Bizarre Electrical???

I have a 2014 Sundancer 280.

Spent the weekend at the marina and before bed noticed that the cabin lights seemed a tad bit dimmer than usual - but not enough to do anything. The floor lights were flickering albeit very subtle. The TV had a hard time keeping a channel locked in to a signal, assumed not enough power to the antenna.

Woke up to an alarm on the generator that said low battery. I put everything together and assumed that I am not running on full power.

I'm running on shore power, not generator as the gen isn't even working anyway and is powered down.

The battery was on battery 1. I turned the battery switch to off, which shut the generator alarm off. Switched to battery 2 and noticed that the lights were brighter and the floor lights stopped flickering. Went back to battery 1 and everything seemed fine.

So now I have many questions.

What would cause the lower power?

Even though I was hooked up to shore power, am I still running on battery or some form of it? I had did have the battery charger on as I always do when at the dock on shore power.

Why would the generator (Kohler) set off an alarm when it isn't even on (or working).

Why is there no way to shut the alarm off on the gen, without turning the battery switch to off?

Is it possible that all I need is a new battery? The current ones are about 2 years old anyway.

Next morning boat started and ran fine and everything worked.

I am a bit perplexed and know very little about electrical so would love some feedback and thoughts on this.

Very appreciative to be able to tap into the knowledge of this great community.

Steve

I would check the batteries with a volt meter directly.
If all you did was turn the battery 1-both-2 switch between batteries at it resolved the issue.
The battery switch may be corroded internally, you wiped the contacts and it got a better connection.

If batteries check ok,
put a slight load on it say a blower,
test the voltage again it should be the same at the battery and after the switch, if any drop after the switch its starting to fail.

Make sure your battery charger is turned on.

A shorted battery can cause innumerable, unexplainable goings on. Check the batteries fluid for proper level and acid content. Make sure the batteries are independently giving the appropriate voltage. Might have just one cell that's causing the issues.

bahamabreisus said:

Make sure your battery charger is turned on.

Click to expand...

This above or see if your charger just died.

I mistakenly turned off the AC Converter and ran my house batteries dead at the dock. I was like "what now" until I figured it out.

Hope it is as simple as this.

First how old are your batteries? I agree it may just have been dirty contacts in the battery switch but it seems that everything you had running is on 12 volts? That's why you were seeing the flickering as your voltage dropped. Anyway start with examining your batteries age and condition then move on to loose or corroded contacts and grounds.

Please read the Original Post completely first before throwing all kinds of possibilities around.
The OP already stated
Status:
Batteries 2 years old
On Shore power, battery charger on.
Generator not running, (but the control panel will be 12v powered as long as the battery switch is on)

Symptoms:
cabin lights dim,
lower lights slight flicker (possible LED?),
TV signal strength (possible due to amplified TV antenna?)
Low volt alarm on generator panel

Cure:
Cycled battery switch and everything returned to normal operation
(possible corrosion internal or external, possible lose connections on switch)
The only assumption I am making is that this is the only thing the OP did and it resolved the issue.

Diagnostics:
Apply a load, (a larger load will cause a larger voltage drop across a poor connection, fan, pump or lots of lights)
check battery voltage at battery terminals
check voltage after the switch (wiggle it a little, wiggle the cables while measuring)
There should be no voltage drop across the switch (same voltage)

You can also use the multi-meter in resistance (ohm meter) mode across any suspected poor connection. This will be resistance which should be zero anything over a few Milli-ohms (0.001 ohms) is suspect.
As a comparison common 16AWG marine wire has just 1 ohms resistance per 250 feet of wire.
So even just 0.25 ohm resistance in a switch would be like adding 62 feet of wire to the circuit.

Dead battery or dead cell not going to suddenly revive just by cycling the battery switch.