[arimaBOATER]

Hi Would like some info on boat batteries... I have 2 batteries & a PERKO switch [RED with BLACK HAND DIAL] It can go to OFF ONE TWO ALL My battery charger has an auto shut off so it will not over charge a battery. Over charging will destroy a battery. Just wondering when trolling for hrs. & hrs can the alt. from the outboard over charge a battery ??? Is it best when trolling to keep PERKO to ALL or is it best to switch to ONE for a few hrs then switch to Two for a few hrs? Noticed my older battery posts[main battery] were very "HOT" to the touch... I tightened wing nut [pos] as it was alittle loose... My AUX battery is newer INTERSTATE MARINE/RV & I like the idea it does not have wing nuts but rather normal nut so they can be tightened with a wrench... A little mixed bag of battery ?'s hopefully can get some light on the subject. When I put charger on old battery needle went to very low indication... I did not leave charger on though as these Hot to the touch battery post made me leary... about this battery... 2 mos ago I added quite abit of water to bring levels up [this battery is 2-3 yrs old.... other battery only 3 months old.

 

[Bsearunner]

I have two batts. too with the Perko switches. I run with battery one when cruising, when fishing I go to battery two because of all of the electronics. So if I drained bat. two I have bat. one to get me home.
I never run on all, if one bat. is dying your alt. will work to hard, constanly trying to charge the bat.
Plus it can drain your good bat. Go to all when both batts. are low so you can start your engine.
When I get home I have two - 2 amp. bat. chargers with over load protection, this keeps my batts. fully charged when I head out. ( Can. Tire - "Elimminator" - 50.00 each, they do come on sale for 25.00 )
Try testing your bat. that might be dead with a volt meter, it should read over 12 volts and with engine running it should read over14 volts. Then the bat. is healthy. If your batts. are weak I would get 2 new ones, you'll feel better out on the water.

 

[arimaBOATER]

Bsearunner Thanks form your helpful info. I am going to buy a new battery in the next day or two. Your right I will feel better to have two batteries that I can trust. My home charger is auto shut off so it will not over charge battery I think it's 6amp. I assume the alt on the outboard is also using a smart charge as I may troll for 6 hrs & use only the fishfinder which uses very little power. [ Do not want outboard to over-charge battery ] If a battery is treated ok we can get 3 or 5 yrs use I would think.

 

[blackdeath]

Unless your charging system is not working correctly it can't overcharge your batteries. Your main battery is used for cranking the engine and that is all it is used for. When the engine is running, all the power that your boat is using is being supplied by the alternator, including what ever is required to maintain the batteries state of charge. I think most charging systems that are required to maintain dual batteries and operate a lot of electronics will use an alternator that is of sufficient amperage output to maintain what ever the system requires with out damaging the alternator, as long as the batteries are not hooped and require excess charging from the alternator or extra accessories have been wired into the system that could cause an overloading condition.
Batteries need to be fully charged when starting out, as alternators are not meant to charge a battery rather they are meant to maintain a batteries state of charge. In other words it is not recommended to kill your batteries and then rely on your alternator to charge them back up. Thats what they make battery chargers for. Isolating your batteries with the switches you are talking about simply ensures that if your main battery is full charged and can produce enough current flow to get your engine started, you will not be left out on the water with two dead batteries.
Testing your batteries is an important part of the whole scenerio. There are a few different methods for battery testing and they must be done correctly to determine if the battery is any good for service or not. Testing varies for different types of batteries. I'm not going to get into it here but unless you know what you are doing, your best to let a real mechanic do it for you because they will have all the correct methods and tools to do it right. Just because your voltmeter says you have 12 volts means squat. Your battery needs to beable to supply sufficient current flow for a set amount of time to enable the starter to crank the engine over fast and long enough for it to start. A load test is what determines it's ability to do so. In order to do a proper load test the battery must be fully charged. Proper Battery testing will tell you if it can supply sufficient current or not. Loose or corroded terminal connections cause resistance in the circuit, resistance causes heat. Some heat is fine.

 

[arimaBOATER]

blackdeath Thanks for the added insightful info!!! Learned alot from you guys ... very much appreciated. Just yesterday moved the two batteries out of each corner & put them side by side where the main big gas tank was. I use portables & just did not need a big tank as we just fish locally & like for 6 or 8hrs... A Yamaha 40 4 stroke is good on gas & more so at trolling speed. Now I have plenty of room to get at the batteries as the side storage was kinda cramped. Also took off the wing nuts & put regular nuts with a lock washer & now I can keep connections tight. Built a good solid battery frame & straps so batteries will not move about. Also put them high enough should a wave or two come into the boat & they are in cases also. Should say also bought a new rv/marine battery Interstate Norm Miller's co. so now with you guys info I feel alot safer & know more about keeping care of batteries...charge proper use procedures... eace: