Controller Location

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pappi49

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Sep 19, 2017
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Lexington Ky.
For those of you that have done your own solar install. I am thinking about either 2 used 280 watt panels of even one of the many 2 panel kits that are on the market. My question is where have you mounted your charge contaroller?

I realize that the closer to the battery the better. My problem as I see it is that I have a toy hauler and my storage area does not have an opening on both sides. The door to the "basement" is on the curb side and my water heater is located at the end of the compartment on the driver side. I am not certain that the controller would not be damaged by mounting it here. I realize that this would give me the shortest run of maybe 3 of 4 feet.

My second option would be under the bed but that is most of what little storage we have and half of that is already taken up by the spare. Yeah, I could move the spare but not sure it would be a good place for the controller.

My third and final option would be in the kitchen area beneath the fridege by the CO detector. This would be perfect for me based on the controller I am considering, It would also allow me to see at a glance exactly what is going on with the solar and the batteries. I would probably install a battery monitor in the same general location.

Any and all help/advice is greatly appreciated.
 

Gizmo

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Without a photo of your storage area it is hard to tell for sure. But based on your description, it sounds similar to a TT we had a few years ago. I installed the controller in the storage area by mounting it up high so any gear we stowed would not contact or interfere with the controller. You are correct to realizing the closer to the batteries you can install the controller, the better, so I would explore that option thoroughly before moving on. If after do diligence the storage area is not at all feasible, the other locations sound like doable options. If one of the secondary options ends up being the location you will want to use heavier gauge wire from the controller to the batteries, to minimize voltage drop and create more efficiency for your solar install. Also, if you have a battery monitor you need not worry about access to the controller as a battery monitor will provide all the information you need on a daily basis. Having said that, you do not want to completely bury the controller in case you do need to access it.
 

pappi49

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Sep 19, 2017
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Location
Lexington Ky.
Gizmo, can you tell me how temperature sensitive a charge controller is and if it needs alot of air flow. This may help in my determination.
 

Jayflight

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Jan 22, 2021
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276
I did not bury my controller. I was lucky to be able to mount it open within 6 feet, with my inverter in a simular distance. With the adjustable float in particular I wanted to adjust it from time to time for trickle when in storage or for maximum use when traveling off the grid. I also have the voltage read out on the face, which I can monitor my batteries. Of course I only went with group 31 deep cycle batteries, which does not give me as much reserve and the more expensive batteries.
 

House Husband

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Jan 26, 2019
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K.C.MO.
If you purchase a controller with voltage sense leads to the battery bank, voltage drop will not be an issue. The charge controller will compensate for any voltage drop. My Rouge controller is over 20 feet away from the batteries and maintains the proper charge profile voltage for my batteries.

Richard
 

Gizmo

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Gizmo, can you tell me how temperature sensitive a charge controller is and if it needs alot of air flow. This may help in my determination.
Typically 6" of airflow. As to temperature, charge controllers tend to have a wide range of acceptable temperatures.
 

Gizmo

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If you purchase a controller with voltage sense leads to the battery bank, voltage drop will not be an issue. The charge controller will compensate for any voltage drop. My Rouge controller is over 20 feet away from the batteries and maintains the proper charge profile voltage for my batteries.

Richard
This is incorrect, the leads to the battery from the controller adjust the charging algorithm for ambient temperature variations, so the batteries receive the correct voltage at given temperatures. Voltage drop from the controller to the batteries is still a consideration.
 

Lou Schneider

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This is incorrect, the leads to the battery from the controller adjust the charging algorithm for ambient temperature variations, so the batteries receive the correct voltage at given temperatures. Voltage drop from the controller to the batteries is still a consideration.
Voltage sense leads have been common on industrial power supplies for many years, and they specifically do compensate for wire loss between the supply and the controller. The way they work is the voltage sense wires don't carry any current, so there's no voltage loss from one end to the other and the controller can see what voltage is arriving at the batteries.

The trick is finding a controller with external sensing - I've yet to see one.

Don't confuse this with remote temperature sensing, where a temperature sensor located at the battery tells the controller how to adjust it's output voltage
 

House Husband

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K.C.MO.
This is incorrect, the leads to the battery from the controller adjust the charging algorithm for ambient temperature variations, so the batteries receive the correct voltage at given temperatures. Voltage drop from the controller to the batteries is still a consideration.
Wrong! My controller has VOLTAGE leads to the batteries that allow the controller to adjust for voltage drop.
What you are defining is a temperature probe.

Richard

Richard
 

John From Detroit

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Davison Michigan
For Gizmo and House...

There are charge controllers that have voltage sense leads that go to the battery. I've never seen one but I've seen the designs and even instructions for building one or rather the article is old enough I have access to the archived article.

And there are some with thermal sensors. I used to have one

And I'd not be surprised to see some with Both.
 

pappi49

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Sep 19, 2017
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Location
Lexington Ky.
Thanks for all of the suggestions but I am quite sure that even if I found a controller with voltage sense leads it would pretty much blow my budget for solar.

I have seen controllers with the temp. sense lead, so that is always a possibility.
 

Ex-Calif

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It's always disappointing to see comments challenged with posts representing alternate "facts" and no one cites a model number of a unit. Just from the outside in it is a very confrontational way to add "new" information to thread. Solar equipment evolves. New stuff comes out. Just share the info guys.

I'm generally in agreement with gizmo. and pappi49 has laid out his constraints and concerns in a clear way. I've put solar in a lot of boats. I always err on the side of airflow when positioning the controller. It should be in as clean an environment as possible, available for (very infrequent) maintenance if necessary and located near the batteries if possible.

