Wiring solar controller directly to electronics

[concretebox]

I purchased the Renogy 100w solar kit, it came with this controller (http://www.amazon.com/Renogy-Contro...6436&sr=8-1&keywords=renogy+charge+controller).

This controller has an option to wire something directly to the controller, by-passing the battery (I think it was meant for lights?). Right now I just have the controller wired to the battery. Would there be a significant advantage to running a connection from the controller to my 12v power supply or to the invertor or one dedicated 12v outlet?

My understanding is the power flows from the panel to the controller to the battery and from there to the 12 volt systems and my invertor. I also imagine on a sunny day the battery is charged as quickly as I discharge it from normal use. Am I wrong? I'm trying to take full advantage of my solar system.

 

[1977dodge]

I purchased the Renogy 100w solar kit, it came with this controller (http://www.amazon.com/Renogy-Contro...6436&sr=8-1&keywords=renogy+charge+controller).

This controller has an option to wire something directly to the controller, by-passing the battery (I think it was meant for lights?). Right now I just have the controller wired to the battery. Would there be a significant advantage to running a connection from the controller to my 12v power supply or to the invertor or one dedicated 12v outlet?

My understanding is the power flows from the panel to the controller to the battery and from there to the 12 volt systems and my invertor. I also imagine on a sunny day the battery is charged as quickly as I discharge it from normal use. Am I wrong? I'm trying to take full advantage of my solar system.

I have that exact kit one thing i can tell you is unless you are in a very sunny area the PWM controller that comes with that kit is marginal for charging your starting battery here in overcast WA it took nearly 3 weeks to get a decent charge back in the battery as my commute is short but now involves using headlights with an MPPT controller it is measureably better I also installed a Battery Condition Meter that shows the state of charge and i also monitor my battery with a Hydrometer
hope that helps
Roy

 

[concretebox]

Roy, I appreciate the help, but your response seems completely unrelated to my question. I'll restate in case I wasn't clear: Can I/Should I run wires from the controller to a power outlet in addition to running wires to charge the house battery?

 

[Bela's Mom]

I have the same controller. The manual recommends that you only attach a small light to the load output. I have my inverter attached directly to my battery.

Bob has recommended the Blue Sea fuse box from Amazon. I tried to cut and paste the link for you but I couldn't seem to get it. They have several with different amounts of circuits. Since it is best not to have too many things attached directly to the battery, this box allows you to attach various 12 volt items to the box, then wire the box to the battery. You could wire some 12 volt outlets to it for your electronics if you don't want to go through your inverter.

If you go to Amazon through the link on this forum, Bob will make a bit from it.

Hope this helps.

 

[Bela's Mom]

As far as your second question about your battery being charged as quickly as it's discharged, you need to figure out the amount of power you are using during normal use. Your panel is only rated at so many watts/amps under optimal conditions. If you are using all it can output, your battery is getting nothing.

You might want to add up the watts each appliance uses. I convert that to amps X #of hours used. You also need to know how many amp hours your battery is rated; only use 50%. Then you can get some idea of what you can use and, with continued sun, still keep your battery topped up.

When I am boondocking, I allow my battery to charge until it is in float before I start charging up electronics or using anything else. I want to make sure that I have a full battery come evening. I only have 140 watts of solar so I have to keep track of all that I use.

I'm sure others who are more experienced will chime in.

 

[akrvbob]

The first thing to remember is that if you hook anything up directly to the controller, it will only have power when the suns up high enough. Do you have anything that would work for? Most things we want to work all the time or at night.

No, don't hook anything directly to the controller.

A 100 watt panel isn't a lot of power and during the winter it is even less, during a winter storm it might be very little--or even nothing!!

In the summer it you might be swimming in power, but that can all change very quickl!!!

The key to a small solar panel is to learn power conservation!! Use as little as you can and have a Plan B!

