Batteries not charging-both engine and coach

[Chuck Wheeler]

Most smart chargers will operate "current limited" into a discharged battery so the voltage will only be as high as possible within the current limits of the charger. Once the battery terminal voltage gets to the point that the current is below the charger's rated current limitthe chargerwill go to "voltage limited" operation. At this point you would see the voltages you would expect. If you immediately see 14-15 volts across a discharged battery then you have a weak or bad battery. A good discharged battery has a very low internal resistance. As batteries age this internal resistance increases.

- Chuck Wheeler-

1982 FC 31SB Fort Worth TX

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From: WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of freewill2008
Sent: Wednesday, May 06, 2009 12:26 AM
To: WanderlodgeForum@yahoogroups.com
Subject: [WanderlodgeForum] Re: Batteries not charging-both engine and coach

If the charger reads (or is expected to read) 14 to 14.5 volts, then it must be a "smart" charger. If it is a smart charger, then it should show a high voltage when connected to a discharged battery, but with no battery connected it should automatically show a lower voltage.

If the charger is not a smart charger, then disregard.

In either case, you might try disconnecting the the battery bank(s)from the bus and borrow/beg/rent/buy a 40-50 amp portable charger that has a battery reconditioning function to see if you can bring the batteries back. I've had some good luck with this, getting extra months or years from batteries that had experienced a complete discharge.

The corollary to trying a reconditioning charger on the batteries is to try a different battery on the charger. Any available partially discharged battery connected to the bus charger will tell you if the charger and isolator are working. Use a specific gravity tester to see if the battery gets charged. (Also, use the tester on the bus batteries to see how badly discharged they are.)

Finally, going back a step or two, did you check the voltage at the batteries with the charger on/charger off? If the voltage at the battery post(s) does not go up when the charger is turned on, then there is a problem with the charger or between the charger and the batteries.

Bob Griesel '84 FC31 WLII WA

--- In "WanderlodgeForum%40yahoogroups.com", "Ed Gardels" .> wrote:
>
> --- In "WanderlodgeForum%40yahoogroups.com", "Ralph L. Fullenwider" wrote:
> >Ralph, Thanks for the input. Yes I put a meter on the contact of the bosch relay and read 4-5 volts. I then remove the + wire from the charger and get 13v, go figure....
> Ed Gardels 89SP
> Arlington Tx
> > Hi Ed:
> >
> > Just a curious question to start; Have you checked the output dc voltage
> > from your chargers? they should be reading 14.1 or so dc volts at the
> > source. If only reading 12.3 vdc then the chargers have taken a hike on you.
> >
> > Safe travels,
> >
> > Ralph and Charolette Fullenwider
> > 84FC35 "Ruff Diamond"
> > Duncan, Oklahoma
> >
> > At 05:01 PM 5/5/2009 +0000, you wrote:
> > >--- In "WanderlodgeForum%40yahoogroups.com", "Chuck Wheeler" wrote:
> > > >Thanks for the response, Chuck. Actully i tried that a couple of weeks
> > > ago, but the chargers didnt keep up. Its the first time that the engine
> > > batteries went down too. I think that a clue to my problem, since it
> > > deals with both seperate banks of batteries. I have also tested the
> > > battery isolator. I have exausted my ideas.
> > > Thanks
> > > Ed Gardels 89SP
> > > Arlington Tx
> > > > Ed,
> > > >
> >
>