Electric help please

[SgtAlf]

OK, got on the boat today and fired her up. Turned on the GPS and got a low voltage alarm. Looking around I found the breaker for the charger turned off. The boat was plugged into shore power. I think I saw my volts at 8.8v. I had zero lights on the breaker panel. I plugged back into shore power, turned on the charger breaker, turned on the parallel to reset the charger and everything came back on. I left her to charge all day. I just checked again, same thing, no lights on the breaker panel with the engine running and off shore power. Have I killed the house batteries, or perhaps the alternator on the engine went bad? The charger seems to work on shore power...

 

[Hamster]

If your house batteries were that low, you probably have to get new batteries. I’d highly recommend a battery monitor, too, as that would tell you whether your engine alternator is putting out amps while running. The other thing to check before you replace the house is that your ACRs are working. When you plug into shore power, they should show the ACR opening (green, if my memory serves me well).

 

[SgtAlf]

Hamster, what’s an ACR?

 

[HookedUp]

Probably as good an explanation as any: https://www.bluesea.com/support/articles/1366/Automatic_Charging_Relay_[ACR]_Explained

 

[GaylesFaerie]

With regard to "...they should show the ACR opening...". I believe you mean "... show the ACR closing...". An open circuit has no electricity flow. When the ACR opens the circuit between the batteries they are disconnected and not charging together. When the ACR closes, the circuit between the batteries is closed (complete) and the batteries will charge together. When the green light is ON, then the circuit is closed and the batteries are charging together. HTH, GF

 

[SgtAlf]

After 24 hrs. on charge I'm showing 13.5v off shore power and engine off. What I don't have are any lights on the electric panel when off shore, engine off, or engine on. Should there be?
So, it seems my charger, and alternator both work. Batteries are back to 13.5v at least. They may need to be replaced, but still have some life in them.
With all that's happened in the last 24 hours, I, for the life of me, cannot recall if I ever had any lights on the electric panel when off shore power.

 

[GaylesFaerie]

What "electric panel" are you referring to? The one with all the breaker switches? I have two sets of lights on my panel: one lights up only when an individual breaker is closed to show power is flowing for that circuit - in other words each breaker has a dedicated light to indicate it is active. In addition, when my navigation lights are ON, all switches are backlit with a light for visibility in the dark. HTH, GF

 

[Martin610]

Hey Sarge,

I don't think the battery switch for the engine will light up any lights on the panel. It doesn't on my boat.

Regarding your batteries, I would put a multi-meter on each battery individually, to ensure they are all good. Look for loose connection, corrosion, etc. You can also put a load tester on each battery. Just because they show 13.5 doesn't mean they can really hold a charge. Load testers are not expensive, you can find one on Amazon.

-martin

 

[SgtAlf]

Hey Sarge,

I don't think the battery switch for the engine will light up any lights on the panel. It doesn't on my boat.

Regarding your batteries, I would put a multi-meter on each battery individually, to ensure they are all good. Look for loose connection, corrosion, etc. You can also put a load tester on each battery. Just because they show 13.5 doesn't mean they can really hold a charge. Load testers are not expensive, you can find one on Amazon.

-martin

Thanks Martin, I just ordered a Load Tester!