How can I tell if the converter is charging chassis & coach batteries?

[lost00]

  I just finished install new Battery cable and battery Isolator and 1 starter battery and 1 deep cycle battery

and everything work good. so when i plug outside wall and i am not sure if our power converter does charger
on classic and coach battery? and how do i know if it work or not ?  and does Power Coverter auto charger prevent
over charger battery?? 

76 Winnebago Custom

[1990HR]

I just did this today to see if my converter was working and to see if it charged the starter battery as well as the house batteries while on shore power.
The best way is to test the amperage going in and out the battery. I use a shunt to protect my multimeter as I can start the vehicle while checking amps to see the starter draw as well if I want.
Hook your multimeter to the negative post of the battery to test amps. One lead connect to the battery's negative post the other lead connect to the negative cable.
Remember, the current is going through your meter if you do not use a shunt so read what the maximum current your meter can handle or you will blow a fuse or worst on the meter.
First: Have your house batteries isolated if you have that option. You should read 0 amps.
Second: Turn on the house batteries. With a light on or two you should read a small amount of negative amp draw (current being drawn from the battery)
Third: Plug into shore power. You now should have a positive amp reading (current going into the battery)

You can do this to test your starting battery also to make sure it is getting charged off shore power or making sure your alternator is charging the batteries. Also for checking circuits that are shorted and drawing your battery down when everything is off.

To find a circuit that is killing your battery, check for an amp draw and then start pulling fuses.
Pull a fuse, no difference, put fuse back, go to next fuse.
When you pull a fuse and the meter goes from a negative draw to 0 you find the problem circuit.

Hope this helps.

[jeno]

on mine it says in the book the inverter does not charge the starter battery, but yours may be different

[PwrWgnWalt]

Hi Lost;

First, Jeno is talking about an "INverter"... I know of exactly NONE that that charge batteries (they INvert 12vDC to 120 vAC power).

Second, your questions revolve around a "CONverter" - these CONvert 120 vAC into 12 vDC power. 
If (and this is a big IF) your converter is original to your '76 Winnebago, it probably adds a moderate, continuous unregulated charge to the chassis battery whenever you are plugged in to shore power.  The easiest way to know is a direct read-out of some sort - for quick testing, a voltmeter applied to the chassis battery should show it is charging.  For a permanent monitoring device, there are many out there, and without knowing what your MH is equipped with, it is hard to offer advice.

It is possible that your MH has had its converter changed at some point, too.  The modern converters are usually 3 or 4 stage units, which regulate the charging to be kind to your batteries.

- Walt

[DaveVA78Chieftain]

To answer your charging question properly I need to know what model (brand/model) Power center you have.  Most likely a Progressive Dynamics power center but there are different models each with different specs however most that year had a 6 amp regulated charger board.

Dave

[lemortede]

I have spent way too much time researching this and other questions about what the general/standard set up is. I have spent alot of time monitoring the voltage and amps under different situations. While it varies by year the general setup is as follows:
Chassis positive and the cable to the starter attach to one side of the isolator switch. You may also have one additional set of wires that's labeled as accessory. This makes up the chassis side. On the other side of the isolator switch you will have another set of wires that will connect to the coach electrical and the power center and a wire that jumps to the disconnect relay. You may also have your generator starter cable connected to this terminal. More commonly it's attached to the  disconnect switch along with the jumper wire. Finally on the other side of the disconnect switch you will have the battery for the coach.
Hopefully that all made sence.
Now your original question, typically the coach will not charge the chassis battery. This is because the isolator is not on and so is segragating the chassis from the coach. From what I have read you do not want to turn the isolator relay to dual to enable the charging of the chassis battey while you are connected to shore power. Note that if you disconnect your coach battery with the disconnect switch the coach battery won't charge either.
From what I have read and observed you can safely charge the coach batteries off the chassis alternator while you are on the highway provided you enable the isolator to dual and ddon't have the disconnect switch disconnected.

[DaveVA78Chieftain]

Hmm, 76 model year does not have disconnect solenoid.  Only cross connect solenoid.

[lemortede]

Then unless you enable the cross solonoid I would guess that your coach won't charge the chassis.btw, you might consider getting a disconnect solonoid. They are not much but make it easier to store your rv.

[Bnova]

  I just finished install new Battery cable and battery Isolator and 1 starter battery and 1 deep cycle battery

and everything work good. so when i plug outside wall and i am not sure if our power converter does charger
on classic and coach battery? and how do i know if it work or not ?  and does Power Coverter auto charger prevent
over charger battery?? 

76 Winnebago Custom

As everyone has already mentioned, it's hard to know for sure without knowing what your Make/Model your power center is.  My MH is 10 years new than yours, a Chevy Chassis and it has a Parallax Power Control Center.  This unit has a battery charger and also a battery disconnect solenoid that is energized when shore power is plugged into or the Gen is running.  It takes the coach battery off line and puts it on the charger.  Then the converter supplies 12v to all the dc powered stuff in the coach while the battery is getting charged.

On mine, I can tell whats going on by putting a voltmeter to the blue wire on the (power control center) which is converter 12v power out to the coach devices.  Then I can put voltmeter on green wire which is going to the coach battery and would see it is being charged.  These two voltages would be different, you can see on mine the voltage from the converter dropping as you continue to turn on more lights etc. and this is normal. 

I can also check my coach battery level and chassis battery level on the monitor panel as well.  In addition, I can hear the battery disconnect solenoid in my power control center being energized when I start the Gen or plug into shore power.