National RV Dolphin not charging batteries

[map40]

I have a 36 class A that sometimes it doesn't charge the coach batteries. Even when plugged in, the batteries get low. If I jump them with the engine battery, suddenly everything is OK, even after I take the jumper out, suddenly the 12v charging system works, and the batteries start charging again. Any ideas?

[MrWizard]

a converter is a charger
and unless someone specifies 'portable battery charger'
he usually means 'converter'

the word 'converter' is a carry over from the earlier decades
where it was NOT really a charger for the batteries, but just a means of supplying 12v instead of battery, when shore power was available

in the present sense of the word, it means charger

thats why when look up converters on the web or in catalogs
you see the words 'smart charger'

[hostage]

map40 wrote:

I rv wrote:
make sure you have power (shore power)to the inverter/charger and all connections are clean and tight.If the charger is bad,mine was,I got a 50 amp rv 3 stage charger from ebay for about $100.00 and just hooked it to the batt. lugs on inverter.I disconnected the 110 volts from the charger/inverter and and put a receptical in that bay plugged in the new charger and works fine and the intelec panel inside still works. good luck

So you just connected the charger to the batteries? I was going to do that, but I was afraid on the charger feeding power back into the converter. Any comments?

how could the charger feed back into the converter and second off if the converter is shot then would one not simply remove it??? better yet why not just install anew converter rather than waste time with a charger

[MrWizard]

i think he means he removed the old converter from the bay
took the 120v line that was hardwired and put in a receptacle to plug in the new converter

as far as the your old converter
it might be safe to do that
but its safer to remove it
if its stand alone
if its part of the circuit breaker fuse panel
you can get a replacement unit, you just remove the charger section and put in the new one

what is brand and model number of your converter

[map40]

I rv wrote:
make sure you have power (shore power)to the inverter/charger and all connections are clean and tight.If the charger is bad,mine was,I got a 50 amp rv 3 stage charger from ebay for about $100.00 and just hooked it to the batt. lugs on inverter.I disconnected the 110 volts from the charger/inverter and and put a receptical in that bay plugged in the new charger and works fine and the intelec panel inside still works. good luck

So you just connected the charger to the batteries? I was going to do that, but I was afraid on the charger feeding power back into the converter. Any comments?

[I_rv]

make sure you have power (shore power)to the inverter/charger and all connections are clean and tight.If the charger is bad,mine was,I got a 50 amp rv 3 stage charger from ebay for about $100.00 and just hooked it to the batt. lugs on inverter.I disconnected the 110 volts from the charger/inverter and and put a receptical in that bay plugged in the new charger and works fine and the intelec panel inside still works. good luck

[MrWizard]

?

[hostage]

map40 wrote:
I have a 36 class A that sometimes it doesn't charge the coach batteries. Even when plugged in, the batteries get low. If I jump them with the engine battery, suddenly everything is OK, even after I take the jumper out, suddenly the 12v charging system works, and the batteries start charging again. Any ideas?

It may be there is a charge relay inline that prevents feed back from the alternator to the converter ;;in line after the converter and its stuck in the alternater charge mode? don't know just a idea
OR if you have a inverter/converter combo system the inverter transfer switch may be failing; I have seen that a few times although I have never seen where jumping batterys rectified that situation

[enblethen]

It could be bad contacts in the battery disconnect!

[Sam_Spade]

MrWizard wrote:


bad connection at post or cable

THIS. Sometimes even inside the battery.

Or at the OTHER end of the main cables.

[enblethen]

The charge relay would be between the two battery systems.
The battery disconnect would be between the converter and the battery.

[MrWizard]

should Not be ANY relay between the converter and the batteries

bad connection at post or cable

converter is failing

[enblethen]

Charge relay contacts not closing or the control conductors could be corroded.
Start by checking the control voltage to insure it is getting to the studs of the relay.
Next when energized insure that the voltages on the large studs are the same when relay is energized.
This could be the same relay energized by the Aux start switch if equipped. By operating this relay manual, the control circuit could be providing higher voltage to insure closure.