Mercruiser 170 with Stator, one or two batteries on?

Brock.Ward

Petty Officer 2nd Class
Joined
Jul 1, 2010
Messages
148
Got the infamous 170 3.7l engine with stator. All stil works great, pretty sure was all replaced when engine was installed 2 years ago. The boat is a SportCraft 205 offshore and this engine runs flawless on Lake Michigan Salmon fishing. Only question I have is I haev dual batteries with a switch. One is a starter one is a deep cycle, since I got this boat I have always just turned switch to all or both batteries on all the time, I troll all day with it with electric downriggers, radar, sonar, gps etc. Is that ok? I know the Voltage regulators are known for overheating so my questions is will running two batteries since alternator is always charging both harder on the voltage regulator? I would rather have both batteries charged all the time in case it does go out so I can at least call out or get back in with the charge left if I see the voltage go under 14 or 13.7... any help or feedback is apprecaited. I will be getting the conversion kit at some point this year but its all testing out great so I dont see a reason to replace it right this second.
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,023
Wouldn't think it would have a noticeable effect. Why bother with the conversion if it's working fine? My original setup went 27 years before failing...
 

Brock.Ward

Petty Officer 2nd Class
Joined
Jul 1, 2010
Messages
148
I'm not going to replace it, I agree, just throwing that out there. But ok i'll always leave it on two, didnt know if that overworked the stator and then would cause the voltage regulator to overheat a bit...figured id ask to be safe...other question. I have an 18hp evinrude. beleive it or not i have seen people throw kickers on them tiki boards on the back, mine is supported very well, you think it could hold an 18hp kicker? Mount it right on the wood?
 
Joined
Mar 27, 2010
Messages
3,008
I wouldn't touch the factory charging until you have an issue. The only thing to watch for is shutting the switch to the off position while running, that's bad. Other than that, any position you'd like. I run two batts and the same switch also.

I've switched to a belt driven alt. though. I wouldn't worry about the effect of charging one or two batts. using the stator.
 
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mr 88

Commander
Joined
Nov 3, 2010
Messages
2,115
If you have one battery that is weaker than the other it will draw the stronger one down to it's level. So in that case I would only leave the switch on one or two,that way there isolated.If you have a weak battery and the stator stops charging you may have end up with a starting issue as you now have two weak batteries. I have one battery hooked up for starting and one for accesories,once started I switch it to the acc. battery. So I have a fresh starting battery at all times and don't worry if the acc.battery goes dead. Also I carry a 100.00 mini jumper pak and never worry about the batteries anymore.
 
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