266ltd

what should i replase the bat. with. it came w junk and dont know wha they came w. stock? i dont know how they are wired either. i dont know if one bat. is cranking both engines or each eng. uses ea. bat. to crank? what came stock is what i would like to put back n.

US1 Fountain

iTrader: (1)

Left motor starts off left battery when the left switch is pointed to the left (POS 1) Same with right side. ...right , right, right (POS 2) (I'm a left/right person)

You can start either motor off of either battery depending on which position the arrow is pointing. Just remember the main wire comes from the motor and goes to the switch on the same side. The arrow points to which battery you want to pull from. Don't leave in the 'Both' position. For simplictiy, I keep everything L and R side orientated, unless I have a dead battery.

The RH side just starts that motor. The LH battery not only starts the LH motor, it also is the 12v power source for everything. This is when the switches are side orientated.

For that reason, I use a starting battery for the RH side, and a dual purpose for the LH battery.

Currently have Interstate as the starting battery, and an AutoZone for the dual purpose. Both of mine have been fine. You'll get opinions on which brand is best.

Dkahnjob

I put Marine Optima's in my boat last summer. So far they have been good. I also run an Optima in my flat bottom and it is 10 years old, and the engine has 12.5:1 compression. So if I get service anything like that for the Fountain I will be happy.
Dave

266ltd

thanx us1. i was debating wether i wantined to replace both w cranking bat. or repl just one with a craning bt. or just spend $ and go with glass mat. so it dosent matter wht the bat. does. since it seems to read to me that both bat. start ea. motor and one runs stereo, will repl. with glass. mat. out of curiosity why do you not leav it on both? i always leave on both?

bob_t

Mercury HP service manual specifically warns not to run twin engine boats with batteries set to "both". They say it can permanently damage the ECM's. Supposedly the two alternators fight each other because neither has its own dedicated ground and you end up with a "floating ground", or something like that. If I remember correctly you can get pretty high voltage fluctuations/spikes when that happens.

US1 Fountain

iTrader: (1)

If you have leave a switch on 'both' and are using alot of juice while floating (stereo) you'll drain both batteries, with no way to start either motor. Also applies if 1 battery is weak or develops a short, it can pull the other one down. I'm also not sure if it's a good idea for both alternators to be working together??? With them being ran independent of each other, you'll always have a way to start both motors, unless both batteries are bad.

266ltd

damn hope i havent done any damage? lean somthing new every day! i will now leave the bat. selector switch on one, or the other bat. sounds stupid how do you dicide witch one to leave on so that both bat. stay charged? or should i just flip flop every time i go out to charge the other bat.

US1 Fountain

iTrader: (1)

Keep the right switch on 1, the left on 2. (facing forward )

I wouldn't worry, tons of people run on 'both'. Don't leave both switches on the same position either, ie: 1 or 2.

266ltd

well now it sounds like you have two bat. switches?? i have one switche, (and have had a 1/5 of rum so the simple seems realy confusing) and it is in the center of the bench i leave it on both all the time witch we have estab. is a mist. so i should switch to one bat. at the time i start ea. motor, and point the switch at the motor im starting? Who and the F*&^ gets so confused about starting there boat? only me. lol. and just change ea. time im out witch motor i start first and then the alt. will charge the bat. that the switch is at dif. ea. time?

266ltd

us 1, if your ever in the shelbyville IL. area i would like to buy you a few drinks, you have helped me tons since i have joined and it is much appriciated!