2002 Mercury 115 ELPTO 2 Stroke electrical output

[LakeMichiganBoater]

I just purchased a 2002 Princecraft Ventura 221 with a 2002 Mercury 115 ELPTO 2 Stroke motor with serial OT54xxxx.

The previous owner installed a large stereo system and a second battery, but did not connect the second battery to motor/first battery. I plan to use a battery isolater to connect the two, but am worried about the electrical output of the motor. I'm used to dealing with alternators on I/Os but I'm assuming this is just a stator/coil and don't want to burn it out.

Does anyone know the amp/watt output of the motor and what a safe draw would be while running?

If it's too much I could just keep the batteries isolated.

Thank you.

 

[cyclops222]

Paralleling batteries SOUNDS GOOD> BUUTT
You are putting larger and LONGER high currents that the motor charging system is groaning under. You can easily cook the recharge coil in the O B.
Never put a rundown music battery across your FULLY charge up cranking / starting battery. The musick battery will suck the start battery down to the same level.

SURPRISE Why is my go home starting battery sound like it may not spin fast enough ? You choice if you or someone else using your boat is unlucky.

 

[LakeMichiganBoater]

Paralleling batteries SOUNDS GOOD> BUUTT
You are putting larger and LONGER high currents that the motor charging system is groaning under. You can easily cook the recharge coil in the O B.
Never put a rundown music battery across your FULLY charge up cranking / starting battery. The musick battery will suck the start battery down to the same level.

SURPRISE Why is my go home starting battery sound like it may not spin fast enough ? You choice if you or someone else using your boat is unlucky.

Agreed.... what are you thoughts on low amperage b2b charger instead of isolater?

I typically use an isolater that disconnects under 12.7 pretty quickly, and reconnects slowly once above 13ish... so they should not immediately drain the starter battery until the stator is going strong, however my concern was how powerful these stators are and if it the drain would put to much strain on it.

 

[boscoe99]

Many folks have their Mercury motor starting batteries connected to a house battery via a VSR/ACR/Combiner/Etc with no ill effects so that the alternator charges each battery according to its own needs.

Some Mercury models use two voltage regulators where one charges the start battery and the other charges a house battery. Or the two can be connected together such that both regulators charge the start battery. You might want to see if your motor has that capability.

If it makes you feel more comfortable then certainly the house battery can gets its charge current from the alternator via a DC - DC charger. It will just take longer to charge the house battery if you restrict the flow of current to the battery.

 

[cyclops222]

What does a 2002 Mercury 115 hp 2 stroke provide as a constant recharge current.
Please do not post the useless findings of A I. It has no USEFUL BRAIN.
I found the factory specifications. Either 4 amps or 6 amps at 6000 rpms. Much less at idle speeds.

 

[LakeMichiganBoater]

What does a 2002 Mercury 115 hp 2 stroke provide as a constant recharge current.
Please do not post the useless findings of A I. It has no USEFUL BRAIN.
I found the factory specifications. Either 4 amps or 6 amps at 6000 rpms. Much less at idle speeds.

Oh wow, that's pretty low. I found 16-20amps on newer ones, but nothing for this older 2 stroke. If it really is only 4-6amps then I need to keep that house battery separate and shore charge it.

 

[boscoe99]

Low? That is pathetic.

 

[boscoe99]

Why the missing serial number digits?

 

[boscoe99]

What does a 2002 Mercury 115 hp 2 stroke provide as a constant recharge current.
Please do not post the useless findings of A I. It has no USEFUL BRAIN.
I found the factory specifications. Either 4 amps or 6 amps at 6000 rpms. Much less at idle speeds.

A Mercury two stroke with an RPM of 6000?

 

[flyingscott]

What does a 2002 Mercury 115 hp 2 stroke provide as a constant recharge current.
Please do not post the useless findings of A I. It has no USEFUL BRAIN.
I found the factory specifications. Either 4 amps or 6 amps at 6000 rpms. Much less at idle speeds.

Are you positive that motor spins 6000 RPM

 

[flyingscott]

Oh wow, that's pretty low. I found 16-20amps on newer ones, but nothing for this older 2 stroke. If it really is only 4-6amps then I need to keep that house battery separate and shore charge it.

Is this the 4 cylinder motor? If it is you have a 16 amp charging system. If it is the 4 cylinder you never spin them past 5250 rpm. If it is the v6 or 3 cylinder opti motor disregard.

 

[boscoe99]

Folks don't like to tell folks what motor they have.

 

[Texasmark]

If the stator is red its 16 ampere rated and that is at max RPM. That is the max rating and I don't remember the output voltage when it supplies that current. Max voltage is regulated at 14.5V max under certain amperage conditions....like topping off a near fully charged battery with trickle current flowing.

These alternators are designed to keep a fully charged battery fully charged while the boat is in use and were not designed to keep BOOM BOXES blasting (opinion but probably correct).

 

[cyclops222]

Perfect Mark. DIY can be so reckless with good equipment.

 

[flyingscott]

16 amp is plenty to run some accessories. All the 4 cylinders are 16 amp.

 

[LakeMichiganBoater]

Why the missing serial number digits?

Haha, all i could remember off the top of my head.

 

[LakeMichiganBoater]

It is a 4 cylinder. 16amps at high RPM still makes me want to keep the batteries separate and shore charge the one I use for audio.

Getting a trickle b2b charger seems pointless at this point. Just wait for shore power. Boat will not be staying in the water, always trailered.

 

[boscoe99]

I would guess that your motor has pull start capability. If so, no harm no foul if the start battery goes dead.

Having said that, I see no problem in having two batteries. One for start and one for the house. With a VSR/ACR/Combiner/Isolator/Etc. between the two.

The alternator on your model does not produce enough current to harm anything.

 

[cyclops222]

" We did not know that the 2 batteries could be connected together. When the Isolator failed. "