Solar panel output

Mike Harding · Guru

Solar panel output

Peter_n_Margaret · Guru

60W is significantly more that our fridge uses, especially in cooler conditions.
Cheers,
Peter

Mike Harding · Guru

How much cooler are the conditions?

And how much is "significantly more"?

And is it a just a fridge or a fridge freezer?

And why do you think it matters?

Oh God....

yobarr · Guru

Mike Harding wrote:
Don't get carried away by hype or posts about how solar will solve all your problems, it has much merit but has limitations too:
13th May 2022, 3pm, 20km north of Kerang north western Victoria: 4 X 200W freestanding solar panels facing the sun feeding into a Victron MPPT controller producing 60W as they did yesterday and probably will tomorrow.
If I were running a compressor fridge/freezer I'd need to be running the generator.

Without wanting to get too involved in this, I would suggest that if your 800 watts of Solar are producing only 60 watts there is something wrong somewhere, particularly if the panels are facing the sun ? My Solar system NEVER needs back up and my whole van is electric, with no gas appliances. Microwave, electric frypan, slow cooker, air fryer, electric jug, TV, stereo, Diesel heater, fans, 175 litre fridge/freezer etc, AND a 2.5kw air conditioner that runs 24/7 in summer. No generator, no mains 240 charging needed, and so far, no limitations. Easy! Cheers

dorian · Guru

These guys seem to get by with minimal equipment:

https://trailersailerplace.com.au/phpBB3/viewtopic.php?t=5027

This is the fridge comparison that was mentioned in that thread:

http://www.waeco.com.au/news.asp%3Fid%3D147

Peter_n_Margaret · Guru

Just because you have a problem, don't assume that everyone else does too.
20 degrees is not a big load for a fridge/freezer.
www.bom.gov.au/climate/dwo/IDCJDW3037.latest.shtml
Cheers,
Peter

Mike Harding · Guru

Consider the concept of how heavy and extended cloud cover may affect solar panels.

Peter_n_Margaret · Guru

Mike Harding wrote:
Consider the concept of how heavy and extended cloud cover may affect solar panels.

Of course cloud cover significantly reduces solar collection, but the fridge/freezer only responds to the temperature which was quite moderate, in fact it never made 20C for the month so far.

How long have you been parked up?

Cheers,

Peter

unusedname · Member

The controller will limit the power to avoid overcharging your battery, if you connected a heavy load to your system the controller would feed more current to the system.

StewG · Senior Member

Correct. I would expect an 800W array facing the sun to produce 100 - 300W in overcast conditions with a significant load.

Dick0 · Guru

The comments above by:

Peter n Margaret, Yobarr, unusedname & StewG are my experiences of my solar system.

And quite frankly, I don't get concerned when weather is overcast and still get sufficient amp input to run any of my 240V appliances and charge batteries.

biggrin

Mike Harding · Guru

Solar panels do not have a magical component.

They can only produce a certain amount of energy and batteries can only hold a certain amount of energy.

Solar panels, charging systems and batteries may be analysed with very simple mathematics - there is no magic. Anecdotal experience is of no value.

One cannot get blood from a stone and a bucket can only hold so much water, it's as simple as that.

Dick0 · Guru

Perhaps try connecting each panel individually to test each output and if all good connect all in parallel array.

If (AGM) batteries individually are not holding 12.8V at rest then get them tested by local battery outlet.

If all above is fine then could be the solar controller. Try another MPPT or PWM controller temporarily.

TimTim · Senior Member

Visiting my son in Brisbane and found out he has a 160W Ecoflow portable solar panel/blanket so I just did a quick test on it.

Output was 143W while laid flat on the ground at 1.15 pm. There was a bit of cloud around but a good size blue sky opening at that time. So 89.3% of stated output which is pretty good considering. Price is a bit high at $449 whilst on special but at least it has decent output.

Mike Harding · Guru

TimTim wrote:
but at least it has decent output.

In Brisbane.

TimTim · Senior Member

Well I did ask if I could take it home with me and the answer was. disbelief

Mike Harding · Guru

Bloody kids! After all we've done for them... they never appreciate their parents.... :)

Jaahn · Guru

Mike Harding wrote:
Solar panels do not have a magical component.
They can only produce a certain amount of energy and batteries can only hold a certain amount of energy.
Solar panels, charging systems and batteries may be analysed with very simple mathematics - there is no magic. Anecdotal experience is of no value.
One cannot get blood from a stone and a bucket can only hold so much water, it's as simple as that.