Most owners think because it has blinking lights it needs to be mounted somewhere "readily" observable. That's not necessary, particularly with remote monitoring. I've mounted them in bilges under screw down access panels - not ideal...

Given what Pappi said so far I'd still be working the basement mount high as possible and out of the way as I can get it. Second choice would probably be the under sink option. 560W is certainly a lot of amperage potential so great caveat on wire sizing.

Not sure I picked up on the run length (total) from panels to controller to batteries in the sink location but I would definitely "have" to make the closer to the batteries location (basement) work if this turns out to be some ridiculous run of wire.
 

pappi49

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Location
Lexington Ky.
"Not sure I picked up on the run length (total) from panels to controller to batteries in the sink location but I would definitely "have" to make the closer to the batteries location (basement) work if this turns out to be some ridiculous run of wire."

The run length from the panels to the controller in this case would be about 9/10 feet and the run to the batteries would be about 17/18 feet. I am not real certain there is any place I could mount the controller that it would receice enough air flow but then I may be overthinking that part of it. By placing the controller in the basement, I would have a run of close to 25 feet from the panels to the controller.

Right now I am thinking of mounting the controller on a pc. of ply wood, mounting it to the wall of the pass thru and covering it with some type of wire mesh or grill to add protection.

It weem that there is no ideal place to put everything in order to have wire runs that seem to be of average length, but since I have never done this before I really dont know what is acceptable.
 

Ex-Calif

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In term of distance kitchen vs. basement is only a few feet and the total of 25-30 is not outside the "norms" of other decent sized power runs (like chargers to front mounted batteries in Class As)

30 feet total of solar run wouldn't scare me off. High quality hardware is key. Basement mounting plan seems reasonable.
 

Gizmo

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Apr 22, 2012
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Wherever we park it
The voltage drop you think are being compensated for is specifically to account for temperature variance and is used for lead acid batteries. A quick read of charge controller manuals will indicate this fact and often indicate the importance of wire size between the charge controller and batteries
Wrong! My controller has VOLTAGE leads to the batteries that allow the controller to adjust for voltage drop.
What you are defining is a temperature probe.

Richard

Richard
Nope! I contacted the experts at AMSolar and asked about this and here is the reply.

Bruce,
Thanks for writing. The problem with voltage drop is that it reduces the voltage. This can create insufficient charging voltage at the controller or battery, not to mention other issues. A controller will not compensate for this, the wire must be properly sized when installed.

See here for more details:

https://amsolar.com/diy-rv-solar-instructions/edvoltagedrop

Best,
Steve Bouton, Technical Sales
3555 Marcola Rd., Springfield, OR 97477
t: blocked, I can call you by appointment if you email me
e: [email protected]
w: www.amsolar.com
 

Frank B

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Apr 23, 2005
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1,409
Location
Calgary, Alberta
For those of you that have done your own solar install. I am thinking about either 2 used 280 watt panels of even one of the many 2 panel kits that are on the market. My question is where have you mounted your charge contaroller?

I realize that the closer to the battery the better. My problem as I see it is that I have a toy hauler and my storage area does not have an opening on both sides. The door to the "basement" is on the curb side and my water heater is located at the end of the compartment on the driver side. I am not certain that the controller would not be damaged by mounting it here. I realize that this would give me the shortest run of maybe 3 of 4 feet.

My second option would be under the bed but that is most of what little storage we have and half of that is already taken up by the spare. Yeah, I could move the spare but not sure it would be a good place for the controller.

My third and final option would be in the kitchen area beneath the fridege by the CO detector. This would be perfect for me based on the controller I am considering, It would also allow me to see at a glance exactly what is going on with the solar and the batteries. I would probably install a battery monitor in the same general location.

Any and all help/advice is greatly appreciated.
My older Outback FM80 controller has a fan that should keep it cool as long as there is sufficient volume of cool air to move through it. With that said my controller is mounted on a wall inside the coach, and that fan has never come on with my 6 panel 1230 Watt system feeding 6 GC-2 flooded batteries.

The only thing I regret with my installation four years ago is that I did not get a controller with Bluetooth connection to my cell phone. I think newer units can be monitored and programmed over bluetooth, which I would think would make mounting location much more flexible.
 

pappi49

Active member
Joined
Sep 19, 2017
Posts
37
Location
Lexington Ky.
I really appreciate all the help and advice you guys have supplied me with. This forum has a wealth of knowledge.

I do have another question regarding the panels. Since i will initially start out with 2 panels, what is the preferred method of wiring, series or parallel. I do know that one increases amps and the other will increase the voltage. My electrically un qualified mind says the wiring in parallel would be the way to go but I really have no idea.
 

Rob&Deryl

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Mar 27, 2017
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Location
Eastern Massachusetts
If only 2 panels, I would say series as you can use smaller wire. Though, if you plan to add more, make the wire size for the parallel config. Then when you add 2 more, make those series also and put the 2 pairs in parallel. Having a higher voltage allows the controller to work better.

Of course, if I have this wrong, I am sure someone more knowledgeable will correct me.
 

Ex-Calif

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May 15, 2020
Posts
1,432
We went to series or series parallel when we got to 4 panels or about 400W, at that point an advanced MPPT controller is also highly recommended.

2 X 100W panels was always parallel.
 

Gizmo

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Apr 22, 2012
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Location
Wherever we park it
If you plan on getting a MPPT controller, I would do a series install, because MPPT controllers like high voltage. When connecting by series the voltage doubles with a MPPT controller, which will get the most out of a MPPT controller by converting the extra voltage to amps.
 
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