marine battery

[russelln114]

Hello guys. This is my first post. I just bought a boat and trailer off a guy and i have a question about the battery. First i know nothing about marine batteries. I don't know what the voltage should be when tested fully charged. I measured the voltage when i brought it home and it said 12volts. It is a 12v battery so does that mean its fully charged? What kind of charger do i needto charge it? How long do i charge it? What setting should i use? When do i know when it's fully charged? As you can see i'm pretty dumb about this so i need lots of help.

 

[dieselcat]

Re: marine battery

First of all welcome to Iboats.Lotta good people on here with very good info.normally a fully charged 12V battery will be around 13 volts or little more.

 

[tx1961whaler]

Re: marine battery

Hello guys. This is my first post. I just bought a boat and trailer off a guy and i have a question about the battery. First i know nothing about marine batteries. I don't know what the voltage should be when tested fully charged. I measured the voltage when i brought it home and it said 12volts. It is a 12v battery so does that mean its fully charged? What kind of charger do i needto charge it? How long do i charge it? What setting should i use? When do i know when it's fully charged? As you can see i'm pretty dumb about this so i need lots of help.

Here:
http://www.ehow.com/how_2224421_charge-car-battery.html

A boat battery is pretty much the same as a car battery.

 

[Barnacle_Bill]

Re: marine battery

See if this also helps

 

[mike343]

Re: marine battery

Just measure the voltage on your car/truck battery. Should be the same and gives you a calibration on your multimeter. A fully charged 12v lead acid battery should measure 12.7v at no load. when being charged you should see 14.0v.

 

[Silvertip]

Re: marine battery

How long you leave it on a charger depends on the charger. A good quality smart charger can be left on indefinitely. Once the battery is charged the charger goes into a maintenance mode and as such becomes simply a trickle charger to keep the battery topped off. Read the instructions that come with your charger if you buy a new one. A battery is called a battery because it is a "battery of cells". In the case of a 12 volt auto/marine battery, there are six cells each of which provides 2.1 volts. 2.1 x 6 = 12.6. Therefore a fully charged battery measures 12.6 volts.

 

[russelln114]

Re: marine battery

Hey guys i went out and bought a battery charger today. I have attached the instructions (charging stages). Can someone tell me how to use this? Can i let this pluged in all the time. What should i be seeing as far as voltage on the screen while charging? Any help would be great. Thanks.

 

[smokeonthewater]

Re: marine battery

set it to auto.... if there is a 6/12 switch set it to 12.... plug it in and forget it.... your instructions state that after charging it will automatically go into float mode which is for maintaining a battery during storage

 

[Fisherball]

Re: marine battery

Never use a car battery on your boat. Auto batteries aren't built to take the physical abuse from a boat. Marine batteries have thicker, stronger lead plates, case is heavier duty, etc. A boat will rattle a car battery to pieces.

 

[bruceb58]

Re: marine battery

Depending on the charger, I may or may not leave it connected indefinitely. Sounds like this may be a Harbor Freight Charger. Not sure I would leave that one on 24/7. It may be just fine but I would monitor the battery water and temperature the first time I left the thing on it overnight.

If you do want to leave it on all the time, get one of those 24 hour timers and let it turn on for 1/2 an hour and off for 23 1/2. The first time you attach your charger turn it just past the off then manually turn it on so it first charges 24 hours. Then every day after, it come on for 1/2 an hour.

 

[TerryMSU]

Re: marine battery

I was told (by someone who should know) that AGM Batteries have a slightly different change characteristic. I can't tell you the details, because mine uses an AGM specific battery charger. High end boat batteries, especially those for trolling, often are AGM batteries.

TerryMSU

 

[russelln114]

Re: marine battery

Well I looks like the battery is fully charged. The battery indicator shows full and it has switched itself to float. That brings me to my next Question. The battery is an ever-start marine with 75amp hours and 100 reserve capacity. Will this be enough to use with a 12v 50lb thrust minn kota trolling motor. I will be using the trolling motor exclusively as i fish a lot of trolling motor only places? The boat is light weight. I would say that with gear and 2 on board I'll be close to 500lbs.

 

[bruceb58]

Re: marine battery

Is it a deep discharge battery? My advice is never let the battery get discharged beyond 50%(about 12.0V). The life expectancy of batteries discharged beyond that point go way down,