Low System Voltage Warning - What's my next move?

[BBBri]

I'm getting an occasional "low system voltage" warning on my glass garmins on my 23 SC. It usually comes on when I am starting my first acceleration, and then the engine suddenly drops to idle (along with my heart dropping when that happens). I usually wait about 10 seconds and then slowly accelerate again and then there are no problems - except on following days when I start. First question, can I hurt the engine by trying to accelerate without doing a repair - I don't know what to fix. Secondly, obviously, what the heck is going on? My boat only has 250 hours and is 4 years old - do I need new batteries? Thanks for any help.

[Tgoertz]

I have a 2021 25SC with dual battery and had a similar thing happen to me. Low voltage alarm went off while anchored (fishing). Started engine to have alternator recharge batteries. Noticed, the voltage was not increasing and decided to head in. Any time we got over 3000 RPM the engines slowed back down to 1000 RPM. Fortunately I was able to limp to shore and beach the boat until sea tow could give us a tow in.
For me it was a dead alternator (not under warranty).

About a month after replacing the alternator, had a similar problem. This time, engine wouldn't start at all and was able to call a friend who came with jumper cables. After just replacing the alternator, both batteries were dead. Not sure if one caused the other.

Something I learned, the batteries that came with the boat are category 24 starting batteries. Mercury recommends category 31 dual-purpose AGM batteries which are double the price.

I would get both your battery and alternator checked out.

[Krob1114]

We had the radio turn off with low voltage warning. We sometimes drifted for hours in the wind.
Replaced batteries that we have used almost 7 seasons, and no problems.