Power Center/Converter Not Charging

[kxrwilli]

2009 305RLT - power center/converter appears to not be charging the 12 volt battery. Replaced battey with new one reading 12.7 volts. After about 12 hours the new battery was very low. Put external charger on new battery and was able to power 12v items (furnance and lights) and recharge the battery. I checked the breaker that was labeled Conv - it ws not faulted but I reset it anyway. Where is the onboard charger located? Is it part of the power panel in the image. Is there anything else I shold do to validate the function of onboard charger? I currently have a 3 amp battery tender on the battery - will that allow the battery to maintain a charge while running the furnance?

Apprecaite any advice. Need to get this resolved for proper furnance operation in this cold weather.

[JRTJH]

Many things to consider, but first, welcome to the forum...

1. What trailer line is your 2009 305RLT ?? Keystone often uses the same "model number" on various brands in different years. So a Cougar 305RLT would/could be significantly different than a Montana 305RLT. What brand is yours ???

2. You say you recently changed out the battery. There are two "reverse polarity" fuses that in years past, were mounted on the end of the converter/charger. More current years, those fuses are mounted on the DC distribution panel on the power center faceplate. It looks like from your photo, that your reverse polarity fuses are on the converter/charger unit. On travel trailers it is often located either mounted on the power center rear cavity (behind the circuit breakers) or to the trailer floor behind the power center. On fifth wheels, it may be in the same location or it may be "buried in the space behind the front passthrough.

The purpose of the reverse polarity fuses is to "instantly open" to prevent electronic component damage in the event the battery is momentarily connected incorrectly. in other words, if the neg or pos battery cables touch the battery terminals in reverse polarity. And that does mean "instantly".. If the reverse polarity fuses are blown, then battery charging stops until they are replaced.

3. If you connect "any additional voltage source" to the battery, that voltage is "sent to the converter/charger" and will shut down the charge current to the battery. Battery charging is managed/controlled by monitoring the battery output voltage and adding an extra charger will "falsely send a full charge voltage" to the on board charger monitor circuit... So, your 3 amp trickle charger will "shut down the main charger" even if the reverse polarity fuses are intact.

4. Whether a 3 amp trickle charge is enough to keep the battery charged depends entirely on how much drain the furnace and other trailer DC load is being placed on the battery. If, as an example, the 24 hour charge (3x24) is 72 amp/hrs and your trailer draws 70 amp/hrs from the battery, then it will "manage to provide enough power". On the other hand, if it's a particularly cold night and the furnace runs for longer times, the trailer load on the battery may be 75 amp/hours and you may have a dead battery since the charger is only providing 72 amp/hr into the battery...

So, you might have enough power to keep the battery charged with that charger and on the other hand it may be inadequate, based on the "real battery drains" ... There's no way to know what that actual requirement is because it will change based on multiple factors, mainly by how long the furnace runs on any given night....

I'd find your converter/charger, make sure the reverse polarity fuses are intact, then make sure the electrical cables on the battery are clean, tight and not corroded as well as checking the other end of the negative cable, where it is screwed into the trailer frame, to make sure it's also tight and making good contact.

I'd suspect, at best, that 3 amp trickle charger is "bare minimum" for your needs and probably is making the current charger "shut itself off" if it's working properly.

[NH_Bulldog]

That model has a separate "deck mount" converter. Since the converter typically plugs into a receptacle on the back of the distribution panel, I would look under/behind that power center and look for the converter.

You can test the output of the converter (even before you find it), by disconnecting the converter wires from the battery/batteries and measuring the voltage with no load on the system. You should have at least 13.6v DC coming from the converter. If you have less, or nothing it all, then the issue is your converter, the reverse polarity fuses on the converter, or the wiring between the converter and the batteries (maybe a rodent had a snack?). However, I would say that based on age alone, the converter (which the brand is not all that reliable to begin with) has failed. If you do need a new converter you might want to look into Progressive Dynamics and future-proof your purchase since they are very reliable and have models that can charge various types of batteries.

[ChuckS]

Easy to follow troubleshooting chart for your WFCO converter

https://www.wfcotech.com/wp-content/...800-Series.pdf

[kxrwilli]

Appreciate. Problem resolved by replacing converter.