is the convertor supposed to charge the batteries?

KJINTF wrote:
I agree the OP has a problem

Which could be the 7300, btw 7300 series do NOT have 50watt ceramic resisters.
That converter can easily be tested and quickly be repaired if defective. Check the 120Vac input and that it outputs 13.6Vdc under a load. If under a load the voltage drops check the 25Vdc 2,700ufd cap under the heat sink and the four current sense resisters. <$5.00 in parts and at most 15 minutes you will be back in business with a nice single stage 13.6Vdc power supply. Lost count on how many of them I've repaired over the years - they make really nice 12Vdc bench supplies.

If not worried about charging your batteries from a generator in a short time the 7300 series is a good single stage converter - just keep an eye on the water level.

That's refreshing ... a voice of reason. Yes, RV converters can charge and keep charged, an RV's batteries.

However, the first converter in our new RV did fail and have to be replaced with a second converter under the RV's warranty. It failed in an unusual way - which may be what the OP is experiencing. Our RV's original Parallax 7345 converter still output 13.8 volts, by at only a very low current load - enough to run some stuff in the RV up to a total current load of around 8 amps. More load than that and the bad converter's output voltage would begin to drop - so much so that the RV batteries were not getting charged - just like the OP's situation.

Our second Parallax 7345 converter has supplied 12 volt power and taken care of our RV's 200 amp hour AGM battery bank just fine for around seven years. Here's some comments explaining why and how:

1) Our eight-year-old AGM batteries are to be floated at 13.5-13.8 volts ... NOT 13.2 volts. It says so right on their label.

2) Our Parallax 7345 output is 13.8 volts ... not 13.6 volts.

3) Our AGM batteries can be boost-charged at 14.4-14.8 volts ... but don't have to be if you don't need the shortest charge times possible.

4) Our Parallax 7345 does not inject noise onto the TV, the computer, or the radio.

5) We generator-charge with the 7345 for around five hours per tankful and can get away with it because the very small generator we use is so quiet and low-frequency sounding.

6) If we must generator-charge quickly or more thoroughly, I use both the Parallax converter plus a cheap Sears 120V battery charger together at the same time with the small generator for a couple of hours to bring the AGM batteries up closer to 90% in just a couple of hours.

7) The no-longer-available Parallax 73XXT series double stage converters seemed excellent for my needs ... too bad you can't get them anymore.

8) I do keep our AGM batteries on the converter for months at a time whenever the RV is in storage ... so the AGM batteries are kept at full charge.

9) The engine alternator easily brings the AGM batteries back to very close to 100% with 5-6 hours of driving. I can see this on the permanent ammeter, as it's current flow into the batteries reading shows a value of zero.

10) We do not drycamp days on end without some driving time between campsites, so on long RV excursions the batteries do periodically get a full charge.

IMHO, the Parallax 13.8 volt converters are not a junk piece of RV equipment (their price is up there right along with other power supplies), they just are not the best for liquid acid RV batteries if the user doesn't know how the converter and batteries are to be used together.