Newbie Battery Question?

I would not assume that your meter is accurate enough to worry about a couple tenths of a volt . I own 4 volt meters and they never agree . Do not worry so much until you have a problem . Check the water on a regular schedule and enjoy your trailer .

Thank you RoyB that is what I was worried about boiling out the battery acid so if I am hooked uo to shore power for more than a couple of days I will just unhook batteries and will lok inti the converter you mentioned

It seems everything is doing what is expected. When you plug your trailer into a 120VAC Shore Power Connection then the on-board Converter/Charger will charge your battery. The 12VDC output of the converter/charger is most likely a single mode charger and will produce a constant 13.6VDC DC Charging voltage to your battery bank. This will eventually increase to 13.6VDC while being charged.

This appears to be normal for your converter/charger.

This 13.6VDC however is right at the point of boiling out your battery battery fluids and the batteries fluid levels should be checked at least every two weeks if continuously left plugged in to shore power.

Replacing your converter/charger with a smart mode charging technology unit will resolve this situation. If you are worried about not being able to look at your battery fluid levels on a scheduled basis then I would disconnect the negative battery terminal when being stored.

just my two cents

Roy Ken

Were those 12volt batteries new? If so I would consider returning them. 12.1 volts around 50% discharged and depending on long they have been that way they could be significantly sulfated.

Normal reading plugged in shore power for most TT is around 13.6 volts. Your 13.1 means they are still charging but they will take a really long time at that level. You need to get them up to 14.4 to 14.8 for several hours.

A fully charged 12volt battery at rest for several hours should read 12.6+ volts

Definately leave your batteries hooked up when hooked to shore power as this is what charges the batteries as well as when it is hooked up to your tow vehicle. Your fully charged batteries will read 13++ volts.
happy travels.