"Boondocking"

Sharon_is_SAM

If you have factory installed solar, the battery switch will not isolate it.  Ditto for an inverter.  Otherwise, the battery switch turned to off isolates the battery from all loads in the TaB.

SolidCamper

Thanks Sam. I don't have any solar- but when you say inverter? - you don't mean the converter that is part of the trailer 120/12v system/charging system  as it is shipped, right?

Excuse my ignorance, but I'm assuming that an inverter that you mentioned would be a separate item, paid for as an add-on, connecting to the battery when there is no shore power and someone wants 120vAC- yes?

Bottom line, if I only have the base setup with a converter under the driver side bench, with no solar or inverter, I'm safe to disconnect the battery and charge it on shore power AC running thru the trailer?  

Sharon_is_SAM

Inverter for a 320 would be after market - used to run 110 appliances via your battery.
Converter is the standard power center.

So, correct, no installed solar or inverter, you can charge the battery using the appropriate charger plugged into a TaB 120V  outlet while on shorepower with the battery switch turned off.  

renesadae

Aloha e all,

Along this discussion, we are back to picking up where we left off - trying to get from 'Newbies' to 'Slightly Used Boondockers'. Gotta rewire our gray-haired brains now along with our (real:) 2022 320CS factory installed solar and standard battery (we will switch to Lithium eventually) for some gear to help us stay in power. Checking in...

In PNW, Canada, Spring, Fall, Winter boondocking will these 4 purchases get us 2-4 days with judicious energy use?



Victron MTTP 75/15

Questions:
1. Would these connect to the SAE connector on the tub putting the Victron solar controller in the box wired to the battery?

2. Do we need to reverse the polarity with the adapter to keep polarity of wires the same to the SAE connector on the tub?

3. What wire gauge do we need to use when we wire the solar controller in the tub?

4. We would like to be able to efficiently view the full system. Is that just an option in the Victron phone app? We have the app and use it for the 320CS panel already.

pthomas745

The solar panel setup you have listed is a "suitcase", which comes with a solar controller. Are you expecting to buy a separate Victron controller to use with the "additional" portable solar? 

The current Victron setup in the trailer will monitor your battery voltage, etc, even with the extra panel. 

If you are going to use the suitcase (with its necessary controller) it probably comes with MC4 connectors dangling off of it.  An MC 4 to SAE cable would be needed from the suitcase to the SAE connector on the trailer.

And: a multimeter will show you whether or not you need the little "adapter" to make sure you get the wires straight to the SAE port on the trailer.  These cables are just cranked out with little thought about how or why an SAE port on the trailer works. The only way to guarantee you what "pole" of the SAE plug at the end of the cable is "hot" and what is the "negative" is to use a multimeter and test it.  Test, test, test. 

The SAE port is wired so that the "positive" (hot) cable from the panel needs to be the wire that is encased "in plastic",  not the wire that has the bare metal end.  Ignore cable colors.  Multimeter it and know.  That is the only way to guarantee when you need to use the "adapter."

Sharon_is_SAM

You will be able to network the new Victron controller with your installed Victron controller via VictronConnect.
We use portable solar and we do not use the SAE port on the tub as we find it to be a fragile connection.  Rather, we have pigtails that come off the controller and the battery to allow us to use more secure MC4 connections.
If you have a shunted battery monitor, you may want to connect the negative battery lead at the junction box.
To use the SAE and SAE adapter at the tub as you plan, you will need MC4 to MC4 extension - not the SAE to SAE extension.
Regarding polarity, with whatever connections you make, you need to make sure the positive and negative leads aline to the positive and negative terminals at the battery.  An easy way may involve simply switching the SAE leads at the battery terminal.  

You can use 12 gauge wire to connect the controller to the battery.  I think the wires coming off the SAE are 12 gauge already.

qhumberd

pthomas745 said:

The solar panel setup you have listed is a "suitcase", which comes with a solar controller. Are you expecting to buy a separate Victron controller to use with the "additional" portable solar? 

