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subtroll's avatar
subtroll
Explorer
May 20, 2018

Tropi-cal Coach Battery Charging Problems

Our 2004 National Tropi-cal has been idle for the past six months but plugged into 50 amp power with inverter/charger continuously on line.(as we have done last 15 years). Began traveling 4 days ago and are now in North Carolina. At our first stop we stayed at a mountain lodge and left the coach in the lot without any available electrical input. Planned to run generator for short period each day to keep batteries up.

First day noticed Generator was not charging Chassis batteries... always has in the past. Also noticed during charge of house batteries the generator load seemed to shift up and down but that may have been the refrigerator cycling. Left coach last night with house batteries ~12 VDC. This morning house batteries were below 11 volts and not sufficient to start generator. My dash Boost switch also didn't allow me to start the generator.

Driving 100 miles today the alternator did not charge house batteries...always has in the past.

I suspect my problems are with my 2000 W Xxantech (458?) inverter/charger which won't energize now with low battery voltage and no external input. I inspected the front panel connections for Krispy criters but saw nothing obvious. I plan to look for assistance in Gastonia and Ashville, NC tomorrow (motel tonight)

Any thoughts/ suggestion appreciated.
Class A
  • subtroll's avatar
    subtroll
    Explorer
    May 22, 2018
    We parked today at a RV park and connected shore power. I reset my Xantrex 458 inverter/charger and all systems appear normal. Both sets of batteries are now fully charged. I will test and follow the charging systems during three more travel days this week to see if anything is not working right. Thanks again for the suggestions and help.
  • pianotuna's avatar
    pianotuna
    Nomad III
    May 21, 2018
    If a diode isolator is in use replace it with a relay.

    If a relay is in use, check the fuse for continuity. If the fuse is good, then it may be that the contacts are burned.
  • wolfe10's avatar
    wolfe10
    Explorer
    May 21, 2018
    subtroll wrote:
    I My alternator is working fine 13.6/8 VDC during charge and it recharges the chassis batteries fine but not the house batteries.

    Thanks for inputs.


    That suggests your battery isolator is faulty. Could be a relay or diode-based isolator.

    Doug indicated that yours has a relay (bi directional), so that is where I would start troubleshooting with a voltmeter.
  • subtroll's avatar
    subtroll
    Explorer
    May 21, 2018
    I watered the batteries during my pre-travel maintenance. Batteries are about 4 years old. My alternator is working fine 13.6/8 VDC during charge and it recharges the chassis batteries fine but not the house batteries. All VAC systems worked fine for 400 miles on first day until we parked at the lodge. Ran both roof A/C, refrigerator and water heater on generator. I'm getting a new set of tires on Monday and then will stop at an RV park and get shore power. Until then I have no charging source to restore house battery voltage. I thought that was the way the boost switch functioned but was hoping it also worked in reverse. I didn't realize my generator started from the house batteries not the chassis. Still plenty to learn after 15 seasons and 154k miles.

    Thanks for inputs.
  • Sam_Spade's avatar
    Sam_Spade
    Explorer
    May 20, 2018
    Sounds pretty much like what happened when my "battery solenoid" failed.....in BOTH of my last two RVs.

    Pretty common failure and not expensive to fix.
  • 2oldman's avatar
    2oldman
    Explorer II
    May 20, 2018
    How old are your batteries? Do they have sufficient water?
  • dougrainer's avatar
    dougrainer
    Nomad
    May 20, 2018
    1. Your dash Boost switch is energized by the COACH batteries. So, if low and not enough to engage the boost solenoid, that is your problem
    2. From your description of the storage time, Have you checked the Coach battery water? I suspect they boiled from long term storage
    3. HOW old are the Coach batteries
    4. Cannot remember about the 458 Freedom, but some Inverter/Chargers will not engage the Charger function when 120 present if the battery voltage is below 10 to 11 volts. You must either use an external source to get a temporary line voltage to 12 volts for 5 to 10 minutes and then the Inverter/Charger will come on line to charge
    5. National used a Board assbly, usually in a Storage compartment by the entry door, that had the Bi directional and Boost relay's mounted in that panel. With various fuses. 14 years and one of those relay's failing would not be unusual. This assbly controls BOTH the Chassis charging the coach and the Boost going to the chassis battery.
    6 The boost is designed for latching the Coach to the chassis to start the chassis engine, not the other way. That is why if the coach batteries are dead/low, the system does not function. Doug
  • wolfe10's avatar
    wolfe10
    Explorer
    May 20, 2018
    And, as far as generator (or shore power for that matter) charging the batteries, I assume all other 120 VAC stuff worked (like roof A/C's). If so, check that the breaker for your inverter/charger has not tripped (on main 120 VAC breaker panel).
  • wolfe10's avatar
    wolfe10
    Explorer
    May 20, 2018
    Very unusual that both the inverter/charger and the engine-driven alternator would both quit charging at the same time.

    Need to grab your voltmeter and see what is going on. For the engine part, start by taking readings at the BATTERY ISOLATOR with engine off and then running and with engine around 1000 RPM (use cruise to bump up idle speed). Write down readings at each of the lugs.

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