Solar panels age

mountainman · August 2020

How can you tell from the serial numbers on a panel when it was manufactured?
I located some 345 panels for 35 cents a watt claims they are new???
I don't have a clue on decoding but
Looks to me like it could be January 4th 2017.
Or April 3rd 2013
Or August 2nd 2014.

mountainman · August 2020

Photowhit · August 2020

You might check the model series number, 340+ panels haven't been generally manufacture until the last 5 years or so, serious doubt they are 2013...

So your

"Q plus L-g4.2 PDF says;

Image: https://us.v-cdn.net/6024911/uploads/editor/to/dv05yxrutkm2.jpg

https://d3g1qce46u5dao.cloudfront.net/data_sheet/q_plus_l_g4_2_335_345_datasheet.pdf

So January of 2017 1st revision and the panels ranged in voltage from 335-345watts.

Panels tend to get more efficient in later generations, I thin that series was 340-350 watts before it was no longer manufactured. I have an earlier series that I believe are the same form factor That are 310-330 watts. I picked them up from a commercial installer and I think that installation was in 2017 if that helps.

mountainman · August 2020

Yes thanks. So there definitely not new.
but still a good price for a ~3 year old panel with a 12 year warranty.
if they pass a voc and isc test?

wellbuilt · August 2020

I think as long as the panels are making good power now , a little age is not a problem .
I have had some 70 watt and 135 watt panels on my sale boat since 2000 .

They have been working 24/7 since then , they may of lost some power but they are still working good

mountainman · August 2020

I picked them up today they checked out great.
Only had to drive 30 miles
Round trip
much cheaper than shipping.
Now the work begins racking.

mountainman · August 2020

Is this the math to figure amp output?
2100 watts*.77/48 volts. 33 amps.

230 ahs *58volts /.77*12% 2078 array.
If I have it wrong would someone please show me the correct way.

wellbuilt · August 2020

The top is goood
the bottom 230 ah battery x 49 volts = 11270 watt hours Arty size should be 10 to 13% so 1465 watt array

BB. · August 2020

48 volt is a variable.

A very discharged battery can charge at 48 volts initially.

A battery over approximately 80% state of charge is closer to 58 volts (near or at set point).

More or less, lead acid batteries are near 100% efficient regarding AmpHour discharging and charging.

Voltage wise, charge at 58-59v volts. Discharge at 48 to 50.8 volts.

Power = voltage x current... More power to charge. Less power (energy) to discharge the same AH capacity.

Bill

mountainman · August 2020

Please excuse my lack of understanding. I have a 230 ah 48 battery. ~11kw.
I am planning to use 3s2p 6 345 watt
Panels 2070 watts.
so my array is to large for my batteries?
And just 3 panels in series 1035 for a 230ah 48 volt bank is to small?
Should I use only 4 panels 2s2p
And series parallel my batteries
For 460 ah at 24 volts?
Decisions!!! so far I've only used a 12 volt 400 watt system.
Bigger systems seem so much more complicated.

mountainman · August 2020

I have the 24 volt battery diagram.
But Is this the correct way to wire for 48 volts?

Bank?

wellbuilt · August 2020

wellbuilt · August 2020

24 volt 48 volt is really the same as 12 volt .

You need a charge controller that will handle 48 volts , and most of them can limit the amount of power they send to your battery’s so you can add extra panels that will charge better in low light .
You need to check the panel voltage 3 340watt panels have to much voltage for your controller .

I would series 8 battery for 48 volt they charge much better this way .

Real world , you start charging when The sun comes up, by 10/ 1100 am you are in absorb and your battery’s are starting to limit the power from the sun so you never really see full out put from the panels . I have 4425watts and max out at around 3750 watts but I never see that number most of the time My bulk charge ends around 1000 am and absorb starts cutting back my charging at around 1800 watts at the end of a 3 hour absorb I’m down to 300 watts or so.

wellbuilt · August 2020

BTW , I looked and your controller is good for 12/24 volts no 48 volt charging so you will need to stay at 24volt max or get a new charge controller .

mountainman · August 2020

@wellbuilt I don't understand the manual for my cheap controller says 2800 watts at 48 volts.
Photowhit also has informed me of the consequences of 3 345 panels in series.
The above 48 volt diagram of 8 6 volt batteries. 3 cables are long and 4 are short. I thought all. Cables should be the same length?

