should my inverter (7amp) have a 7amp charge controller?

[tidewater4ten09]

I wonder if I could run it uninterrupted with a setup like that also wondering what type of battery setup (deep cycle marine 12v or 2 6v golf carts) would like it to be somewhat portable because it's basically for entertainment/minor backup. thanks again.

Edirors note:

Not much info to go on here, but its a slow Saturday so we will toss this in see if anyone can help dig out enough info to give you an answer you can use.

[henjulfox]

Charge controller is a function of the solar panel, not the inverter. What is the

output of the panel? Frankly, if it's one of those battery maintainers, it's not

worth your while to buy a battery or charge controller to match the panel.

Batteries are heavy, making portability difficult. What kind of loads for what

period of time do you want to run?

-Henry

[K3CZ]

Battery charging functions and load functions are entirely separate.  Size your charge controller (and anything more than a couple of charging amps does call for a charge controller) to cover the max amp capacity of your panels, now or in the future.  Your inverter load can be anything you desire or need, depending only on battery capacity for the timeline.

As far as battery capacity is concerned, certainly the sealed AGM cells are less prone to problemes with tipping over, etc.  Otherwise, anything of  the deepcycle type that you can carry will work fine, with golf cart and lift truck batteries lasting longer than Walmart "Marine" deep cycle batteries.  Good luck - should work FB.

                                               Van   K3CZ,   PE

[tidewater4ten09]

hey thanks for the response; by saying tiny panel I mean tiny it's a uni-solar us-5 with a whopping 5 watts max power,current max power .30a,voltage max power 16.5v  they're website says something about it being designed for 12v applications I wonder what it would take (how long in full sun) to damage/overcharge a battery? these pieces of 'equipment' are just things I have laying around the house I'm just a beginner/hobbyist. eventually when I own some land it will be completely off-grid so I'm trying to get an idea of the basics. thanks for listening

[finnsawyer]

One thing you can do is get your terminology straight.  there is no such thing as "current max power" or "voltage max power" only max(imum) current (amps) or max(imum) voltage (volts).  Power always and only refers to watts (joules/second).  You could refer to the current and voltage out at maximum power, but that's a different animal.

At five watts output it is not likely you could overcharge the battery unless it's very small.

[nothing to lose]

Well looking at what you are doing, 5watt pannel, 800watt inverter, I would say forget the controller myself. Connect it and check manually.

At 5watts It's gonna take 160 hours of solar power to run the inverter 1 hour at full 800watts. So figure from that

What are you gonna run on it? 100watt light bulb 1 hour = 20hrs solar charging at 5watts. Gonna get how many hours a day charging, 5? 4 days to replace 1 hour of power for a light bulb.

Now figure in about self discharge of batteries, inverter and wire loses etc..

 Ok even if you use a 15watt CFL bulb, it still takes over 3 hours of good sun to power the light 1 hour a night, not figuring the loses.

As long as you are going to be using more that your making you don't really need a controller. And for hobby stuff I would watch it manually when using it, go by that.

Should be fun, but I dought you could ever hurt a battery with the pannel if you ever use the inverter. More likely any battery damage would come from draining the battery to low durring use, not from over charging it.

[tidewater4ten09]

   well thanks once again for for the knowledge the terminology didn't make sense to me either but I did type it word for word off the back of the panel.  Happy trails.

[finnsawyer]

I guess they did mean the voltage and current at maximum power.  Were there hyphens or some other punctuation mark after current and voltage?  That would imply they meant the values for maximum output.

[ghurd]

Most brands list amps and volts as 'at' maximum power, open volts, and short circuit amps. 0.3A x 16.5V = 5W rated, or 0.3A x 13.5V = 4W real output under great conditions.

The panel is very small and will barely keep up with self discharge of a larger battery.

G-