Alternator rating

[Dan Both]

Thanks for all the great help I have received reading these forums, I wish I had found this web site year ago.<br />I have two questions I can't seem to find the answers to;<br />I have an Evinrude 40 hp CE40TLESR what is the alternator rated amp. output?<br />and<br />how much does the amp. output and voltage vary with RPMs?<br />I'd like to troll with radio and lights on but don't want to kill the battery.<br /><br />Thanks<br />Dan

 

[ob15]

Re: Alternator rating

I believe the output of the cahrging system is 4 amps. The voltage will vary with with rpm. If you have a fully charge battery, I would think you shouldn't have to worry about the battery. The voltage may drop but it would take quite a while (many hours)to kill the battery.

 

[Silvertip]

Re: Alternator rating

I think your alternator is more like 12 amps output maximum. Maximum amperage will probably require 2/3 throttle and voltage may vary 2 to 3 volts over the entire RPM band. The voltage regulator keeps the charge rate at a specific level depending on the charge state of the battery. If its on the low side, the regulator will charge at the full rate. If the battery is fully charged, it charges very little. Voltage will run 13.5 to about 14.5 maybe even 15 at anything over half throttle. Your charging system should handle lights and radio just fine. None of them have a large current draw.

 

[Hunky Dory]

Re: Alternator rating

Assuming a good battery, do this:<br />

• <br />
• Check battery voltage with digital voltmeter.<br />
• Start engine, go to high idle & check voltage again.<br />
• Idle speed, check voltage again. if same or close to high idle we're ready to test otherwise take a lap around the lake to get battery fully charged.<br />
• If idle reaches 13.5v OK else battery is weak and all bets are off<br />
• Turn on accessories. Bonus if same voltage; marginal if greater than 12.5<br />

<br /> This guy is dealing with a high watt demand from a low amp source -- the situation you fear. His methods are interesting...<br /> Some guy's website

 

[ob15]

Re: Alternator rating

My mistake, I didn't se the C at the front of the model and assuming that's a commercial model, it will have more output. Thanks for correcting me Mr. smoke.<br /><br />I think i'm all confused now, looks like a Canadian model. Is there any difference between that motor & mine other than the year. Mine is an 89 J50 (J50TLCEC) & factory manual lists output as 4 amps.