Battery Not Maintaining Charge

[mcpo]

I have an 89, 70HP Evinrude. I take the boat out with a full 100% charge and when I come back in, it is at 70% usually. Does this mean that something on the motor is not maintaining the charge like it should?<br />Thanks,<br />Cal

 

[ndemge]

Re: Battery Not Maintaining Charge

Do not know the charging system of your motor..but...<br /><br /><br />Check voltage of battery before starting (after it has set) <br /><br />Start the engine, Voltage should come up to show alternator is charging.<br /><br />If the voltage does not go up, your not charging.<br />If it DOES go up to around 13 volts, it means you are charging, and probably a bad battery.<br /><br />My $.02

 

[mcpo]

Re: Battery Not Maintaining Charge

It is an outboard 70 HP Evinrude, 1989. It doesn't have an alternator, and the battery is brand new. I thought it might be the rectifier. Just not sure.<br />Thanks for the reply.<br />Cal

 

[ndemge]

Re: Battery Not Maintaining Charge

If it doesn't have an alternator, then it can't charge the battery.

 

[phatmanmike]

Re: Battery Not Maintaining Charge

why doesnt it have an alternator.....technically none of these outboard do, well other than the new verado's. they have stators wich produce AC voltage which feeds down to the rectifier, which inverts the AC voltage to DC voltage(12 volts). if youve ever hooked up your battery backwards, or touched a hot wire to the ground accidently, anything that caused big sparks, could have fried your rectifier.<br /><br />if your rectifier is gone, you need another to charge your battery.<br /><br />radio shack sells a full wave bridge 25 amp rectifier for $3.79... it is FAR superior , faster batt charging, than the origonal, and its cheep, i bought 2. chris1956 told me about it. hooks up in 5 mins. he has been using his for 20 years. check it out

 

[mcpo]

Re: Battery Not Maintaining Charge

ok, thanks.

 

[rickdb1boat]

Re: Battery Not Maintaining Charge

Or you can buy a new one from here for $38.00. I just did...<br /><br /> web page<br /><br />Look like this??<br /><br />

 

[kd6nem]

Re: Battery Not Maintaining Charge

PMMike, most rigs which use a rectifier do so (as you point out) because they output AC, not DC. Isn't that what makes them an alternator? They don't have to look like one to be one. Alternators big advantage is that they work much better at lower RPM's than generators do.<br /><br />I don't want to assume too much one way or the other here- so take this with a big grain of salt- Just make sure you are not bypassing a voltage regulator which can sometimes look like a rectifier without understanding the implications, and make sure your new rectifier can handle all the current YOUR motor's alternator is putting out. Otherwise you're liable to see smoke coming from under the hood of your outboard. If the new rectifier needs a good heat sink make sure it has one. Otherwise, sounds like a clever idea. I guess I don't see why you should have much more current delivered just by changing a rectifier.<br /><br />By the way, I really like you Salmon picture!

 

[mcpo]

Re: Battery Not Maintaining Charge

great picture....same engine i have. I think I'm going to change the rectifier. Seems to me that I did that on my last motor because it wasn't maintaining a charge on the battery and that cured the problem. I had forgotten about that. Anyway....I appreciate all the input.<br />Cal

 

[kd6nem]

Re: Battery Not Maintaining Charge

Might be a good idea to check how much AC is getting past the rectifier. Much AC and you'll be doing the battery no favors at all. Set your voltmeter to AC and measure at the battery with the motor running. A very small amount is no cause for concern. A volt or two and you definitely need a new rectifier! You can change it just for fun, but if the charging system is putting out and there is very little AC component then there is no reason to change the rectifier. Identifying the problem first is usually cheaper than changing parts out randomly to fix it. If there is no AC going INTO the rectifier you can change it 100 times and still not fix the problem. Sometimes it is simply a dead stator. Or a dead battery. Look closer for mor symptoms first.