Alternator max voltage?

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Alternator max voltage?

Postby barkleydave » Sat Oct 08, 2016 7:38 am

Was curious what others top off alternator voltages are.

Recently I replaced my 10 year old 2 bank charger with a Pro Mariner 10 amp smart charger. It is automatic and will put up to 20 Amps in one bank if required. (example house batteries lower than start bank) Anyway it will take a battery up to maximum absorb. at 14.5 volts then the charger goes into automatic maint. mode. The charger will also charge AGM banks. This means it provides little or no amperage to the battery until the voltage drops to a pre-determined level. Also once a month it will condition the batteries. The rest period is great since it does not boil your batteries by remaining in constant float mode.

Here is my question: My alternatosr (single wire 62 amp ARCO) only seems to max at 13.8 volts. That means while running they will not max out the batteries. The alternators are not smart they just push until the internal regulator backs them down.

I am no wondering if my Alternators are sending me a signal it is time to replace them? I have only tested my STB alternator which charges the STB bank which is also used as my house bank. My bank is 6 years and I am planning on replacement next spring.

Thanks for any thoughts and experiences

safe harbors,
1987 Marinette 29 FB Sedan
Retired Boat Accident UL and USCG trained investigator
Retired USCG Captain

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Re: Alternator max voltage?

Postby Busia » Sat Oct 08, 2016 12:22 pm

13.8 volts is fine as long as it shuts off once the batteries are charged. (that your regulator is working) --Ed
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW