Battery Situation

[Nauti Jenks]

Ok, so it was birthday weekend on the water this weekend and i just completed my stereo install of 4 new speakers amp and head unit so of course had to get my moneys worth on the first weekend with it. Well both friday and saturday my boat died and had no turnover. Granted they were plated for 5 hrs+ straight. So im wanting to add another house battery for strictly the radio. Is the best way to do this is run parallel with the other house or should i keep this battery by itself?

Also i bought a brand new starter battery this year but for some reason i can have it charged all week and then it won't even turn over to start. Could this be a connection issue or could maybe my charger be done? My house battery seems to charge which makes me think the charger is working.

Any input is much appreciated and it has already been an awesome year of boating in Kentucky!!

[pascavone]

I think your new stereo or amp is not turning off.

There is a pink wire on those that keep the preset radio memory active, most wire that to the red power wire, which goes off with your boat battery switch.

adding another battery is not the problem. your two batteries will run a stereo and amp for 24 hours.... (unless you have a huge sub-woffier, or a 12v inverter for a TV or something.

unplug the boat from shore power and see what goes dead and how fast.

a car radio draws abour 40 milamps.... which is nothing.
for example, my carbon monoxide dector was expired and was drawing 400 millamps and killed my battries in a week.

I think your issue is not the run time of the radio.

[Nauti Jenks]

My amp turns off when the radio turns off, i ran it for probably 8 straight hours on friday night and was fried the next morning. I didn't run it on both batteries just the house battery so i could try and have my other battery to start it but like i was saying the starter battery is not holding much power for some reason and its brand new this season. im going to check the connections this week. Im hoping its not the charger but i still think im going to parallel another battery with the house just for more since of mind to me each weekend. I struggle with the which battery to keep the shore power charging each week because ive read if you keep on both it doesn't charge either, not sure if thats true or not.

[ImRich]

I'd like to suggest that you get yourself a multi-meter and then take a little time to learn how to use it.

This will allow you to check the current draw of individual items, as well as measuring total current draw from your battery (But don't try to start your engine with the meter inline unless you get a shunt that can read hundreds of amps, which most of us don't need).

Then check the current draw at your battery with everything turned off, and see if your batteries are being drawn down. Then you can also check each piece of equipment, one by one, to see how much power each is drawing when on, or more importantly, when off.

Good luck!

[pascavone]

you should never run the boat on BOTH..... this will fry the starter.

run one battery when starting and moving, and them switch to the 2nd when docked.

then you can limit which curcuit is drawing power.

the charger and alternator are wire to charge both, reguardless of the battry switch setting.

[Nauti Jenks]

Thank you all for your input, i will look more in to this and see what i find out. Just wanting to make sure i don't get stuck without a battery again if playing music all day long. That and the fridge i believe are the only things taking power when im anchored out.

[ss3964spd]

If the fridge was on that's what used most of the power from the battery.

Originally Posted by pascavone

you should never run the boat on BOTH..... this will fry the starter

Incorrect - if the batteries are wired in parallel as per normal boat battery wiring practices.

Assume two batteries, each is a 12v, 600 Amp hour battery. If you wire these two in parallel the voltage remains the same at 12, but the capacity is doubled to 1200 Ah.

If you mistakenly wire them in series the voltage doubles to 24, but the capacity doesn't change at 600 Ah.

Dan