Battery Issue??

[grashley]

I unplug the camper from shore power when I cut grass.  When I do, I lose ALL power in the camper, even 12V lights.  When I plug back in, all is good.  Using the battery disconnect to isolate the battery when plugged in, I get good voltage measured at the battery terminals.  Any thoughts??

 

[Alfa38User]

When you unplug, your converter ceases to produce 12V and it is no longer supplying 12V to your trailer. You will have to investigate the 12V distribution system and try to determine why the batteries alone are not supplying as expected. Starting info needed includes the make/model of converter and a wiring diagram of the system if possible. There may be relays in the converter that should be doing that.

The battery disconnect operated does not stop the converter operating (120V A/C) when plugged in, and thus you will still find that 12V (more like 13.5V) at the battery terminals. It simply disconnects the distribution of 12V to the trailer a little further down the chain. There are some items like the propane detector and perhaps, the break-away brake system that will likely still be powered as they may bypass the cutoff switch in many cases.

 

[Howard R]

Connect the batteries using the "disconnect" switch and I think you will find all DC functions, lights,etc working. (except any AC  lights if you have them.)

When you are on shore power (or generator if you have one) the AC power powers the CONVERTER, which supplies DC power for lights, control voltage for frig, water heater, ect. and charging your house batteries.  If you have a good/smart multi stage converter, such as a Progressive Dynamics 92xx, it will not overcharge or boil batteries dry if left connected all the time.

Battery disconnect switches are only needed for longer term storage.

Let us know what you find.

Howard

 

[Howard R]

I think Stu and I were typing at the same time ;D

Howard

 

[grashley]

Update:

I understand how the converter et al work.

Today, after 24 hours off shore power, the battery measured 12.6V.

The disconnect is on the battery NEG, and disconnects EVERYTHING.  It is closed.  I installed it.

I have a WFCO 8930/50 power center and a WFCO 9875 converter.

Is there another disconnect associated with the Gen Prep option I should be looking for?

 

[lynnmor]

If you have a cheap disconnect switch, check the voltage on each side of the switch with the converter running.  The cheap red key type switches are junk.

 

[Howard R]

There is often a disconnect built into the unit ... a switch usually near the entry door

Howard

 

[John From Detroit]

I also strongly suspect a FACTORY disconnect. May be marked AUX or USE/Store.

 

[kdbgoat]

If you have a cheap disconnect switch, check the voltage on each side of the switch with the converter running.  The cheap red key type switches are junk.

I agree. One came on the last trailer I had. Only worked a couple of times, then I had to bypass it.

 

[grashley]

The switch near the gen prep is an ON OFF switch, in the ON position.  When I turn off the 50A main breaker, no 12V power.  Gen Prep switch makes no difference.

My disconnect is similar to this.  Are these a problem?  Seems pretty simple.

https://smile.amazon.com/NOCO-ID220S-6V-24V-Battery-Disconnect/dp/B006EH9WUC/ref=sr_1_7?ie=UTF8&qid=1532391188&sr=8-7&keywords=battery+disconnect

 

[grashley]

To close the loop...

I went out tonite.  With power on, good voltage at battery.  Dropped the MAIN breaker, lost 12V power.  Battery voltage still good.  Opened disconnect on the battery.  Battery good when measured at terminals, no good at disconnect.  Closed disconnect.

Went inside, and did not notice the light I had on (step light) was now working.

Pulled cover off the main panel.  12.7V at top of fuse panel.  12,7V from fuse out to ground.  Turned on an interior light and all is good.  Put panel cover back on.

It seems the disconnect, though closed, was not passing power.  When I opened it and closed it, all connections were good.