Alternator Output - What is Normal?
YYZRC
Member Posts: 5,111 ✭✭✭✭✭
When I'm at idle, my VV shows 14.x volts both port and starboard.
When on plane, my VV was showing around 12.x volts starboard and 13.x volts port.
I swapped the alternators and now show 13.x volts on starboard and 12.x volts on port.
Weak alternator? What's normal?
When on plane, my VV was showing around 12.x volts starboard and 13.x volts port.
I swapped the alternators and now show 13.x volts on starboard and 12.x volts on port.
Weak alternator? What's normal?
2008 350 EC on Georgian Bay
Comments
Dream 'Inn III -- 2008 400 Express
https://a.co/d/fYwfccI
the alternator produces what the alternator produces and if it's regulated AT the alternator it can be hard to determine... if it's at the computer and beyond, you can check the alternator at the post.
that reading is more about electrical usage and battery condition than alternator output, anyway. a healthy battery is 12.6vdc at rest.. it takes 13.5vdc or so to actually charge a battery and 14.5vdc to really charge a battery full blast- over 15 isn't uncommon but it usually demonstrates a regulator about to give up the ghost...
while underway your charge shouldn't fluctuate, but it could be different from bank to bank as the alternator may be wired to charge separate systems which may be at different states of charge due to usage.
flooded lead acid can't take the charge lithium or mats can. likewise, a system set to charge a flooded lead acid may not be charging another type of battery- especially lithium- as thoroughly as it should be... lithium likes higher voltage and volume (amps) than flooded can handle without swelling... gotta keep your systems matched.
so long as your readings don't fall below 12.6vdc underway don't make any stress for yourself... stress if it's above 14.5vdc for prolonged periods (showing the alternators are producing but your batteries are weak) or below 12.5vdc (demonstrating your alternator isn't taking over for the batteries while underway)...
before computers and LED's complicated these things, the easiest way to tell if a battery or an alternator was weak was to use a 12vdc halogen bulb at the battery itself- when the engine revved if the bulb brightened- the alternator was good but the battery weak... if it dimmed while the engine was underway the batteries were being drained by the engine and teh alternator/generator couldn't keep up. i guess this could still be done, but your computer may think about that extra draw and form some idea about setting a code none of us would be able to decipher.
Did you install the vessel view link or gateway ? I have the gateway but can only display on my simrad instrument tab and I don't get the fault data. Wondering if there is a workaround to get the vessel view screens like you have without the vessel view link?
2015 Scarab 165G
Laser Sailboat
2002 Seadoo Explorer
2023 Seadoo Spark Trixx x 2