Battery

Any update?

When plugged into "shore power" an older converter charger charges the house battery very slowly unless it is a new "smart" charger like the PD 9245. You must have the auxiliary battery switch "on" to get charge current to the house battery. Check battery electrolyte levels, it should cover the plates.
Check battery voltage with a multimeter on the 20 volt dc range. Should read 13.6 to 14 volts with RV plugged into shore power and charger working. Check cables that run from the converter to the house battery for tight connection. Cables connect to coverter/charger with allen head set screw terminals.
There is a latching relay that connects the auxilary battery switch to the house battery. Listen for snap sound when you turn aux battery switch on or off.
The relay sometimes sticks or becomes defective with continued use.Check connectors at battery terminals for corrosion and tightness, must be kept clean and tight for good charging. If this is beyond you, have an RV service check it out and watch them to learn if possible.
House battery charging system, wiring, maintenance and troubleshooting is good to learn and will always come in handy.

Put a volt meter across the battery posts. What does it read when shore power is connected up? What does it read when the engine is running?

You need to measure the DC VOLTAGE at the BATTERY TERMINALS with a mulitmeter without the shore power turned on. A fully charged battery will read 12.6-7VDC.

Then turn on shore power and the DC VOLTAGE at the BATTERY TERMINALS should jump up to 13.6VDC-14.4VDC depending which charge mode the converter is in if it is a smart mode converter. Otherwise it should be just putting out 13.6VDC all the time.

Also check your battery terminals to be wired correctly. Look for the word "NEG" or the symbol "-" marked on the battery case and make sure this is the terminal cable that goes to the trailer frame ground.

If the battery terminals are wired wrong they must be changed to the correct position. Then look for an in-fuse close to the battery and see if it has blown. Then also check back at the 12VDC Power Distribution Panel for two fuses labeled REVERSE POLARITY. They will be off to them self. See if they have been been. Replace the blown fuses only after you have insured the battery is wired correctly otherwise you will just immediately blow them again...

If the batteries are connected properly you should be able to turn on your ceiling lights in the trailer without shore power turned on. That will tell you all the connection between the 12VDC Power Distribution Panel and the battery is good.

If the battery drains down over a few days then this is telling you it is not being charged by the converter. That is where checking the DC OUTPUT labeled +BATT is important. This will read 12.6-7VDC if the battery is connected and fully charged and should jump up to 13.6VDC when you turn on the shore power.

Here is 30AMP simplified block diagram that might help with understanding how things are wired up.



If your battery stays working for a few days then drains down I am suspecting the converter is not producing the 13.6VDC to the battery terminals for some reason. Either a bad converter, bad connections, or converter not getting 120VAC when shore power is turned ON, etc.

An inexpensive multimeter ($7-$20 from WALMART-LOWES-AMAZON-Any number of auto parts places) is a very handy tool to have tracing all of this out...

Let us know what you read...

NOTE: I live in the RV TRAILER world and realize that the motorhomes may be slightly different but the concept is still the same.

Roy Ken

2- New Batteries, 1-Lasted 2-weeks, the second one is in the RV now,

2-New Batteries, Both went dead with in two weeks, Plugged into shore power.

Reread your post. Since the battery is not being charged by 2 different charging systems, I would suspect the battery is the problem.

The converter is what charges the battery. Depending on your converter it puts out between 13.2v and 14.6v. This voltage goes thru some fuses/circuit breakers and finally ends up at the battery.

Check the voltage at the output of the converter. If it is not in this range check if the converter is getting 120vac power. If the output voltage is there, follow the wiring to the battery to see where the voltage disappears.

BTW, how do you know it is not receiving a charge?

Do you have a battery cut off switch and if so, is the switch closed? Another thought: Is your battery healthy, or is it dead? If unsure, have it checked at any auto parts store.