Converter charging Batteries ?

[rdjensen]

I have a 2003 Georgetown 30' MH

When I plug into shore power my voltmeter is only registering at 12.08 volts, when taken at the two 6volt trojan batteries.

It will also register at this or close to it when the generator is running.

When I start the MH engine the coach batteries readings are the same, but the chassis battery is registering over 14 volts.

The batteries are testing at 1.225 specific gravity of ~ 75%.

I have a parallax 7455 convertor (not the two stage one)

When I am plugged in or having the generator running shouldn't it be putting in more volts than 12.08??

Shouldn't I be getting 14 volts when starting the engine for both set of batteries not just the chassis ones?


I am also wondering how my batteries can read 12.08 volts which is 50% while the hydrometer reads 1.225 which is 75% ??


Perhaps I need a better convertor or charger.

Any suggestions and help is appreciated.

[Bama Rambler]

Sounds like the charge side of your converter isn't working properly. It should supply more than 12.08 volts.

Your house and chassis batteries are separate. That keeps you from running down your cranking batteries with the house loads.

Your alternator charges your chassis batteries but not your house batteries unless you have a switch that allows it.

[rdjensen]

I thought the alternator also charged the house battery. Isn't driving supposed to charge it up?

[sparks1032]

We had a switch go out and by switch it is the mechanism that separates the house batteries from the coach batteries and to charge the coach batteries when driving. SO my recommendation is to see if that switch is not working properly. I was told by our service guy that they do go out frequently.

I was able to tell it was not working properly because when we ran the RV the coach batteries would read 100% (charging) when the switch broke when the RV was driving or running the batteries were not charging (took awhile to figure out as the batteries were well charged). HOWEVER our coach batteries would still charge when plugged into shore power. Hope this helps!

[NWJeeper]

Originally Posted by rdjensen

I have a 2003 Georgetown 30' MH

When I plug into shore power my voltmeter is only registering at 12.08 volts, when taken at the two 6volt trojan batteries.

It will also register at this or close to it when the generator is running.

When I start the MH engine the coach batteries readings are the same, but the chassis battery is registering over 14 volts.

The batteries are testing at 1.225 specific gravity of ~ 75%.

I have a parallax 7455 converter (not the two stage one)

When I am plugged in or having the generator running shouldn't it be putting in more volts than 12.08??

Shouldn't I be getting 14 volts when starting the engine for both set of batteries not just the chassis ones?


I am also wondering how my batteries can read 12.08 volts which is 50% while the hydrometer reads 1.225 which is 75% ??


Perhaps I need a better convertor or charger.

Any suggestions and help is appreciated.

Sounds to me like the charging side isn't working. Have you checked the fuses on the unit?

Also, the Parallax chargers are 2-stage only. The "T" option (if you have it) only adds the ability for the charger to maintain 13.6 volts for a timed period instead of droping off the voltage. This only boils the batteries instead of properly maintaining them.

Trojan's own documentation states that to properly care for their batteries you must "equalize" them at least every other month with a charge voltage of between 14.4 volts and 15 volts. This "overcharging" is what truly brings deep cycle batteries up to 100% charge, nothing else will.

I would highly recommend the Progressive Dynamics 9200 series converter/chargers. The price is better than I thought it would be and they are a good 3-stage charger. I have had mine for a couple of months now and have been very happy with it. I know my batteries are happier and better cared for now.

[mbtelguy]

Your problem description invites a lot of Questions:

1/ Have you obtain, from the Parallax web site the trouble shooting procedures
for the 74NN converter series. If not, before throwing out your converter maybe try
the recommended tests.

http://www.parallaxpower.com/7400/Flowchart7400.pdf

2/ Do your various 12V lights, water pump, etc. work without shore power and/or the generator running. If they do not make sure the battery disconnect switch is in the connect mode. Note do not relay on the Battery switch light it will be on any time the
converter is operating.

3/ I’m not as familiar with FR vehicles as some on this forum but if you have a boost switch on the dash you most likely have what is called a Battery Control Center and in the BCC you will find the switches (actually there are solenoids) that sparks1032 referred to. A loose connection on a solenoid or a bad solenoid may explain why you do not see the 14Volts from the chassis charging system or a charging voltage from the converter.

4/ Also with in the BCC there is various fuses and circuit breakers you may want to check. In particular the reset-able circuit breakers.

The problem as you describe it lends itself to something that is common to both the chassis and coach charging systems, eg. The BCC, but assuming anything with out further information, would be taking the WAG approach to your problem