

BTW, you can't necessairly tell the condition of a battery just by checking voltage. Even a bad battery can measure 12 volts, but the battery needs to be able to deliver that 12 volts at a high enough amperage.

I suspect what might be happening her is that your battery is starting to fail. It's fine for just starting the motor, but put a little drain on it from the stereo and that takes just enough off of it to produce a slow start.

Grouse

 

[windsors03cobra]

Re: Is the boat stereo a significant drain on battery?

I've played the radio with a bible sized amplifier and 4 bigger speakers at a medium volume for 6 hours and had no problem cranking up a big straight six.
Good quality 1 year old Group 31 battery.

 

[seabob4]

Re: Is the boat stereo a significant drain on battery?

I'd have to go with the Grouse on this one. Bring the batt into and auto parts store and have them load test it...even if you think it's relatively new...

 

[iop]

Re: Is the boat stereo a significant drain on battery?

Invest in 2 batt system. Its just makes all the sense in the world no matter how far out you go or what kind ride you have... its the only way not to have that "feeling" when you go to crank over.
I have one expensive deep cycle battery that is for running things when anchored. And I have a diehard that is the one for the chevy 350... 880 CCAs on a switch.

But that 20 mins is a sure sign you need to do something... I have ran the deep cycle for hours with 4 speaker stereo and lights and no problems cranking over the V8.

 

[seabob4]

Re: Is the boat stereo a significant drain on battery?

I DEFINITELY agree with IOP. Down here, on the west coast of Florida, you've got to run along way to deep water. You don't want to get stuck out there with a sh!tty batt. Electrical systems in the salt water world are a MUST!

 

[The Famous Grouse]

Re: Is the boat stereo a significant drain on battery?

Invest in 2 batt system. Its just makes all the sense in the world no matter how far out you go or what kind ride you have... its the only way not to have that "feeling" when you go to crank over.
I have one expensive deep cycle battery that is for running things when anchored. And I have a diehard that is the one for the chevy 350... 880 CCAs on a switch.

But that 20 mins is a sure sign you need to do something... I have ran the deep cycle for hours with 4 speaker stereo and lights and no problems cranking over the V8.

A two battery system is good, but not feasible in many boats due to space limitations in the battery compartment. It's also difficult to justify the expense for many casual lake boaters.

Grouse

 

[pzurek]

Re: Is the boat stereo a significant drain on battery?

Thanks for the responses everyone.

Regarding the battery possibly failing, it is about 2 months old. Tomorrow I will pay attention to how it sounds when I start it and see if it might be developing a problem. Maybe my father wasn't paying attention when he started it and thought he heard something he didn't.

@windsors03cobra: I'll feel comfortable playing the stereo tomorrow knowing that and not have to feel like a dork when I tell everyone they only get 20 minutes of radio time.

@iop: I actually have a deep cycle battery in the other battery compartment but the radio isn't wired to it. Eventually I'd like to move it over. This is my first boat, it's about 3 months new to me, so that will be my first project

 

[109jb]

Re: Is the boat stereo a significant drain on battery?

I think dad just doesn't like your music

 

[QC]

Re: Is the boat stereo a significant drain on battery?

Ultimately depends on the power draw. I have a 1000 watt system and it can eat a Battery. I would be afraid to use it without a two battery system. The Power Amp has a power level cut out, and it trips fairly often which shows that the battery is getting weaker.

 

[windsors03cobra]

Re: Is the boat stereo a significant drain on battery?

FWIW My grandpa god rest his soul was totally anti playing the radio in an automobile and would go as far as to say "it ruins the battery"
At home he was a radio listener but just did not like playing it in the car, maybe it was a car with 4 amp generators thing ?

What kind of battery are you using, group size ?

 

[joed]

Re: Is the boat stereo a significant drain on battery?

I would still have the battery tested. Possibly the charging system is not working properly and the battery is low on charge. Do you have a voltmeter on the dash?
On my boat I run FM radio, VHF radio, fish finder, downriggers and never have problem restarting motor after 4-5 hours.

 

[Doernuth]

Re: Is the boat stereo a significant drain on battery?

Also what kind of battery is it hooked too. Starting batteries are not designed for things like radios. Deep cycle and dual purpose batteries are.

It does make a difference

 

[seasprite88]

Re: Is the boat stereo a significant drain on battery?

If the stereo has Any kmind off memory wire for the time and preset stations it might be draing power while its in the yard. therfore you might be pullin power off the battery all the time.

 

[Stachi]

Re: Is the boat stereo a significant drain on battery?

I think dad just doesn't like your music

aaahahahahaaaa ! good one ! I had that thought to!

 

[mrcool]

Re: Is the boat stereo a significant drain on battery?

My outboard does not charge the battery, so to be safe I bought a lawn tractor battery and use that for the radio only! If the battery go's dead after awhile, so what, I still have my starting battery,,,I just can't play the radio anymore till I charge up my "Radio battery" But I'm not stuck with a dead main battery.

 

[45Auto]

Re: Is the boat stereo a significant drain on battery?

We anchor all the time for 6 or 7 hours with the stock 200 watt 6 speaker system playing the whole time. Never had any battery problem at all.

I know lots of people who've left car stereos on overnight that weren't wired to the ignition switch. Never had any problems there either.

 

[Brewman61]

Re: Is the boat stereo a significant drain on battery?

They do make those gadgets that you attach to the battery- it cuts off the power drain fully if the voltage drops to a certain level, and allows you enough battery to start the motor. Don't know how well they work, but not a bad idea for someone on one battery worrying about accessory drain.
Many stereos draw a little current even when they're powered off, but that small drain shouldn't hurt a healthy battery. Unless it's over a long period of time, in which case- shame on you for not using your boat!

 

[H20Rat]

Re: Is the boat stereo a significant drain on battery?

A starting battery will easily support a single head unit, no amp, for a LONG time. Almost all head units are rated at 10 amps input, and it is almost impossible to sustain anywhere close to that. Average input is going to be in the 2-3 amp range. So given your average 40 amp hour battery, that is roughly 20 hours of runtime.

 

[Mark42]

Re: Is the boat stereo a significant drain on battery?

Add me to the "two battery" group. Boat only has a low power stereo (no booster, no sub woofers), but lots of interior lights. Right now batteries must be manually swapped, but for next year, new cables and a battery switch will be installed.

Now just have to figure out which side of the boat needs to have the weight of both batteries to prevent list.... Probably about 60 lbs between the two. Also have to down grade the listing on the capacity plate again for added stuff.....