How do we test our solar panels??

[Robo]

Thanks Bob.
I didn't want to just hook it up and hope for the best, being an ebay panel, & not wanting to damage vans solar equipment.
It's sort of a 2 fold thread.
I was trying to make sure I hadn't received a suspect panel, especially being a novice to solar.
and 2, another way for others to learn along the way.
cheers.

I love free camping and don't love things go wrong.
Especially with 3 women looking at ya the wrong way!!.

[the evil twin]

Thanks Bob.
I didn't want to just hook it up and hope for the best, being an ebay panel, & not wanting to damage vans solar equipment.
It's sort of a 2 fold thread.
I was trying to make sure I hadn't received a suspect panel, especially being a novice to solar.
and 2, another way for others to learn along the way.
cheers.

I love free camping and don't love things go wrong.
Especially with 3 women looking at ya the wrong way!!.

Test it the way I suggested (which is same as Vid and other links).

You can't properly test them with anything in circuit like Batteries or Regs
You have to use the Panel and only the Panel.

You have to short the Panel to see the max current.
The panel (on its own) cannot put out any more current than it's short circuit value no matter what you do
The only thing you can damage is the fuse in the Multimeter on the Amps scale if you use too low a scale.
Anything else in circuit will affect the performance and readings and may indeed let the smoke out

[Bob]

I would do what ET suggests as his knowledge is far superior to mine on this subject

[the evil twin]

I would do what ET suggests as his knowledge is far superior to mine on this subject

Sure goes against the grain to deliberately short things out eh...
Every time I do it accidently I need the fire extinguisher

You are 100% right about not doing it with a battery or other source in circuit.

[Cuppa]

I wasn’t trying to suggest that you should conduct the test with via a regulator, I was just wondering if that is what you had done & had ommitted to mention it.

If you have done as per the video & ET (& ensured the panel was shaded when making the connection ) I have no idea why your short cicuit amps would be so low unless the connection was bad or a problem with the multimeter.

[the evil twin]

Related info but possibly deserves a thread of its own...
Copied from threads on other Forums but source is from Bainbridge regarding low (poor) performance of DC DC chargers, MPPT regs and Panel Outputs.

The D250 S dual will work with a panel as low as 50 watts as we have tried it in the workshop - but as it has an MPPT inside it, the losses can be quite high with such a small panel against a PWM solar charger. PWM means - Pulse Width Modulated; and MPPT means - Maximum Power Point Tracking.

Also, with higher temperatures in Australia an MPPT on low panel outputs is not as efficient. The D250S Dual was originally designed in Sweden where it’s very much colder.

Ideally if you can go up to panel size of 300 watts it would be much better on the D250 S. The open circuit voltage on your panels needs to be no higher than 22 volts DC whatever panel wattage you use on a D250s dual.

At such low power levels, using a PWM charger will be more efficient, as you have already found out. On the other hand an MPPT charger is better than a PWM unit, when it comes to using cheaper quality panels and also obtaining the maximum POWER ( not CURRENT ) for your battery.

The following link will explain why an MPPT ( as used in the D250S dual ) is operating differently to a cheaper PWM solar charger at low power levels >

http://solarcraft.net/articles/comparin ... ntrollers/

Regards;
Kimbal Summers
Warranty Technician
Bainbridge Technologies

[Robo]

I tested it with a multi meter and struck very low amps.
Ok I'll look it up, Yep I was doing it correctly.
Well I need to confirm it, a couple of ways to get it swapped over or something.
On this site I know there's a few experts and proceed to get answers/confirmation.
@ the same time I hit the seller up for a potential DOA panel, in return get his test procedure which shows the panel is working almost to its rated capacity wtf.
Also seller tells me AS the panel is putting out 18-22 v there will be nothing wrong with it!

meters ages---analogue is + 20yrs old & digital is 6 mths old.
arhhhhhh.
didn't have time to touch it today, sunny again tomorrow, try again.

[the evil twin]

This is the scenario on a new flexible mono 100w panel.
Measuring directly with meter.
Getting good voltage sunny day 21+ volts.
But a low 1/4 of 1 amp directly to meter, yes only point 23 of a amp.

But Connect a battery inline and it jumps to over 4+ amps.
please explain.
ignore the pics 19 volts it started to cloud over, but you can get the idea.
Attachment 63323.
Attachment 63324

In the pictures... the Voltmeter is reading 18 Volts so there is no short circuit which is why the Ammeter reading is so low.
Unfortunately the pics don't show how they are connected

Did you try them one at a time?

[Robo]

In the pictures... the Voltmeter is reading 18 Volts so there is no short circuit which is why the Ammeter reading is so low.
Unfortunately the pics don't show how they are connected

Did you try them one at a time?

Yes volts then amps 1 at a time, with digital m, & struck issue.
owning 2 meters thought I'd give it a go, and was still getting same readings.
(don't think I used analogue by its self).
meter side by side picture was both connected at same time to respective posts.
being independent meters that should work!
being that each measuring different things the panel is supposed to be doing at the same time.
both connected same time was really done for the pic for seller and he never asked how or why etc.

Soon as I clear the noggen I'll be outside again, 20 yrs night shift bit slow to get going first few days of holidays.

[Cuppa]

I remain confused about the .23A but believe if the panel was putting out the expected amps when connected to the battery then it must be ok.