Gary C

I have a real stupid question. I have 2 batterys. What is the correct position to have the battery switch in? Do you alternate between 1 and 2? Do you use "all" I'm curious, because somtimes I use all and somtimes I alternate. And I don't really know the right way.

Turbojack

I alternate. That way I keep both batterys charged up. If you use both then if one battery gets an internal short or drained down, it will take the good battery down with it & you will be stranded with 2 dead battery.

Audiofn

It depends on the state of the batteries. For exampl. If you are out at the beach and you draw your #2 battery down with tunes and blenders and all that good stuff then you want to put it to Battery #1 to get it to start up. If you have two good batteries it is best to have it to Both as it will help start the boat faster. If you have two dead batteries you ALWAYS want to put it to One then the other to charge them. To put it to both with two dead batteries is bad!!!! If you have one dead battery it is best to put it on Both after you get her started. This method helps take the stress off the alternator. Make sure you switches stay on as you pass throught from the #1 to the Both to the #2 battery and NEVER pass through the Off possition with the engines running. This creates a spike for the alternator can can cause problems. Good luck.

Jon

Cord

I would take it one step further and never switch the the batteries when the engine is running. There is proably a dead spot between the positions. The spike could be enough to fry the alternator.

Iggy

You can switch between batteries as long as the switch is a "make, before break" type. What that means is the switch makes one connection before breaking the other connection.
On my setup I have a starting battery and a "house" battery. The one for starting is just that, the other is a deep cycle type that I use for everthing else. I charge one at a time while running since most alternators don't have the capacity to charge two at once.

ragtop409

Iggy has got it nailed! I ran a Small Car Audio Shop for a while and that is how whe did all the boats and cars with BIG tunes. Sometimes whe took it one step further and put 2 deep cycles togethe with a battery isolator on the number 2 side of the swich for big long lasting power.

Gary C

I have 2 deep cycle batterys. Actually they are both, Exide deep cycle and starting. So I should use 1 and then the next time out I would use 2? Next question, my amp meter in the boat somtimes drops to 12 then goes back to 14. Does this mean I'm near the end of my battery life? They are the originals in a 98 boat. I have them on trickle now and they don't seem to get past 1 on the charger. I'm thinking it's time for new batterys.

Iggy

I assume you mean voltmeter not ammeter.
They're two different things.
An ammter will show total current draw from all operating circuits.
My voltmeter will at times show 12V with the engine running and then jump up to almost 14V and stay there. I think the voltage regulator is doing funny things or my alternator is going bad. Normal voltage output from alternator should be 13V-13.5V.

If you have two cranking rated batteries I would use one for a day then switch to the other next time.
I have only one cranking battery, the other isn't meant for that. Once the engine is started I'll charge that one first then switch to the other and top it off.
Don't know if your s agoing bad or not. Best way to check is with a load test meter or a hydrometer. Battery chargers will lower the output as battery capacity is reached. My charger will go from 8 amps to 1 as it charges. A trickle charger will only put out about 1 or 2 amps.

Gary C

Doh, I did mean voltmeter Anyway mine does the same thing 12v then jumps to14 and stays there. Maybe I should pull the alternator and have it checked. I was thinking voltage reg. also. Could that cause a starter selenoid to hang up? I fried a starter in the boat 2 weeks ago. Does this stuff ever end? Is the regulater part of the alternator or separate?

Wally

I had 4 batterys and 4 switches in the Scarab. I ran the switches on all while under power to keep the batts charging. When i stopped i turned off all the batts except for the dedicated stereo battery. That way i always has good batterys to start up with.

By the way incase youre all wondering i had it wired up so each engine had its own battery and there was one battery for the stereo system and one for accessories. and i can switch from any one of the four batts to start either engine or give weither engine full juice from all 4 batts!