No power to rig when generator turns off...

[thefid]

93 Holiday Rambler Class A

Symptom: Everything including DC turns off when generator turns off.

Batteries have 9.5v and therefore dead.

See attached images...

Power coming in to these (relays?) is 13v, the output is 9.5.

My questions have to do with can these be reset or should they be replaced? All four 5amp fuses test good for continuity.

If replace, what modern setup will work?

Thanks in advance for your help.

 

[uchu]

You are right. Batteries are dead. How old are they? Is the generator your only power source?

If on shore power, the batteries should be getting charged via converter.

 

[thefid]

Batteries are Lithium and only a couple years old. Power is not getting to the batteries because of the relays in the attached images will only output 9.5v.

 

[phil-t]

Not a professional but this is what I would do -- Disconnect batteries from coach; Connect an external battery charger good for lithium and see if they will recover, then look at why your system will not charge the batteries. output on the relays - you are likely reading battery voltage?

 

[DonTom]

Power is not getting to the batteries because of the relays in the attached images will only output 9.5v.

How much voltage is on the input relay contact? The relay shouldn't have any noticeable voltage drop when closed, even under load.

-Don- Reno, NV

 

[A Traveler]

A relay is nothing more than a switch. It’s either on and passing current, or it’s off and not passing current.

If you’ve got 13 volts in and 9 volts out, either the relay is bad, or the connections to it are dirty and corroded. Relays rarely fail, so clean the connections first.

 

[RNS]

I would guess if you have 13 in and 9.5 "out" which is what you have on batt the relay is not closing

 

[Contributor]

If relay is bad, bypass it and see if the batteries take a charge. Maybe the batteries are so discharged they are in their Lithium sleep mode.

 

[DonTom]

If relay is bad, bypass it and see if the batteries take a charge. Maybe the batteries are so discharged they are in their Lithium sleep mode.

I find relays in RVs to be very reliable. I have yet to see one fail. But I would check the input contact voltage and if that's okay, I would check the relay coil voltage. Perhaps it isn't being keyed on when it should be.

BTW, I see in that photo that those cables on the relay could use some cleaning.

-Don- Reno, NV

 

[John From Detroit]

Ok so when the generator is running the converter is providing power for the 12 volt systems
At 9 volts and change the batteries are either 1: In serious need of replacement (likely true)
2: NOT connected and thus not charging (Also possible)
Suggestion
Measure voltage at battery terminals (most positive to most negative) with generator running and power on
Same voltage as generator off... Disconnected.. Check disonnect. fuses and breakers (Main 30 amp fuses breaker could be larger)
13. or more.. Batteries need replacement. If MARINE/deep cycle. they WILL most likely need replacement no matter what.> GC-2 might recover.

 

[thefid]

A relay is nothing more than a switch. It’s either on and passing current, or it’s off and not passing current.

If you’ve got 13 volts in and 9 volts out, either the relay is bad, or the connections to it are dirty and corroded. Relays rarely fail, so clean the connections first.

Thanks for the tip, that is what i was looking for... I cleaned the contacts and still have 13 in and 9.5 out. I am assuming the next cheapest potential fix is replacing all four of the fuses.

I did find a replacement relay online if new fuses don't work.

 

[DonTom]

I cleaned the contacts and still have 13 in and 9.5 out.

Are you sure the relay coil is energized? Perhaps that 9.5V is coming back from the batteries or whatever and the relay is not even engaged.

BTW, is that a latching relay? That means it requires power to close and needs power again to open.

-Don- Reno, NV

 

[RNS]

This is the manual for the relay.

relay

 

[Ernie n Tara]

Measure the Voltage at the relay output with the battery disconnected from it. Zero V means the relay is not energized. Check further.

Ernie

 

[Contributor]

My questions have to do with can these be reset or should they be replaced? All four 5amp fuses test good for continuity.

If replace, what modern setup will work?

You can just buy new relays on Amazon or other places. This is the cheapest I found.

01-00055-000 Intellitec Battery Disconnect Relay

01-00055-000 Intellitec Battery Disconnect Relay

www.pacificrvmirrors.com

One thing to note is that these relays are latching relays. They use momentary voltage and ground to open and close. Once in either position, even if you remove the control voltage they stay there, until being commanded other wise.

two inputs to control the relays are "S" and "I".

"I" "S"
Close 12VDC GND
Open GND 12VDC

Seems that you have another relay below that seems to be in parallel and controlled by the same signals.

Since these are latching relays, once activated, the control signals are likely removed. So even if you measure the control signals "S" and "I" you will not see any voltage. If you try to activate the relay and you use a voltmeter you may not catch it, depends on the length of the signal.

It's possible that the control signals are not working and the last operated state was in the "open" condition. So since these are latching, the relay is latched there until it gets proper commands.

One way to test the relay(s) close function is to take a 12 VDC battery with two wires and connect the negative post to the "S" terminal, then momentarily touch the plus 12V to the "I". This should close the relay if it is good.

 

[Kirk]

Measure the Voltage at the relay output with the battery disconnected from it. Zero V means the relay is not energized. Check further.

Ernie

Or the relay coil is energized but it has failed and the contacts either didn't close or are damage beyond use.

 

[Contributor]

from the manufacturer.

" While this relay is capable of carrying heavy currents, it requires NO power to stay open or closed. It only draws power during activation"

 

[Kirk]

It only draws power during activation"

Which means that it is a latching relay with a coil to close it and a different one to open it. Even so, the contacts can become burned to the point of failure or they might fail to latch. That is verifiable with a volt meter if you lift the battery side it should see the voltage of the supply if closed. If it does not, there is a failure.

 

[Contributor]

Single coil and a magnet keep it latched.

This design is to prevent constant current drain from the battery supplying the control voltage.

THE RELAY - How It Works
The Battery Disconnect Relay is a mechanically latching switch that operates by the momentary application of battery voltage to the coil terminals in one direction for latching (closed) or the other direction for unlatching (open).

To close the relay, +12 volts is applied to the "I"' terminal and ground to the "S" terminal of the relay. When this is done, the plunger is pulled into the coil and the contacts are connected. While this happens, the rod magnet suspended above the plunger is attracted (opposite poles attract) to the top of the plunger by the magnetic field.

When the voltage is removed from the coil, the plunger gets pushed upward by the return spring, but cannot move because the rod magnet is in the way.

 

[Gary RV_Wizard]

It is clear the disconnect relay has not closed, since a closed relay would show the same voltage on each side. So the question is why is the relay open? Either the "close' function has not been activated (voltage applied to the primary) or the closing coil is not working. The latter is conceivable but low probablility; it's a highly reliable device. Not rocket science, so some straight-forward problem determination ought to determine which it is quite quickly. Verify that whatever circuit activates the primary coil is actually doing so, or manually trigger the primary by applying 12v from another source. Then test the secondary for continuity (zero ohms) across its terminals.