Any RV Inverter Gurus Here?

[Mike Andrew]

Was at my N. Wisconsin retreat(Trailer) and had issues starting my furnace and other 12 VDC stuff. 110 AC worked great but the lights were dim and the furnace just hummed. Stuck my charger on the deep cycle battery and tried again and things worked. Battery is OLD as I have electric service and run off of that.
How does one test an inverter? I did disconnect the charger and stick a multi meter on a light and kicked the furnace on. Voltage stayed at 12.8. Checked a few hours later and voltage had dropped to 12.2.Guessing things were running off of the 6 year old battery.
Are inverters serviceable/repairable or does one just buy a new one?

Any info is welcome as I do need heat Spring and Fall and do not really want to Appalachian Engineer things with my charger workaround. Though, there is a little hillbilly in everything I do up there

[RWebb]

do you have a scope?

but usually the answer is to buy a new one...

[Mike Andrew]

No scope and I believe technically it is a converter, duh.
I am looking at new ones now. Less than I expected. With luck I can find exactly the same unit and make things easy.

[tevake]

Lots of RV builders use single stage converters , these cause the batteries to burn out earlier than is nessaresary. Most owners choose to replace them with multi stage converters for better charging of their batteries.

"Best Converters " is a good shop to get the guidance for a good replacements.

Cheers Richard

[CurtEgerer]

You should be reading at least 13.6 volts. Battery is probably shot. Try that first. If problem is not solved, time for a new converter (it's a converter/charger, not an inverter). They are not really worth servicing. I just replaced a large 80amp unit for around $200. The cooling fan failed and over a period of several months, it slowly fried some of the converter's electronics. Can you hear the fan kicking on? It should run fairly frequently. I was getting flickering, dim lights, etc.

[cstreit]

Rule #1. It’s always the battery.

Rule #1 to be applied to all RV’s and motorcycles.

[Cajundaddy]

Modern batteries, charge controller, and inverter will transform your 12v system and give you a lot of detail on system health, battery charge level, current in, current out etc. If you depend on reliable 12v to “not freeze to death” you may want to upgrade before the snows hit.

[Mike Andrew]

Thanks all for the input. I will replace the battery first and proceed from there with my meter looking for 13.6 VDC on one of the lights. Always thought that the converter bypassed the battery so battery condition was not an issue and that is why it has not been replaced.
Now that it has been mentioned, I have not heard the fan running my last few trips up so that could be at the root of my problems and it is replacement time.
Looking online, I have found some "direct replacement" units for the NLA Parallax 7345 which are more modern units. Rather spend now than buy a used Parallax and do this again.
I am done up there until Spring so I have plenty of research time over the coming months.