Which way is better? This certainly looks simpler.

mountainman · August 2020

Image: https://us.v-cdn.net/6024911/uploads/editor/dr/ufg5ccfs46pf.jpg

the s3-60a

mountainman · August 2020

In time when funds allow a controller that can handle 3 72 cells in series is in the works.
Correct me if I'm wrong.
230 ah at 48 volts or
460 ah at 24 would still require the same size array for 10-13% charge rate.
Are my 6 345 ~2100 watts a good match for my 11kw of batteries?
With My calculating I get 12%?

mountainman · August 2020

I have been going back over every ones posts. Thanks all
Here's my take from it.
It's hard to throw a mismatch of parts together and make it work correctly.
A Johnny cash Cadillac of sorts.

My controller panels or batteries dont match. But the price was right.

I have 2 solutions both of which involves losing the make sky blue.
1. Buy a 60 amp pwm controller with panels 2s3p
Buy a combiner and 3 50 foot runs of array wiring and breakers.

2. buy a quality mppt 60 amp controller that can take 3 345 watt panels in series. 3s2p
That will throttle back the wattage
to my smaller battery capacity.
While producing more power during
Low light situations.

Cost would be negligible
Between mppt and pwm.
With the extra components for pwm.
Combiner box and breakers. extra wire
and more complex installation.

@wellbuilt I think I finally understand
battery ah to array size.
330ah battery *49 volts =16170 watt hours *.13% 2100 watt array.

Anyone have a link to battery wiring
diagrams?

wellbuilt · August 2020

Yes the cabels should be the same size , my battery’s are wired in series like your pic above .

If you controller manual said it works for 48 volts you should be ok ?

I just took the Epever mppt30 from the equipment list and look it up , and it said 12/24 volts ?

Cheep 30 amp controllers don’t Normally go to 48 volts .

I am no expert for sure , I’m just trying to give back to the forum but , the best thing to do in my Opinion,
would be to try to get to 48 volts some how .

Then get a programmable charge controller I use out back mainly because I can call AWS and get help easily with the out back stuff from any one that pics up the phone they are very familiar with it.

@ 48 volts you can run 4000watts of solar On a fm 80 it’s easy to program with a little help .
The fm 80 and fm 60 have a 100$ price difference .

mountainman · August 2020

You are correct about the epever 30.
Its 12-24 volt only.

I have the make sky blue controller. The s3-60a.

Im guessing the epever is still in my equipment list because i haven't been able to see mine or anyones for some time now?
So I'm not able to change it.
I think something about the forum changed.

wellbuilt · August 2020

Ok , you should be ok , you need to check the voltage of the panels 345watt panels can have high voltage , 3of them in series on a cold morning can over voltage you charge controller and burn it up .

I’m assuming it gets cold There .

You need to figure this out , you may not be able to use 3 panels in series with out a expensive charge controller ,
and the voltage of 2 panels in series may not be high enough to charge a 48 volt system in warm weather .

Most charge controllers max voltage is 150 volts .

mountainman · August 2020

The manual on the charge controller claims 160 voc continuous and 190 voc limited peaks.
Not one I would have bought because
Ive read a lot of bad reviews on this cc.
If it last till mid January I'm gonna test its limits.

wellbuilt · August 2020

You should be ok with 190 peak mine only spikes for a few seconds I see a lot of -15 20 for a few weeks January February

Ralph Day · August 2020

wellbuilt said:

I think as long as the panels are making good power now , a little age is not a problem .
I have had some 70 watt and 135 watt panels on my sale boat since 2000 .
They have been working 24/7 since then , they may of lost some power but they are still working good

24/7?? I have the darndest time getting power after the sun goes down. Could you post the brand of those panels? Thanks

wellbuilt · August 2020

Very funny guy 😅

Solar panels age

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