alternator questions

[g00se]

My batteries have been going dead for the last year. I just give them a boost after every trip and I am fine. They do recharge a bit after a few houirss running at high rpms, but not too much. Do I need to trash the 1-2-all-none system and get on the switch system or do I need a whole new alternator? Do the aftermarket alternators charge at a lower rpm? Any help would be much appreciated, thanks.
Sean

[kepdawg]

Batteries do get old.
A few things:
What is the amp load with normal running electronics on?
What does your alternator/generator rated at for normal cruise and at idle?
Are the terminals and batteries clean, full to the lower lip with distilled water? Are they lead acid batteries?
Have you tested for bad cells with a hydrometer?
When your at idle what is the battery voltage? Should be around 12.2-13.0 with no electronics on.
At cruise what is the voltage? It should be 13-14.5 MAX
(test only one battery at a time with a volt ohm meter @ the battery terminals)....
When testing don't run the engine with the battery switch in the off position --- BTW.
The last thing I'd do if everything tests OK, then you might just have a wire problem or a ground problem. That would require testing at the alternator.

Seems like a lot of work, but this is just standard trouble shooting
not advanced ...

[Miss Yoly]

g00se,

How many amps does your alternator put out? Let me give you some examples of power draw. Rememer that it takes amperage to power the following. Here's what I'm putting on my new boat.

Device Amp Draw
Furuno FCV600L Fishfinder 1-0.5A
Furuno 1650D/NT Chartplotter 1.2-0.6A
RayMarine ST-5000+ Autopilot 1.5-0.5A
Furuno 1722 Radar 3.8-1.9A
500 gph bilge pump 1.9A when used
Navagation lights 1.0A when used
700 gph baitpump 3.5A
Decklight 50 Watt 4A
I-Com 502 VHF Marine Radio receive 1.2A
transmit 6A

You can see how easy it adds up without thinking much about it. The old outboards normally had low amp alternators so in some case you were in a deficit even while running.

Might want to take an inventory of electrical requirements to see where you stand.

Hope this helps.

[Mot's Sr.]

Call KMAN