Boat battery issues

How old is the battery, have you been maintaining it with a trickle charger monthly ?
Is it gel cell or acid with fill ports ? You will need a cheap battery hydrometer from Pep Boys, and a trickle charger if your a boat owner.
Don

x2 on the trickle charger...I have found them cheap at pepboys and biglots randomly and they can easily be mounted in your house with a nice, long, all weather cord out to the boat to keep it charged up.

I dont know of any way to test your battery without taking it in to a shop...maybe charge it from a trickle charger and then hook up a volt meter and see if if holds at 1/5/24 and 72 hours

Dont ever buy acid batteries. Imo, they arent nearly as good as gel

And you should always hook up a 10amp battery charger to your batteries if possible when sitting.

A battery lasts the longest when it doesn't lose half its charge.

Quote from Dan

I'm assuming that the boat battery works the same as car as far as getting charged ie. there's some kind of alternator in the motor. In this case it would seem logical that leaving the boat running for half an hour should charge the battery enough to be able to start the motor in the future. This is not the case, a week later the battery doesn't have enough juice again to start the motor.
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Did you run the boat at idle for a half hour?

I'm not an expert by any means but I believe that some motors don't charge the battery at idle RPM because the current output of the alternator is dependent on the flywheel speed.

Quote from Dan

What does a battery hydrometer do?

Checks the electrolyte/ water for charge, take a quick pic so I can see if it's a gel cell. If it is you don't need a hydrometer just inexpensive volt/amp meter. I think you have had the boat for 1 1/2 years ?

D

double check to make sure everything on the boat is turned off. we see it happen at work with cars all the time and ive done it with my anchor lights. second depending on how long the battery has been sitting without a trickle charger it will lose juice but IF the battery is still in good condition a charge will do it. Like stated before allowing it to run dead and then charging repeatedly isn't good for the battery. To check the alternator you can measure voltage at the battery with the outboard off then start the motor and measure voltage at the battery again. We commonly (again in cars) see acid batteries go in 2-3 years, but I had one in my boat when I bought it that was 7 years old and still tested good. lastly I know sears can test a battery if you want to hassle with bringing it in to them.

The battery should be labeled with both the type and the date it was manufactured. If its too tight to get out it might be to tight to see. I have heard from a few people that marine batteries only last a few years.

To test it you can buy a trickle charger and charge it until the unit says the battery is full you can either see if the boat starts or use a volt meter to check if the battery is actually full. Some boats have one (volt meter) built in with the fuel gauge but not all. Thats another thing that might be a nice addition. They may not seem all that useful until that day when you go out and your engine wont start and you start trying to figure it out without one. Dont ask how I know.

Sounds like a bad battery. All batteries have a date code on it. look for four digits which should tell you the week and year of production. this will tell you how old the battery really is. these numbers should be somewhere on the label of the battery.
With a volt meter you can measure the voltage at the battery terminals with the engine on voltage should be about 14.4V dc.
another test is to turn on the engine and unplug the battery while the engine is running if it turns off bad alternator if it stays running bad battery.This used to work on older system not sure if it will work the same on newer systems as they could have electronics that would shut down the engine if the battery is diconnected.

Most boats down here have flooded cells

[quote='jcmeng','http://spearfishing.world/forums/index.php?thread/&postID=48279#post48279']
another test is to turn on the engine and unplug the battery while the engine is running if it turns off bad alternator if it stays running bad battery.This used to work on older system not sure if it will work the same on newer systems as they could have electronics that would shut down the engine if the battery is diconnected.

This will fry the diode in the alternator the same as turning the battery switch to off with the motor running,
no load for the alt. It does work with generators
Cheers, Don

Dan, your battery is toast. Boat batteries always need to be topped off with a charger to keep them in good shape, a on board charger is ideal as it will give it a slow charge and maintain it. Also a overlooked problem is the terminal both at the battery and at the starter, these should be properly soldered NOT CRIMPED. If all fails ill be glad to take that RIB off your hands

Dan that charger looks fine. I like the option of 10 or 2 v charges so you can also do a quick charge but it is not needed. I would say your best bet is hook the battery up to the charger for one day every thirty and then you won't drain the cell but it will always be juiced

Dan, do you have a 2 battery set up? ie one for starting the motor and one for the blender, 300 watt stereo amp and disco lights ? appropriately call '' House Battery''.

Cheers, Don

The battery tender will be great to keep the battery in fully charged trim. I would use it if the boat is not used for a two week period. In time you will need to get into the battery box to clean and secure the connections, it is just one of many things a skipper has to do. I would use the Battery Tender the night before a trip, if you hard wire the quick disconnect make sure you keep the connector dry and salt free. Nothing mess's up a trip more than a outboard that wont start at the ramp, while all the New Yorker,Conn and Canadian snow birds stand there in black socks, Bermuda shorts and street shoes, point and tell each other dumb shite like ''he flooded it''.
Do you need a jump start ? Do all your maintenance well, back in your drive way. When you hit the ramp with your A team crew your on a mission to kill.... fish of course.:thumbsup2:

Cheers, Don

Quote from japsw

Dan, your battery is toast. Boat batteries always need to be topped off with a charger to keep them in good shape, a on board charger is ideal as it will give it a slow charge and maintain it. Also a overlooked problem is the terminal both at the battery and at the starter, these should be properly soldered NOT CRIMPED. If all fails ill be glad to take that RIB off your hands

A very accurate post of what I am thinking. Although professionally crimped works just fine.