Solar prep?

[bdreinv]

Originally Posted by Bigmike1461

Why don't I want to have inverter and controller in same compartment as batteries?? In my trailer I have plenty of space for all.

In our fiver its real easy to keep an eye on whats happening with charge controller being in the hall!Been there all most two years seems to be working fine.

[rsday75]

Originally Posted by Bigmike1461

Why don't I want to have inverter and controller in same compartment as batteries?? In my trailer I have plenty of space for all.

You don't want anything in the battery compartment that could spark. It would be a rare occurrence, but safety first.
Also, the gases the batteries can produce can corrode the electronics in the charge controller.

[WarrenG]

Originally Posted by rsday75

Just keep in mind that the location marked for the charge controller isn't likely the best location. You want the charge controller very close to the batteries. I used there prep for my install, but mounted the controller in the storage area 3ish feet from the batteries.
The wire run form the panels to the controller can be longer as voltage is higher.

I disagree. I like having the controller on the wall where I can keep an eye on what's going on and the state of battery charge. From what I've seen with my system is the number of amps from the solar panels to the controller is only ~ 100w/14.5v = ~ 7 amps-usually less than 5 amps each.

From the controller to the batteries the amps can't be more than that. I have 5 panels and a 40amp controller (you never get more than ~ 90w from a panel). The 6 (or 8 for fewer panels) awg wires can handle that for the short distance to wherever you want to put the inverter and batteries. You might want larger cable between batteries, and from batteries to an inverter-depending on its size.

I throw the breaker in the main box that allows the inverter to run properly while I have a cord plugged into the inverter and the entrance to my shore power. This way the whole trailer (lights, satellite TV, etc. runs as if I have shore power, except we don't use the microwave and the fridge is on gas.

Here's a chart: https://www.westmarine.com/WestAdvis...e-And-Ampacity

[rsday75]

Originally Posted by WarrenG

I disagree. I like having the controller on the wall where I can keep an eye on what's going on and the state of battery charge. From what I've seen with my system is the number of amps from the solar panels to the controller is only ~ 100w/14.5v = ~ 7 amps-usually less than 5 amps each.

From the controller to the batteries the amps can't be more than that. I have 5 panels and a 40amp controller (you never get more than ~ 90w from a panel). The 6 (or 8 for fewer panels) awg wires can handle that for the short distance to wherever you want to put the inverter and batteries. You might want larger cable between batteries, and from batteries to an inverter-depending on its size.

I throw the breaker in the main box that allows the inverter to run properly while I have a cord plugged into the inverter and the entrance to my shore power. This way the whole trailer (lights, satellite TV, etc. runs as if I have shore power, except we don't use the microwave and the fridge is on gas.

Here's a chart: https://www.westmarine.com/WestAdvis...e-And-Ampacity

It isn't a matter of the wire carrying the amps, it is all about current drop.
First off, will a charge controller work mounted further from the batteries, yes. Will it work as good as it can? No.

Batteries need a very specific voltage range during charging. I will use flooded lead/acid and 3 stage charging for my example.

During Bulk charging, you want 14.4 volts, Absorption 13.7, and float at 13.2.
If you mount the charge controller too far from the batteries, you could easily lose .2-.3 volts. Thus the batteries will not be getting the optimal charge, nor recharge as quickly as is possible.

Again, it will work, just not as well as it could. This is why the very high dollar charge controllers have remote monitoring or displays. You mount them close, and have the display where convenient.

Dropping even volt or two from the panels to the controller while not optimal in not nearly as detrimental to the whole charging process.

[WarrenG]

There's no such thing as "current drop". You probably meant voltage drop. The chart is very conservative because it's not based on the ability to carry amps without melting the insulation, it's based on not having a voltage drop of more than 3 or 4%. The voltage drop with a proper wire size will be less than half a volt over 20 feet, and less if you use a larger wire. This is easy to measure. A decent controller, like the one I bought for about $40 allows the user to set the battery type so the voltage and current are optimal for the battery. With all of the variability within a solar system during a typical day a few tenths of a volt really doesn't matter.

As it is, my controller only has to run near full charge for a few hours or so in the morning before the batteries are about full, and since I don't really use them all that much until late afternoon and evening, everything is fully-charged long before then, even if it does take an extra 15 minutes because of a tiny voltage drop from the controller to the batteries.