10A controller capacity

[dependencies]

Unable to find anyone on net experiencing this annoying problem with my solar set-up so thought I'd bother you guys instead of lurking here further:

Been using a 40W panel which came complete with 10A controller,
then added (as I happened to have) a smaller 20W panel, connecting it in parallel using the 'y' adaptor set I bought, isolated the panels during this with a switch before the controller
but control panel blanked out, no sign of life at all,
hmm,
unplug the smaller panel revert to the 40W alone & all is well again.

Thinking it might be some form of mismatch between panels i put idea aside for awhile,
some months later I ordered a 60W panel from same supplier so they would be same construction etc, plugged this in alongside the 40, but controller again goes blank again,

so where am I going wrong please

Richard

 

[762X39]

I am not an expert in solar but have you tried the 60 or the 20 watt panel by itself with the controller to make sure it's not something dumb like polarity? In theory, your system can handle over a 100 watts. Also refer to this link for info on mixing panels. http://solar.calfinder.com/magazine/mixing-matching-solar-panels

 

[dependencies]

Odd thing this I think, but yes tried variation of all three panels now, all work independently of one another,
but not in any combination,

switch only interrupts the positive cable and only there because somewhere I read you should never just 'plug in' a panel,
they all came with their plugs on, the connectors are idiot proof
plus as I say any one panel works fine

 

[dependencies]

OK on a different tack,

If i pair up the new panels to make 100W, tested their output with a multimeter and got 12V+
That would suggest the controller was either faulty/insufficent capacity,

So either just buy a bigger one say 20A,
Or,


do i actually need a regulator for a 100W setup ?

 

[doug720]

Typically, all solar set ups need a controller. Most solar panels have high voltage outputs that can damage equipment and batteries of not limited.

"Smart" controllers are available that optimize the panels output for charging. We have this on our motorhome and it works great. Our system is larger, 4 pairs of 6 volt batteries and 7 panels, so limiting and controlling the output is critical. Our system is 10 tears old and works great.

Doug

 

[dwh]

OK on a different tack,

If i pair up the new panels to make 100W, tested their output with a multimeter and got 12V+
That would suggest the controller was either faulty/insufficent capacity,

So either just buy a bigger one say 20A,
Or,


do i actually need a regulator for a 100W setup ?

If you didn't have a battery connected to load down the panels when you tested them, then 12v ain't nearly enough.

A proper "12v nominal" solar setup should be capable of putting out at least 15v to the battery when under load (i.e., charging the battery).

Check the voltage ratings of all the panels that you rigged together. Numbers such as Vmp (that's the voltage they can produce under load) and Voc (no load) should be fairly close if you want them to work together - say within 10% of each other should be close enough.

And yea, you need a controller of some sort. Any solar setup powerful enough to charge a battery is powerful enough to overcharge it. The controller prevents overcharging.