Hunter 27 charging system

whatfiero · May 14, 2016

Big stereo usually a power boat thing but it's cool if ya into that they usuall draw a lot power so you will need to figure out usage and keep starting battery isolated for restart if necessary but unlike a gas powered boat the diesel (unless you have electric fuel pump) doesn't need any power to run so running engine with loud stereo will not kill engine if charging circuit can't keep up it should set charge alarm off or start to distort stereo as a warning your drawing too much power to turn down but mechanical fuel injected diesel engine will just keep running along unless altinatotor over heats that can cause a fire

Crazy Dave Condon · May 14, 2016

Have been taking care of a 1981 model for Boy Scouts. Use one battery solely for engine only and the other for anything else. I did install a battery charger.

Stu Jackson · May 14, 2016

johnm5858 said:
the amp manufactuer says it draws 15-20 amps normal use.

Is it a car stereo or something that could rock an entire house?

If it's a car stereo, he was lyin' to ya. Car stereos usually use 1-2 amps max when running at HIGH volume.

Your other questions are basically: what's Electrical Systems 101 for boats?

Buy a book, really - Charlie Wing's is very good.

You could also start here, good luck:

Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html

Stu Jackson · May 14, 2016

Also this:

Hitachi Alternators 101 http://forums.catalina.sailboatowners.com/showthread.php?t=166123 This comes up so often on other boating forums...

dlochner · May 14, 2016

How big is the house battery?

A group 24 Battery has around 80 amp hours available. Keeping the state of charge above 50% means that you have about 40 useable amp hours. After 2 hours of the stereo alone, you will reach 50% SOC assuming that you started with a battery that at 100% SOC.

Remember sound travels very well across water. Be sure that your neighbors in the anchorage share your musical tastes.

whatfiero · May 14, 2016

A guy in my boatclub has like 2 amps and big speakers kills 2 group 31 in like 30 min with engine not running he upgraded altnator to 125 amp and still can't keep up

whatfiero · May 14, 2016

He also had an altnator fire scary stuff but it was a rebuilt modified alt.

Benny17441 · May 14, 2016

To answer your question that amplifier will deplete two average size batteries in under 4 hours considering a load of 15 amps at 12V. Your alternator may be rated at 35A but in real world conditions you would be lucky to get 20A and much less at idle speed so no, it will not be able to keep the batteries charged. The larger an alternator is the more horsepower it consumes; as your single cylinder Yanmar 1 GM produces only 6HP the alternator cannot realistically be upgraded. You may have two alternatives; 1) upgrade to a huge size battery bank or 2) carry a portable generator to drive a 120V sound system. Are you sure you wanted a sailboat?

whatfiero · May 15, 2016

I grew up in 80's and walked around with boombox with like 10 D batterys makes a lot noise for long time but I like the little Bluetooth speakers got suction cup on one sits on cabin top other in cup holder cockpit

Benny17441 · May 15, 2016

Yes now days there are very high quality Bluetooh speakers that provide a very good sound at very low power usage. No need to impress your taste in music upon neighboring boats which may or may not appreciate it.

dlochner · May 15, 2016

If you would like to keep your neighbors happy and friendly, get a set of bluetooth headphones. Solves a couple of issues: power consumption and improves social life with neighbors.