CaptBobO
Member
- Aug 31, 2020
- 49
- Boat Info
- 2000 410 Sundancer
- Engines
- 8.1L Mercruiser Horizon
Here is a question for you electrical pros out there.
I have 2007 Mercruiser 8.1S Horizon engines in my 410.
Last weekend my voltage dropped on my port motor to 12.3 and the engine died.
I couldn't get it started using the emergency switch. I started up the generator and let it charge my batteries. Then, the voltage dropped on starboard and that died as well.
Thankfully after about 30 min the batteries charged up just enough to start the SB motor and start heading back in. the alternator was able to send a charge back to the SB bank.
Then, the Port motor finally started up due to my generator helping out.
My question is, what is the world could have drained my battery that quick?
Side notes: my stereo is on its own dedicated bank of batteries, so that was not part of the drain. Also, my batteries are only 8 months old. I replaced all batteries in the boat. My port motor also has a brand new alternator.
Does the alternator send the charge directly to the batteries, or does it go through the built in battery charger first? Reason I'm asking, is could an old/defective battery charger be the cause? mine is original to the boat.
Once I finally got home, I left it plugged in to shore power, and the next day, it started right up!
14.3 volts across the board. unplugged it from shore power, and still held 14.3 at idle.
What are your thoughts? what could have drained my battery that fast after a long run and then an idle cruise for about 20 min?
Thank you!
I have 2007 Mercruiser 8.1S Horizon engines in my 410.
Last weekend my voltage dropped on my port motor to 12.3 and the engine died.
I couldn't get it started using the emergency switch. I started up the generator and let it charge my batteries. Then, the voltage dropped on starboard and that died as well.
Thankfully after about 30 min the batteries charged up just enough to start the SB motor and start heading back in. the alternator was able to send a charge back to the SB bank.
Then, the Port motor finally started up due to my generator helping out.
My question is, what is the world could have drained my battery that quick?
Side notes: my stereo is on its own dedicated bank of batteries, so that was not part of the drain. Also, my batteries are only 8 months old. I replaced all batteries in the boat. My port motor also has a brand new alternator.
Does the alternator send the charge directly to the batteries, or does it go through the built in battery charger first? Reason I'm asking, is could an old/defective battery charger be the cause? mine is original to the boat.
Once I finally got home, I left it plugged in to shore power, and the next day, it started right up!
14.3 volts across the board. unplugged it from shore power, and still held 14.3 at idle.
What are your thoughts? what could have drained my battery that fast after a long run and then an idle cruise for about 20 min?
Thank you!