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Topic: Battery Problems (Read 612 times) previous topic - next topic

Battery Problems

I just bought a 2000 U320 4000. Great coach but I'm having Battery problems. I'm plugged in to 110 at storage, boost switch off, charger on, three new start batteries. When I go to start it, I have to use the boost switch every time. So I took it for a two hour drive, everything went great until I got back to storage. I turn it off and tried to restart it and not only was the start batteries dead but so were the house batteries or so them seemed. I started the generator, it started right up, so I tried to start the coach and it started right up like my batteries had a full charge. The generator had not been running more than 15 or 20 seconds before I started it. Not enough time to charge anything. Anyone know what is going on here?

Re: Battery Problems

Reply #1 –
Start by checking battery cables to and from the engine/chassis batteries.

From the factory, the chassis batteries are not charged from shore power/generator.

With your no start after driving, you have either bad connections and/or alternator/charging issue.  After connections, the battery isolator is a good place to test this.

Let us know what you find on the cables and we can then direct you on how to test the engine charging system with a digital voltmeter.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Battery Problems

Reply #2 –
Leaving the engine batteries any length of time will discharge them because of the parasitic draw on them. A flat AGM may not want to be charged again and if it does recharge it may lose some capacity. I just made a jumper with 5 amp fused plugs on both ends and go from the dash lighter plug to the HWH panel lighter plug. It keeps the engine batteries about the same voltage as the house. I also put twin voltmeters right above the dash lighter so I can see both voltages. I leave the LED voltmeters on 24/7 so I just have to pop my head in the door and it can see the voltages. I did this about 12 years ago and it's been working like a champ ever since.

And no, the jumper never even gets warm. If we are camping for more than a couple of days, I plug the jumper back in.

Pierce

Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Battery Problems

Reply #3 –
Pierce,
We don't have a lighter plug on our HWH panel, is that something you added?
There is another lighter plug under the dash (bottom, facing the floor) of the passenger side.
Not user friendly due to location.
I assume they are both connected to chassis batteries.
Frank & Connie Williams
1999 U320 '36
Build: 5466
MC: 18335

Re: Battery Problems

Reply #4 –
Quote from: Pierce & Gaylie Stewart –
I also put twin voltmeters right above the dash lighter so I can see both voltages. I leave the LED voltmeters on 24/7 so I just have to pop my head in the door and it can see the voltages.
I took Pierce's advice and installed two inexpensive LED volt meters on my dash.  This is a GREAT tool for monitoring battery bank condition.  Every time I step into the coach the first thing I look at is the volt meters.  Any charging problem would be immediately obvious.

What did you do to your coach today VI
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Battery Problems

Reply #5 –
Quote from: Phranko –
Pierce,
We don't have a lighter plug on our HWH panel, is that something you added?
There is another lighter plug under the dash (bottom, facing the floor) of the passenger side.
Not user friendly due to location.
I assume they are both connected to chassis batteries.
Thanks Chuck! Nice installation.

Phranko, never assume anything as our coaches are like snowflakes, none seem to be the same. Bill's ex-coach and ours should be exactly the same but only close.


Using a voltmeter, check to see if both are chassis. The existing lighter plug on the dash is engine battery.  No, our coach came stock with the HWH plug. Easy to add another plug by just finding a under dash chassis 12V source and installing a plug anywhere you like. The start solenoid located by the steering column is engine/start battery so a good place to take off 12V for driving light relay, radios, lighter plugs. Disconnecting start batteries before working with the solenoid is the safe way to do it. Schematic will show where the chassis 12V is under dash top. If you install another lighter plug, make sure it's fused.

A fire could and has happened with wiring under the dash where it was installed to link the two battery systems. Best to do like I did with protection both at the lighter plug and at each end of the jumper wire. My jumper has 5 amp fuses at each end in the plug so they will blow well before any short could cause trouble.

In no way is this intended to charge a dead or partially charged battery. It is only intended to maintain a charge.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)