The current Victron setup in the trailer will monitor your battery voltage, etc, even with the extra panel. 

If you are going to use the suitcase (with its necessary controller) it probably comes with MC4 connectors dangling off of it.  An MC 4 to SAE cable would be needed from the suitcase to the SAE connector on the trailer.

And: a multimeter will show you whether or not you need the little "adapter" to make sure you get the wires straight to the SAE port on the trailer.  These cables are just cranked out with little thought about how or why an SAE port on the trailer works. The only way to guarantee you what "pole" of the SAE plug at the end of the cable is "hot" and what is the "negative" is to use a multimeter and test it.  Test, test, test. 

The SAE port is wired so that the "positive" (hot) cable from the panel needs to be the wire that is encased "in plastic",  not the wire that has the bare metal end.  Ignore cable colors.  Multimeter it and know.  That is the only way to guarantee when you need to use the "adapter."

Being an electrical novice, I was trying to follow this advice with my Renogy 100W suitcase which comes with a controller (my TAB@400 has an SAE port put in by dealer but no solar). When the suitcase is opened and not connected the controller shows an error and no voltage is output that I can read on my meter. But it works fine when I plug it in. I had to trace the pos and neg wires from the suitcase, which are marked, to the trailer and then work thru the MC4 to SAE adapter which output the Pos to the uncovered lead. That was wrong so a second short adapter SAE to SAE switched it to the Pos output on the covered lead and that worked fine. But It would not read voltage until hooked up. Safety reason from the solar controller?

pthomas745

A solar controller needs power from the battery to operate and start to show voltage, etc.  I might have to go out and look this morning, but I "think"  I can read the voltage from the panels with a meter on the cables from the controller, without them connected to the trailer.  I'll go out and play with this later.

Denny16

You will get a voltage reading directly from the solar panels.  The controller, however needs to be connected to a battery to work.  The controller gets its power from the battery connection, not the solar panel connection.  
 Cheers 

qhumberd

In my case the solar controller with my suitcase panels clearly turns "on" when I put it in the sun, but shows a screen error. Checking voltage between the positive and negative MC4 connectors shows nothing at that point so I assume the controller is not letting current flow from panels to output until it senses the battery voltage?

Denny16

Correct, most solar controllers need the battery in the circuit to work correctly.  The controller can be a duo-powered unit, getting some power from the solar panels, and battery, but it needs a battery load to determine the amount of charge to send to the battery. A charged battery will then power the controller, and it will stop charging the battery.  No battery, no charging voltage, think of the controller as a gate or valve, sending charging current to the battery when needed and shutting it off when not needed.
 Cheers 

qhumberd

Very helpful. So the advice to use a meter to check the polarity/voltage of the output of the controller to the trailer will not work then if I understand all this. There should be polarity indicated at the output of the controller to the MC4 connectors that you will have to trace to whatever connector you are using for the connection to your battery; then use your meter to confirm the polarity/voltage of the connection on the trailer side (in my case an SAE plug) before you actually connect. Since most modern controllers have a reverse voltage protection built in, you would likely not damage anything if you did it wrong.

pthomas745

Even my cheapo controllers have given me an indication that a solar panel is correctly connected, even if it is just a light.  The controller I have now, an Epever 20amp Mppt, apparently will display what it might "need" to send to the battery, (depending on the settings) even if a battery is not connected.  The picture is of the meter connected to the leads of the SAE cable "Out" to the battery.) Top photo indicates the "proper" outputs to the SAE port (big metal part "inside" the plastic". Bottom shows the "wrong" way, indicated by the negative number of the reading.  Apparently, this controller has some type of power control that uses voltage  from the solar panel to create a readout on the display.  (You can see it in the background).  My settings are for "lithium" so the 14.5V would be the "approximate" settings for my battery.  I'll see if I can get my ancient Renogy controller hooked up later and see what I might get out of it.

pthomas745

Here is my ancient 2014 solar controller with some cobbled together cables.  The pic shows the controller simply passes through the output of the solar panel.  (The cables are a bit of a clown show, but they are wired correctly!)