Solar Panels - Information and Questions

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Ctxkid..I thought I would get 13 amps from a 250 watt Panel..What do you think ..Might need 4 panels..to get 40 amps..
 
Jaros..Not quite ..These panels actually put out between 18 and 21 volts ..250 divided by 21= 11.9 amps.. Thats what Ive been told..Cheers..
 
Baldy said:
Ctxkid..I thought I would get 13 amps from a 250 watt Panel..What do you think ..Might need 4 panels..to get 40 amps..
i have 250 watt mono's that average just over 9 in full sun , i don't know why they rate panels in watts they don't deliver
 
ctxkid said:
Baldy said:
Ctxkid..I thought I would get 13 amps from a 250 watt Panel..What do you think ..Might need 4 panels..to get 40 amps..
i have 250 watt mono's that average just over 9 in full sun , i don't know why they rate panels in watts they don't deliver
i also have 120w blankets that make 8amps , my watt meters are the tell all , i might do some vids at work comparing and showing the figures
 
1547860259_p1120571.jpg

1547860259_p1120573.jpg
 
ctxkid said:
Baldy said:
Ctxkid..I thought I would get 13 amps from a 250 watt Panel..What do you think ..Might need 4 panels..to get 40 amps..
i have 250 watt mono's that average just over 9 in full sun , i don't know why they rate panels in watts they don't deliver
That is the max possible with full radiation at the perfect angle when they are cool.

Get two panels, leave one in the sun and one inside an air con house.
Test the amps on the hot panel, then pull out the cool one and quickly wack it on the same test bed and you'll see a significant difference.

They have to state the max possible so the system can be calculated for max possible power, but the panel rarely does that.
On my system, the eastern panels almost produce full possible amps in the early morning on a cool day, when they heat up a bit that slowly tapers off.
The panels on the western side never have that cool advantage and never perform as well as the eastern side.
 
Ok people, For once and for all, You will only get full wattage (amps) out of a panel when the batterie is almost completely empty (12.05Volt) 50% discharge.
Or you have a fridge working it's a$$ off while charging a batterie.
Fridge off and batterie charged almost fully, and the panel won't and can't deliver more watts/amps then the batterie can absorb.
So in full sun tilted just right, a panel can deliver almost full wattage when there is a empty batterie or lots of power draw and almost nothing when there is no power draw and the batterie is full.
Easy to test this yourself by switching the fridge on and then off and look for the current from the panel.
Just my two cents (and yes i have tested it this way myself). :Y:
 
The test I've seen done by the Elec Engr I bought my panels from, was a pair of old car headlights in parallel pulling over 10 amps. The battery was full, the panel was a 110W (the portable concertina I have) In bright sun it was delivering just over 7 amps. After about 15 minutes in the hot sun it was still delivering 7 amps, so minimal drop off.

So, headlights connected to battery via alligator clips, panel connected the same way. So long as the current of the load is more than the expected current of the panel, the panel will be working as well as it can. As my Engel only pulls 3 amps and most portable 12v fridges not much more, they are not the ideal test load. Loads were measured with a very accurate (and expensive) clamp ammeter. The important thing is that I witnessed the tests. Dropping a battery i.e. an AGM to almost flat to test solar panels can be expensive as it does not do the battery any good. Neither is using a much heavier load on a new battery i.e. a 2000W inverter loaded up. So if you want to test 400W of panel a load of 30 amps should be enough.

The test on the panel that blew my mind was; he then put the panel inside the workshop a couple of metres in absolute shade and it was still delivering a charge of over 1 amp, coming inside from radiated UV. (the roller door was up)
As I've mentioned in another thread, most panels out there work from visible light, so more light = more output, less light = less output. The cells on these panels are also sensitive to UV & IR so they work well in cloudy overcast conditions and much better than the average panel at the beginning and end of the day. It and the two on my van roof were not cheap, but they work as advertised. Set and forget :)
 
My son has a 120 regulated solar panel connected to a 57 amp hour aux battery. When he is driving the voltage meter is showing 15.2 volts in the aux battery and 14.2 in the start battery. Is this going to be harmful to the aux. the solar is permenantly fixed to the aux battery. Thanks for any help
 
the solar panel should not be connected directly to battery, but thru a PVM or MPPT charge controller. Some panels have a regulator/controller built in, usually the smaller 'trickle charge' types.
15.2V sounds a bit too high! usually 14.8V max charge voltage for an AGM
 
kemjak57 said:
My son has a 120 regulated solar panel connected to a 57 amp hour aux battery. When he is driving the voltage meter is showing 15.2 volts in the aux battery and 14.2 in the start battery. Is this going to be harmful to the aux. the solar is permenantly fixed to the aux battery. Thanks for any help
 
Redfin said:
kemjak57 said:
My son has a 120 regulated solar panel connected to a 57 amp hour aux battery. When he is driving the voltage meter is showing 15.2volts in the aux battery and 14.2 in the start battery. Is this going to be harmful to the aux. the solar is permenantly fixed to the aux battery. Thanks for any help

yep Redfin, I seen the 'regulated' bit, but I was more pointing out to kemjak57 the 15.2volts ..... its a bit high. I would be checking that 'regulated' panel ..
 
My "Box of tricks" has evolved from the SD2100 days (first photo) through, GPX4000, GPX4500 too 2019, umpteenth upgrade completed today (second photo), a new era and new detectors. Everything tucked in together on the back of the ute. (third photo) Charge Garmin Rinos, SDC2300 ("C" cells & 18650's), GPZ7000, 40 amp battery charger, 600 Watt Inverter, Ctek smart charger, socket to run Engels (39 & 80 Litre) Samsung Mobile charger, 12V water pump supply.. The 110AH deepcycle battery under the tray is charged by alternator while travelling, solar on roof through PVM regulator and when parked up detecting a 120W foldable solar wired in series through a MPPT regulator is plugged into Anderson plug. This set up has been a blessing, no forgotten lost, tangled leads, everything runs through it's own fuse. All we need now is some cooler weather.





 
hey Nightjar, what is the 4 digit meter with the ring of UFO whirly LEDs around it. Assuming its a volt or amp meter, but whats the go with the circle of LEDs?? Looks like an LED compass or RF direction finder but im a bit stumped!
 
Ded Driver said:
hey Nightjar, what is the 4 digit meter with the ring of UFO whirly LEDs around it. Assuming its a volt or amp meter, but whats the go with the circle of LEDs?? Looks like an LED compass or RF direction finder but im a bit stumped!

Wrong on all accounts DD, it is a USB powered DIY Digital clock, temperature and date. Enjoy fiddling and this little project was cheap and an interesting, was more than happy when I powered it up and it worked.
Similar one here, but not the actual, does not post to Australia.
https://www.ebay.com/itm/C51-DIY-Li...D-Clock-Production-Suite-Kit-SP-/263721226133

Damn pity your comment was deleted ctxkid I'm a fan of constructive criticism. Stick to your leggo! :p
 
Nightjar said:
[Damn pity your comment was deleted ctxkid I'm a fan of constructive criticism. Stick to your leggo! :p

it went something like "looks like a birds nest" ;)

[img=...]https://sh-s7-live-s.legocdn.com/is/image/LEGOMKTG/email-subscription-thank-you--gl--201606[/img]
 

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