Hmm Mike all true. But you might be able to optimise the collection of solar in the forest by this method.

My suggestion for your consideration is to get a portable light tower from the auctions. Then fit a couple of solar panels on it in place of the lights and crank it up above the trees so the panels get a good view of the sky and you can adjust the angle and direction from below too. Might be a small engineering challenge but could be an answer to your chosen location problems. Just sayin' biggrin

Jaahn

Tony LEE · Guru

If your solar system isn't living up to your expectations then either your system is poorly designed with too little panel area or battery capacity Or you are using too much power Or you are parked under trees All of which are under your direct control.

Whenarewethere · Guru

Or your wiring is rubbish & or you have bought Chinese crap.

yobarr · Guru

Whenarewethere wrote:
Or your wiring is rubbish & or you have bought Chinese crap.

Now, that's telling it the way it is! Sadly, in my years selling Top Quality Solar I saw many people buy El Cheapo panels, use El Cheapo wiring, buy El Cheapo inverters, get El Cheapo "performance" and then cry "Boo Hoo.It ain't fair".

A good quality installation will produce over 2 times as much as an El Cheapo system the same size.

Often they then decided to buy the good gear, and I used to get sadistic pleasure from advising them that there was no 2nd shot at the $5000 (or whatever it was) Government Rebate. (STCs). More "Boo Hoo. It ain't fair".

Do it once. Do it well. Cheers

Whenarewethere · Guru

That is simply laziness, should have cable tied the screw to the pin for safety!

Blues Man · Guru

Good one. biggrin biggrin biggrin biggrin biggrin biggrin

Tex260Z · Newbie

Hi guys,

Here ya go, F.W.I.W i just built another system, el cheapo 80 watt solar panel, home made 33 Ah LiFePO4 26650 cell battery pack with 20 amp Chinesium BMS, Victron MPPT regulator.

PVC frame does 45 and 86 degrees.

Tested the whole rig on my 60 litre brass monkey portable fridge at 28 degrees ambient and it all works fine.

The long and the short of it is it got the fridge part down to 6 degrees and the freezer section down to minus 8 in about 20 minutes with the panel in full sun.

The battery appeared to be holding steady all the time.

The BMS I used on my 26650 LiFePO4 battery pack is supposed to have a "balance" function, i have no specs for it so don't know if it's charge balance, passive balance or whatever. But going by the size of the cables I figure it's probably useless anyways.

Sooooo, I bought a flying capacitor active balancer for it, which was fine but I still had no idea what was going on because the orange LED on those things says on as long as it is plugged in, I only wanted to balance after a full charge, so the solution was to solder piggyback cables to the back of the balancer pins for my little ISDT device (meter only). all works a treat best result is 4 Millivolts.

I would like to add a flying capacitor active balancer to my 200 Ah LiFePO4 van system, I believe I can use an output of the BMV-412 to only activate the balancer when the cells are fully charged, so far I can't find anyone to tell me how???

Cheers

Tex

-- Edited by Tex260Z on Monday 26th of December 2022 05:08:50 PM

-- Edited by Tex260Z on Monday 26th of December 2022 05:09:34 PM

Brenda and Alan · Guru

Tex260Z Your 26650 cell are lithium polymer cells NOT LiPO4. These are the the cells that feature in fires in cars and computers among others and you would need to be very sure of your cell balancing device to be safe.

Alan

TimTim · Senior Member

Alan the 26650 size cells are also a available as LiFePO4 cells.

Tex, I had a quick look at the Victron manual and could not see where you could do that although you can set a relay for loads. I would need to do more reading on it. Have you tried to take a look at the DIY solar forum, I read a bit about making active balancers smart in there.

I purchased two of those active balancers for my two 280Ah batteries but they both gave off the magic white smoke with the typical smell . At least the seller gave me a refund smile . In the end I didnt with the balancers as I have two Daly BMSs with balancing but they do not kick in to 13.4V and until 20mV cell difference.

Tim

Aus-Kiwi · Guru

This is why I have a seperate battery so I can keep an eye on batteries charge with a little in reserve . Its a balance between having enough solar and having enough batteries to get through two or three cloudy days !! Yes never believe the hype they tell you the solar output !! Keeping fridge full I find gives some cold reserve also . Hopefully cloudy days is compensated by cooler ambient weather !! Not always !