Bob

 

[1977dodge]

Roy, I appreciate the help, but your response seems completely unrelated to my question. I'll restate in case I wasn't clear: Can I/Should I run wires from the controller to a power outlet in addition to running wires to charge the house battery?

apologies for not giving the answer you were looikng for as mentioned the Renogy 100 watt panel is a good panel but it just will not power very much
without leaving you in a debit situation on your battery
as Bob said dont use the load side of the controller
I just have mine hooked up to the Battery to assist the alternator in keeping the battery topped up
Roy

 

[Bela's Mom]

This particular controller allows you to attach a small light to it and set it to come on at dusk or night. I don't use it because I don't want a light on all night. I can use a lantern if I need one.

Concretebox, I found the link and Bob's instructions on installing the fuse box...here it is. http://www.cheaprvliving.com/blog/category/electrical/

But like Bob said, 100 watts of solar is not much so I would definitely figure out how much power your electronics use and how many amp hours your battery is rated for before you start plugging in a lot of stuff. Another option is a generator to charge your battery when you don't have enough sun.

Just as an example, I was on the coast last week. Full sunshine every day, however, the moisture in the atmosphere in the morning kept me from even getting to bulk charging voltage until about 10 am. Full sun doesn't always mean full charging!

There sure is a learning curve to this.

 

[concretebox]

Thanks for the tips guys and gals. I understand now.

 

[Optimistic Paranoid]

I believe the "load" hookup is used in stationary settings to wring every last drop of power possible from the sun. When the battery is fully charged, instead of cutting back, the excess power is diverted to a load like a heating element in a water heater.

The load hookup allows you to do this without overcharging your battery bank.

In mobile settings, the "load" hookup is just ignored.

Regards
John

 

[highdesertranger]

when I bought my panels the guy told me not to even use those load terminals, he said to run everything to the batteries. the power available though the load terminals is pretty miniscule anyway. highdesertranger

 

[66788]

when I bought my panels the guy told me not to even use those load terminals, he said to run everything to the batteries. the power available though the load terminals is pretty miniscule anyway. highdesertranger

I think it is intended to be for lighting and the reason it's on the controller is so that the Low Voltage Disconnect (LVD) can cut off the load should the battery drop to a predetermined voltage to prevent damage to the battery.

 

[anm]

I purchased the Renogy 100w solar kit, it came with this controller (http://www.amazon.com/Renogy-Contro...6436&sr=8-1&keywords=renogy+charge+controller).

This controller has an option to wire something directly to the controller, by-passing the battery (I think it was meant for lights?). Right now I just have the controller wired to the battery. Would there be a significant advantage to running a connection from the controller to my 12v power supply or to the invertor or one dedicated 12v outlet?

My understanding is the power flows from the panel to the controller to the battery and from there to the 12 volt systems and my invertor. I also imagine on a sunny day the battery is charged as quickly as I discharge it from normal use. Am I wrong? I'm trying to take full advantage of my solar system.

The PWM charge controller that Renogy supplies works just fine contrary to what some people believe. Sure you can throw more money at your system and get some very marginal improvement but a 100 watt panel is never going to put out anything more than ~100 watts.

And about the 'load' terminals:

Contrary to what people think, the 'load' can be used for connecting your loads to the system, but you will be limited current-wise to the 30 amp rating of the Renogy charge controller, it will shut down if there are over-loads. The PWM charge controller is designed so it can be used at remote sites for controlling some electrical apparatus that needs to be switched on on some 24 hour schedule (such as lights), but if you set the on time to 24 hours, it's on all the time, and it will handle up to 30 amps. I've never had mine anywhere near that. But after saying all that, for us, there really is no need to connect to the 'load' terminals on the PWM controller, just do what most people do and connect loads to the house batteries (through appropriate fuses of course).

Where it does make sense to connect to the 'load' terminals is when using the View Star PWM charge controllers. You are still limited to the charge controller's ampere rating (10 amperes on the smallest to 60 amperes on the largest) but the charge controller can tally charge/discharge statistics by keeping track of kilowatt hours into and out of the house battery -- you can see what you're putting into the battery and what you're taking out. If you decide to not use the View Star's 'load' terminals then you lose that functionality, at least the discharge statistics. The VSxxxxBN series of View Star charge controllers also allow 'all' battery charging parameters to be changed including voltage levels and time to charge at the various levels. Battery charging specifications are not all the same, some manufacturers recommend different charging voltages etc, with the ...BN charge controllers you can tailor them to your battery.