Battery not charging

[PatsyG]

The stereo indicates that the batteries are low, the Garman says low voltage and the VHF is not what it should be. Our boat is constantly on shore power and we do not understand what’s going on.

 

[trailertrawlerkismet]

Check the simple things first. Does your electric panel show you’re getting power from the shore power? If so what does the charger gauge show as the status of the battery charge? Full charge, absorption, etc? What does the volt gauge show for battery volt status after you turn off shore power after a half hour? Can you switch between the house batteries n the start battery to check it’s volt status? How old are the batteries? If 5 years or older they may need to be replaced. Have you taken the battery cables off of each battery terminal, clean both the post and cable and apply some dielectric grease n reconnect. This is where I’d start. Please let us know what the final solution is.

Jim

 

[Pilotnavigator]

one more time, everyone get a good DC clamp meter, about a hundred bucks, then you can measure the current going into a battery and measure the current for each line going to devices. This is the only way to understand what is happening with your batteries.

 

[Crewdog]

2 things to check and make sure:

- Is the battery charger onboard the boat functioning properly? It should have an indicator showing how many volts it's putting out. We found on purchase inspection that battery charger was cycling constantly on shore power; dealer replaced and all has been fine.

- Check the thermistor cable from the start battery to the charger. If it is malfunctioning as ours became last year, it will not let the charger put out any voltage. simply remove the cable from the charger and see if all is well. then a new thermistor can be had from the charger manufacturer. they sent us one for free.

Good luck!

 

[captstu]

If you have a voltmeter and is reading 13 V or below, it may mean that your battery charger has taken a vacation.

I’ve replaced mine twice until someone told me that it has to be turned off 10 or 15 minutes every two weeks or so.

If you use the boat regularly this process is automatic.

While this doesn’t make sense it has kept both my battery charger and batteries working fine for several years.

 

[knotflying]

Things to check if you have the promariner combi

First - There is a switch that goes from the inverter to the batteries. This is also the positive lead to charging and must be on.
Second - Is your rocker switch for the inverter/charger in the up position? this needs to be up when on shore power for charging.
Third- See that the charger is working. Turn the inverter switch off in the battery compartment and then hold a volt meter to the plus and minus terminals on the combi going to the battery. You should be reading 13 Volts
Fourth- How old are your batteries?

Report back with findings.

 

[ShortCut]

one more time, everyone get a good DC clamp meter, about a hundred bucks, then you can measure the current going into a battery and measure the current for each line going to devices. This is the only way to understand what is happening with your batteries.

John (Pilotnavigator) - I finally took your advice and bought a good DC Clamp Ammeter. I found a great meter on Amazon for only $45. It has over 200 amazon reviews averaging 4 1/2 stars and some of its YouTube reviewers compare it favorably to meters costing more than $150. The meter is "Signstek UNI-T UT210E Handheld RMS AC/DC Mini Digital Clamp Meter Resistance Capacitance Tester". I just received it, and it checks out to near perfection. Too many posts refer to current-draw mysteries, and I agree that a DC Clamp Ammeter is an essential tool for these boats.

Marshall

 

[Pilotnavigator]

You will enjoy it! You can check any line now without taking apart conectors etc. Once you know the actual current draw of each device, and the output of any solar devices you can calculate you total daily amp hours used and produced and then match your battery capacity to those needs based on the number of days you want to stay on anchor.