House batteries not charging on shore power

[jakejenny]

Help - have had a new to us 2012 Ventana LE diesel for a couple of months now. Had to have the residential refrig hooked up to the inverter and it started to work fine. Now Magnum inverter control blinks red fault and batteries are not charging on shore power. Old rig did not have an inverter and I am lost! No documentation for the inverter. Also the generator will not start even when using the boost. Assuming that the 4- 6 volt batteries are no good. Can we charge them using a charger without doing any damage to anything else? Any help appreciated!

[palehorse89]

Going to venture to guess that your charge bridge solinoid in your electrical bay that links your chassis and your house batteries together has failed........Once your chassis batteries reach a certain level of charge, the solinoid will close charging your house batteries.......
Your generator starts off your house batteries..........
Best to have all your batteries load tested to start with......first step.......

[twinboat]

Charge bridge solenoid bridges the 2 battery banks only. Has no control on inverter/charger operation on shore power.

[twinboat]

Check the circuit breakers on the inverter/charger, down in the outside compartment.
Follow a pair of large battery cables coming from the house batteries to the inverter/charger.

[palehorse89]

Originally Posted by twinboat

Charge bridge solenoid bridges the 2 battery banks only. Has no control on inverter/charger operation on shore power.

If the solinoid is bad, fridge/inverter drawing down house batteries, genset not starting......... boost switch is doing nothing.......per OP
If not working, house batteries will never see a charge.......

[Country Road]

Originally Posted by palehorse89

Going to venture to guess that your charge bridge solinoid in your electrical bay that links your chassis and your house batteries together has failed........Once your chassis batteries reach a certain level of charge, the solinoid will close charging your house batteries.......
Your generator starts off your house batteries..........
Best to have all your batteries load tested to start with......first step.......

I also think that load testing and if one is bad, replacing all if necessary and then bringing all batteries to full charge is as was said, first step. Hard to diagnose a problem if you don’t at least start with par.

[jakejenny]

Well we checked the batteries and they show very weak. We are going to start there. Currently have Trojan T-105 but having a hard time finding those locally. Any recommendations on a different brand?

[pasdad1]

The batteries at Costco or Sams club are popular because of the excellent value, although probably not as good quality at the Trojans.

Lifeline AGM are some of the best, and also good because you no longer have to check and add any water.

Check for any golf cart dealers or service businesses near you, they should have good GC2 (golf cart) batteries.

“Batteries & Bulbs” is another chain which can probably order the batteries for you (somewhat high priced)

[jakejenny]

Checked on batteries at Sams Club. Boy the reviews were horrible. Anyone used Duricell? Concerned that they will not fit on the watering system currently on the coach.

[rffowler55]

Originally Posted by jakejenny

Well we checked the batteries and they show very weak. We are going to start there. Currently have Trojan T-105 but having a hard time finding those locally. Any recommendations on a different brand?

The Trojan website has a listing of dealers by state that should help. Our off-grid solar power system on our home utilizes up to 32 Trojan T105s and they are a very dependable battery but there are other brands that will meet your needs if you are unable to locate the Trojans. I also agree to contact a golf cart supplier and see what brands they have that might have a similar amp hours and watering cap profile similar to your Trojans so you could continue to use your watering system.

[Persistent]

The batteries may have been drawn down below the Magnum emergency cut off voltage. Both inverting and charging would then not work. See "Possible Cause" below for what to do.

...it started to work fine. Now Magnum inverter control blinks red fault and batteries are not charging on shore power. ... No documentation for the inverter.

Post the model number of the Magnum inverter/converter/charger. Or search for "Magnum nnnnnnn manual". There will be a table in the manual that will tell you what the blinking light means. That will help you decide what need fixing.

Also the generator will not start even when using the boost. Assuming that the 4- 6 volt batteries are no good. Can we charge them using a charger without doing any damage to anything else?

The batteries will continue to discharge, and after time will loose capacity to be recharged. Generator will not start using dead batteries. Boost switch may not work if house batteries are dead.

Starting the generator will not charge batteries until the Magnum issue is corrected.

The RV engine alternator may charge them partially. Using the alternator may raise the battery voltage enough to restart the Magnum.

The inverter will not produce 120 volt power without 12 volts from the battery.

Shore power may still work OK, but 12 volt appliances will not work.

The batteries are not necessarily defective. There are many possible cause of charger shutting down.

You can use any high quality portable automotive charger to charge the batteries. Some must only be used while attended, some are smart chargers and will work unattended.

A 10 amp portable charger may take days to fully charge the batteries. A 30 amp charger will take about 1/3 as long, but still may take more than 24 hours to fully charge a large battery bank. Have patients?

Possible cause:
Did you run the refrigerator using the batteries and inverter?

In this case the batteries would run down in 1 to 2 days. Magnum inverter would do emergency shut down. It will not invert.

Other 12 volt appliances may have continued to discharge batteries until the Magnum charger also did an emergency shut down. It will not charge until battery voltage is brought back up.

Use a portable automotive charger to bring battery voltage above Magnum cut off voltage. (May be 11.5 volts.)

Jump start the generator or plug into shore power. Magnum will start charging again and at some point will start inverting again.

Continue to charge battery bank for at least 18 hours. They may benefit from24 hours charging.

Running 120 volt appliances using an inverter and a 12 volt battery bank requires a large battery bank, or it will only work for short periods before recharge is require.

Lots of thing to learn and possible performance issues. Google Using RV inverters.

This link seems to cover pretty well.
https://www.thervgeeks.com/what-is-an-rv-inverter/


I wish you good luck and happy trails ahead!

[jakejenny]

Lots of great advice and really appreciate it.
We did get 4 new trojan 6 v batteries but made the STUPID mistake of not taking a picture of them before removing. Now we are having trouble hooking them back up. Anybody got a wiring diagram for 4 - 6 volt batteries in a straight line?

[jakejenny]

Thanks found a golf cart dealer that carried them not to far from us.

[jakejenny]

Ok still working on getting the batteries charged from shore power. We put in the new batteries and we think? they are installed correctly. Batteries still at a 3 on the meter instead of full charge. Inverter is blinking red. When we start the MH everything goes to full battery charge immediately and the inverter turns green. Refrig is working. When we turn off the motor on the MH the inverter still is green and everything working. Batteries show 3 lights. We can start the generator but after just a few minutes the inverter blinks red and the generator shuts down. Does this sound like the charge solenoid? Is there a way to test it? We also found a block fuse that needs to be replace in the main electric bay. Any other ideas of things to check? The refrigerator is the ONLY thing on the inverter now because we shut off the breakers for everything else.
Any help is appreciated.