Charge Controller Installation location

Hi Jonny and BFL13,

About 1/4 of all the energy used for charging a lead acid battery is dissipated as heat. That raises the core temperature of the battery. Similarly, on discharge, the internal resistance of the battery causes the core to rise in temperature.

Every chart and all the data provided by battery makers is correct--at 25 C (77 f). As soon as the internal temperature deviates from that number, the charging voltage should be "tweaked" to have the most efficient charging possible.

The charge controller needs to be placed where it will not get wet, not where it might not get wet. If it will be where the sun can shine on the compartment it will happily reduce the charging voltage unless the battery temperature sensor is used.

I know I have a lot more important things to think about than a battery temp sensor. But getting back to location, every controller display I have ever seen was mounted on the side panel as you enter the doorway, which can be seen standing outside w/ the door open, or standing inside. Thats where I mounted mine also. Hard to believe anyone would mount them in some places like has been mentioned on this forum, namely under any cover, closet, or any other out of sight place. And I don't care how far it is to the batteries, its location first, then you deal w/ distance to batts, which people make way too bigga deal of that too. But to each his own I guess.

Jonnygsx wrote:

westend wrote:
Mounting options:

Carlon 8" x 4" Weatherproof box

Irrigation timer box (you can probably source just the enclosure at a local irrigation shop).

If you have an electrical salvage store near you (most major metro areas have a few), they will have a variety of enclosures for cheap. I bought a 14" x 18" NEMA rated enclosure with a clear polycarbonate lid and lock hasp for less than $10. It houses cable TV and Sat TV junctions in my sticks and bricks.

Now were getting somewhere westend! Great idea here, but the charger says that it gets very hot and to place it somewhere it won't be bumped cause it can cause burns.... this was a concern I had for mounting it inside while also close to the batteries hard to find a safe location. Do you think putting it in this box would be an issue with poor air circulation or melting of the box/fire hazard?

The plastic or spun fiber boxes are pretty durable. Don't know what you have for a charge controller but mine gets barely warm, I have it indoors in a cabinet. I guess a guy could leave a couple of knockouts/box entrances open for ventilation. If you have fears of fire, get an exterior friendly metal box, they are even cheaper.
Does your controller have an encapsulated circuit board?

Solar charge controllers can be sensitive to heating- mine are for sure. They need air cooling. They have internal temp comp which means the unit has to be in the same ambient as the batts. Some controllers get warm if run at max amps for a time.

IMO just keep it in out of the rain, out of the sun, and not in a small box where it will not get enough cooling air. Mine go in the front cargo bay of the 5er which is near the batts and has good ventilation.

The user's manual will be clear on installation so it gets air cooling. Do what it says.

I can see it/them in there if I ever want to look at the display information on the units. I don't need them inside, because I have the Trimetric inside where I can see that. Mine don't have remote displays.

Ha funny I didnt even think to look at the manual for mounting instructions, was going to use it more for setting up the dials and switches. Anyways the manual says to mount it in a waterproof box if it might be exposed to water. Doesn't say anything about ensuring ventilation so i'm not going to worry about it. Thanks for all the advice everyone!