Battery overcharging?

[gumball]

for some reason my battery gauge is right around 18 volts after the engine is running, is that ok for the battery? is the voltage regulator bad? where is it? 1973 merc inline 6 150 hp, pics help wonders if possible, anything else i should check?

 

[briannh1234]

Re: Battery overcharging?

No voltage regulator on that motor - you would have to add one yourself. Normally the battery provides the regulation. Your battery may be getting a little old but I would check the connections at the battery first.

 

[emckelvy]

Re: Battery overcharging?

Install a newer rectifier with integrated voltage regulator as noted above. The most recent replacement combo's are small enough to mount on the front cowl support. Look at the reg/rect assy's that came on the Big Threes (70-90HP) and Fours (i.e. 115HP etc), as these would probably be a good match for your system. The V6's also used (2) of the same reg/rect assy.<br /><br />Another Zero-Cost alternate is to provide a constant load on the system which will keep the voltage down to a reasonable level; just keep the boat's running lites on all the time.<br /><br />18V is kinda high, I'd verify the accuracy of your voltmeter by checking the battery voltage with an accurate digital or analog VOM.<br /><br />HTH......ed

 

[sprinkler]

Re: Battery overcharging?

You don't have a sealed battery, do you (you shouldn't). Check the water level in the battery. My voltmeter was registering high. I checked the battery and the plates were exposed. I added water and it went back down to 16V at WOT.

 

[gumball]

Re: Battery overcharging?

ill check it with a voltmeter, but its a brand new battery, and brand new gauge. water level is fine. thanks for all the help. not a sealed battery either.