Voltage - Battery or Alternator Issue?
 

Hey everyone,

My last time on the boat, it had been sitting for a week. After starting like normal, I noticed the voltage gauge showed 10.5 volts. I revved it up a little, and it went up to the normal ~14 volts. But after letting it come back to idle it showed 10.5 again. I then took it out for a 5 minute run to see if that would cure it. During that time, it showed 14 again. Went to the cove to hang out, looked at it about an hour later, and it was back at 10.5. My whole drive back to the slip (at idle, as it was dark) it stayed at 10.5.

My question is this... Do I have an issue with the battery/batteries, or the alternator? The batteries are only 1.5 years old, and I've never had an issue before. I installed the new amp/stereo and have had numerous nights out lately that could have just drained them and never let them fully charge again. I'm hoping that's all it is - I'll be skiing/tubing later today, which should charge them back up. So this question may just be wasting everyone's time. I'll provide an update tomorrow, but was hoping to get an idea of the problem before going out this afternoon.

Oh yeah, here's a picture of my last time out (trying to charge the batteries on that 5 minute run ;) had nothing to do with a speed fix :yes_grin:)

Thanks!

What type of batteries do you have installed in Ryan? If they are just starting batteries rather than deep cycles then discharging them below 9 - 10 volts can damage the battery beyond repair and they usually will not hold a charge again. Deep cycles are designed for repeated charge and discharge but starting batteries are designed to remain around 12 - 13 volts.

If it were me, i would go pickup a brand new battery and see if that solves the problem. Double check on the return policy though in case the problem persists even with the new batteries. Then you'll know its the alternator.

If a new battery still doesn't solve the problem then you can pull the alternator and take it to an auto parts store that does testing. They can hook it up to a machine and put an artificial load on it and see if the alternator is still good.

Let us know what you find out!

They're both deep cycle. I'm heading out right now and will report back tomorrow (if I'm able to move - I'm going to slalom for the first time in about 12 years).

Thanks for the help.

I slalomed for the the first time in several years. It wasn't too bad the next day, although I could not/did not go very far before letting go.
Good luck with that.

Also doublecheck all your connections, sometimes all the wires don't get hooked back up when installing things. I'm guilty of forgetting a wire when connecting everything, but usually catch it 10 minutes later. duh!

All is good! I drove around the lake, then did my skiing, and it's now back to normal. I must have been out too many nights and not giving them a chance to charge back up. Even at the end of the night, without the engine running, it indicated just under 12 volts.

BTW - I got up on the first try!!! Made a few cuts, fell, got up again on the first try, made one cut and bit it hard. After that, I was done! It was a LOT harder than I remembered - I guess 12 years and 20+ pounds will add a little more difficulty!

Ryan, mine does that too. At low idle speeds, the voltmeter will show low even though at times I had topped off my engine battery with a trickle charger overnight. I don't lose much sleep over it! As long as your running voltage stays up in the green.

Doug, glad to hear yours runs likewise. Mine acts the same, as long as it jumped up to normal at higher speeds, I did not worry too much about it.

Yeah, mine always showed just under 12 at idle, then about 14 while cruising. What worried me was when it showed 10.5 at idle. Looking back on it, I realize there were probably 3 nights out on the boat, stereo rockin', and idle speed back to the slip that didn't allow them to charge back up. I'm confident they are good now. Thanks for the responses!

Mine is the same way. Occasionally when I feel the urge, I'll start the boat up and run the throttle up in neutral, until the lights brighten up and the voltage goes back up to around normal. i'll run it for about 3 minutes or so, and then turn it back off. I see lots of people doing this for concerts and raft-ups and such. I'm planning on putting a dual battery monitor onboard just for that peace of mind, as I plan to actually overnight on mine next year quite a bit, somehow I managed to indirectly convince the GF, and she WANTS to stay onboard! :wink_thumbup: