IS 12.8V good after a night on the house bank?

[jagizzi]

I would like to confirm my thoughts that 12.8V is good after a night on the house bank with the fridge and lights going.

The only reason I have any concern is that the solar panel battery panel shows a low voltage max for the house bank of 9.6V. The boat is new, and my guess is this is a remnant from install, and can be ignored, or considered innaccurate.

A secondary question is: Does anyone know how I can reset that panel to remove that reading so that I can establish a new minimum?

The boat is a 2018 R23 and the panel is in the quarter berth below the cabin seating, next to the power panel.

 

[Cutwater28GG]

so it depends if you have 12.8 whilst charging, under discharge load or with no load (almost impossible in a tug as there is always load on the house batteries)

if you are still on the hook, no generator and no shorepower with engine off 12.8v is amazing! (note voltage is slightly higher for SOC on AGM batteries from what I read but its marginal)

seeing as this would likely be that the battery is at 100% I am skeptical this is a no load measurement after a whole night on batteries...

 

[NorthernFocus]

Presumably you have AGM batteries as 12.8V is 90 percent charge for AGM but greater than 100 percent for standard flooded lead/acid. So if AGM then yes, still having 90 percent after a night on the hook is doing pretty good.

 

[knotflying]

You are just fine with 12.8V after a night on the hook. Actually, that is quite good. I am happy with 12.4V. To reset your mornigstar history press the two arrow buttons simultaneously and it will clear all history.

 

[jagizzi]

Good to know, I appreciate the responses. Thanks for the reset instructions.

 

[Dale777]

jagizzi,

Something is puzzling about your comment of: "I would like to confirm my thoughts that 12.8V is good after a night on the house bank with the fridge and lights going."

I would think that the voltage should be far less than 12.8 afterwards. Did you check the voltage after sun up when the solar panel was charging the batteries? If so, then you are seeing the solar charging voltage, not the actual state of charge voltage of the batteries "...after a night on the house bank with the fridge and lights going."

Am I missing something about this?

 

[knotflying]

Dale is correct. After I read the post again I started to think that 12.8V is actually a full charge. After a night on the hook it should be below that. To get a more accurate state of charge you should turn off as many of the items drawing current and also disconnect the solar panel or at least check the meter before sun up. Historically I have always been around 12.4V after a night. This is running the refrigerator at a 2 setting, charging phones,etc, some lights perhaps a movie on the DVD and my C-pap. I have my thruster battery joined so that will make a difference as well.

 

[jagizzi]

So that is in the morning but yes the solar panel is hooked up and likely charging.

I was off the opinion that the panel showed the hi, lo and current value of the battery string being indicated, and then also the solar charging voltage as well.

Clearly I will have to do a bit more reading on this part of things.

As an aside I noticed that you said you ran a CPAP all night. Do you go 12v or run off the inverter. The CPAP is my next test for the batteries but I was a bit worried it would be too much.

 

[knotflying]

So that is in the morning but yes the solar panel is hooked up and likely charging.

I was off the opinion that the panel showed the hi, lo and current value of the battery string being indicated, and then also the solar charging voltage as well.

Clearly I will have to do a bit more reading on this part of things.

As an aside I noticed that you said you ran a CPAP all night. Do you go 12v or run off the inverter. The CPAP is my next test for the batteries but I was a bit worried it would be too much.

There are several bits of information derived on the remote meter. Read through the manual and it will describe each step. The directions are not the best, but I am sure you will figure it out.

The C-pap does not draw much power. I only use the inverter when we are using the microwave or other high power consumer and I will have the engine running while using it so I do not drain the batteries. For the c-pap I use one of those cigarette lighter plug in's of 75 watts or more.