High voltage when cruising

[arguzin]

I have a Mercury 60 outboard on my 16' Sleekcraft. I noticed that the voltage meter on the dash marked the correct 12V when starting the engine, but when throttle is increased the meter gradually reads up to 15V. Besides powering the engine the 12V battery has a single power line (fused) which feeds a 7amp stereo and the VHF. When anchored (with engine switched off), the voltage reads 12V and the radios work fine. But when I tried to switch on the VHF while cruising it showed a "Hi-Voltage" warning beep and I turned it off as a precaution. Could it be that the power line feeding the radios is interfering with the voltage distribution, or could it be an engine problem (eg. alternator)??

 

[Don S]

Re: High voltage when cruising

You have a charging problem, what is the serial number of your motor. Or even the year, 2 or 4 stroke, carbed, EFI. etc.

 

[arguzin]

Re: High voltage when cruising

You have a charging problem, what is the serial number of your motor. Or even the year, 2 or 4 stroke, carbed, EFI. etc.

Thanks for the interest. It's a Mercury 60 2-stroke. Engine No. 10605289435777. I've checked with a mechanic who told me that the model is equipped with a rectifier only (NOT a rectifier regulator). Hence, when throttle is increased, the voltage can go up to 15V from 12V. He assured me that apart from the battery, the motor performance won't be affected. The ideal solution would be to install a rectifier regulator.

 

[Silvertip]

Re: High voltage when cruising

15 volts is the high limit for most electronic gadgets so if they have a high voltage alarm it will likely trigger it. Unregulated charging systems are not a problem as the battery does that job on low output charging systems. Newer motors have much higher output charging systems so a voltage regulator was included. Battery life may be affected if you make very long runs at WOT but if you keep the water level topped off you have what you have and battery life will be what it turns out to be. You might investigate the aftermarket for an external regulator you can add to your motor.

 

[arguzin]

Re: High voltage when cruising

15 volts is the high limit for most electronic gadgets so if they have a high voltage alarm it will likely trigger it. Unregulated charging systems are not a problem as the battery does that job on low output charging systems. Newer motors have much higher output charging systems so a voltage regulator was included. Battery life may be affected if you make very long runs at WOT but if you keep the water level topped off you have what you have and battery life will be what it turns out to be. You might investigate the aftermarket for an external regulator you can add to your motor.

Thanks for the info. Much appreciated.

 

[Yesterday]

Re: High voltage when cruising

I do away with all those factory rectifiers and replace them with a rectifier/regulator combo. They're only about $40.00 locally.

 

[sutor623]

Re: High voltage when cruising

I ordered from amazon, a $30 12v regulator. (works from 8v-40v input, up to 6 amps) The regulator is made by Tobsun. I have it just before my high dollar electronics. Now my fishfinder doesnt say low voltage when I start the motor, and doesnt ever spike over 12-13v on open throttle. Most of my outboard motors have spiked up to 15 or 16v during WOT runs. Just an FYI.

 

[sutor623]

Re: High voltage when cruising

I do away with all those factory rectifiers and replace them with a rectifier/regulator combo. They're only about $40.00 locally.

Hey bud you got a link to something like this? Id like to consider something like this.....

 

[mercurymang]

Re: High voltage when cruising

Here's the one i bought. Works good for me.

Amazon.com: Sports Parts Universal Regulator/Rectifier 01-154-16: Automotive

 

[sutor623]

Re: High voltage when cruising

Here's the one i bought. Works good for me.

Amazon.com: Sports Parts Universal Regulator/Rectifier 01-154-16: Automotive

Cool man, thanks.

 

[Yesterday]

Re: High voltage when cruising

The ones I've been using "look" literally identical to the one mercurymang posted.

I find it amusing how merc (& no doubt vatious other manfacturers) can charge in excess of $100.00 for a rectifier when this is what a "sealed unit" rectifier really is worth:
Amazon.com: 400V 25A Bridge Rectifier: Electronics

And yes, a rectifier is a rectifier is a rectifier as long as it can handle the current. 25A is loads for almost any O/B application.

 

[mercurymang]

Re: High voltage when cruising

The ones I've been using "look" literally identical to the one mercurymang posted.

I find it amusing how merc (& no doubt vatious other manfacturers) can charge in excess of $100.00 for a rectifier when this is what a "sealed unit" rectifier really is worth:
Amazon.com: 400V 25A Bridge Rectifier: Electronics

And yes, a rectifier is a rectifier is a rectifier as long as it can handle the current. 25A is loads for almost any O/B application.

Totally agree. From what I can tell, when you buy one from mecury, it has the bolt holes to match your motor, otherwise, it's the same thing.

 

[Yesterday]

Re: High voltage when cruising

Totally agree. From what I can tell, when you buy one from mecury, it has the bolt holes to match your motor, otherwise, it's the same thing.

And the Merc one uses it's chassis for a ground as opposed to a pin. Simple to put a wire from the DC out ground pin to the motor's ground.

 

[ondarvr]

Re: High voltage when cruising

I ordered from amazon, a $30 12v regulator. (works from 8v-40v input, up to 6 amps) The regulator is made by Tobsun. I have it just before my high dollar electronics. Now my fishfinder doesnt say low voltage when I start the motor, and doesnt ever spike over 12-13v on open throttle. Most of my outboard motors have spiked up to 15 or 16v during WOT runs. Just an FYI.

If you're not reaching at least 14.2 volts or so you're not charging correctly. And the low end voltage would not be affected, it would be the same with or without the regulator.

 

[ondarvr]

Re: High voltage when cruising

You can get same thing at Radio Shack for the same price. I use them on all my motors.