Community Forums

sgtjoe · 03-12-2025, 10:21 AM

I have a 2001 Tradewinds and am trying to figure out why my 2 engine 12V batteries go so dead that they need to be replaced. My MH sits for months here in St George Utah. I'm wondering if the inverter or something else is draining them. The inverter was replaced since we moved here 7 years ago. I never had these batteries drained like this when we lived in Salt Lake City area. We would leave for the winter in October and stay in the Yuma area for 3-5 months parked at the same Camp Ground all that time and never had the Engine batteries drained like they are doing here. Could something have been miswired when the inverter was replaced that is draining the engine batteries?

OldCoastG · 03-12-2025, 10:44 AM

I unhook all the batteries when I store my motorhome...aways have. you might try unhooking them.

Soppy · 03-12-2025, 11:01 AM

If you are plugged into shore power, it's possible they are not being charged due to a malfunction of the charging circuit.
I always disconnect my batteries when the motorhome is not going tobe used for a couple of weeks. Never had a dead battery.

NoviBill · 03-12-2025, 06:35 PM

Is anything plugged into your power outlets (cigarette lighter)?

sgtjoe · 03-17-2025, 11:17 AM

I was given replacement batteries from NAPA under warranty and before I install them I'm wondering if something was installed wrong on my Inverter causing a draw on the Engine 12v batteries. Does anyone else with a 2001 National Tradewinds 7390 experiance dead Engine batteries if they leave them connected?

How long can I leave them connected if not using the MH??

Flyer15015 · 03-17-2025, 11:36 AM

Sarge,
Do you have salesman switches? Are they off when you store the coach?
If they are off, use your multimeter and check both sides of your fuses for the drain to isolate the system that is the problem. Report back.

I too disconnect all batteries when we store the coach more than a week.

Mike in Colorado

wolfe10 · 03-17-2025, 11:59 AM

The inverter and/or inverter/charger should ONLY be connected to the house battery bank, not chassis battery bank.

Only way an inverter could draw down a chassis battery is if the inverter is connected to that bank OR the boost switch is left on which would draw down both battery banks.

As asked, are you on shore power??

sgtjoe · 03-18-2025, 11:22 AM

Don't laugh I'm just getting older, here is a question. Do I connect my 2 12v chassis batteries negative to negative and pos to pos? And when the MH is not going to be used do I disconnect all 4?

wolfe10 · 03-18-2025, 01:23 PM

Quote:

Originally Posted by sgtjoe

Don't laugh I'm just getting older, here is a question. Do I connect my 2 12v chassis batteries negative to negative and pos to pos? And when the MH is not going to be used do I disconnect all 4?

Yes, you will connect the positive of battery #1 to positive of battery #2.

Connect negative of battery #1 to negative of battery #2.

Connect house positive to positive of one battery and negative to house to the other.

Yes, when not in use, you can disconnect the batteries and/or if you have shore power and a smart charger/maintainer OR solar and smart controller.

SafariBen · 03-18-2025, 02:30 PM

No need to disconnect all four terminals of two parallel chassis batteries. Disconnecting both negative terminals will prevent any EXTERNAL battery drain. Disconnecting the ground cable so the two negative terminals are still connected to each other would allow one bad battery to drain the other one, IF one goes bad.

mbrandt1402 · 03-19-2025, 06:44 PM

Let me address your question about the inverter draining the engine batteries: if your battery and electronic bays are laid out similarly to my '04 TropiCal, it would be extremely unlikely unless they also replaced inverter to battery cables and hooked them up incorrectly. From National, there are no engine battery cables near my inverter.

The simple test would be to disconnect all of the "+" cables at your engine batteries and see if your inverter works. If properly connected to the house batteries, it will still work and your power drain is elsewhere.

Our TropiCal is on shore power virtually 100% of the time it is not being driven. I check to see that the inverter/charger is on "Float charging" and that is all. All of my batteries are AGMs, so no need to water the batteries.

Gene O · 04-10-2025, 03:59 PM

I have a 2007 Tropi-Cal T330 and had the same problem. After having the electrical trougleshoot, my alternator was not charging the batteries, and also were discharging my 2 12v chassis batteries. Had the alternator replaced, and so far the batteries are keeping its charge.

shootist · 04-10-2025, 04:11 PM

Quote:

Originally Posted by Gene O

I have a 2007 Tropi-Cal T330 and had the same problem. After having the electrical trougleshoot, my alternator was not charging the batteries, and also were discharging my 2 12v chassis batteries. Had the alternator replaced, and so far the batteries are keeping its charge.

Leaking alternator diodes will drain your batteries. Simple test is to start it up, put your volt meter on AC voltage, + to alternator output ( chassis batteries) and - to ground (chassis batteries) if you read more than 10 or 15 milivolts your diodes are going bad.
The alternator may still charge when running but drains the batteries when parked.

Mark_K5LXP · 04-10-2025, 07:02 PM

Wonder and guess or measure and know. You've declared the inverter installed some years ago the culprit. When you do that you aren't paying attention to clues that can lead you to where the problem really is. You start with measuring battery current when everything should be off, and observing when that current changes or goes away when disconnecting or unplugging circuits via relay and fuse panels. It won't be long before it's down to a couple or just one circuit or system and the fault or issue determined.

Mark B.
Albuquerque, NM