What to do with the cells I have found?

[divemaster1963]

I came across some little solar lights for the drive way recently. they Are:

Naturelite 6volt sla solar charge lights.
40 to be exactly. got them for 5.00 each
I found the batteries dryed up from setting up for 20+ years.
I re hydrated most of the batteries and are using 12 to light the drive. nice low light effect.
I have two hooked to a 12 volt valve solenoid for my solar heater for the pool. comes on a 8 esh off at dusk. want to heat not cool the pool.

Now what to do with the rest. I have tested a panel and get about 5,8 to 6,2 volts out. amp meter not working so not sure of the amps.

these little panels are 6x6 inch. each is sealed with 2 leads coming out. positive and negative.

now the big question.

what would be the best arrangement to get good output with amps to boost my little 45watt hf setup to help charge my 6 12volt setup in my shop?

any suggestions would be helpful  and appreciated.
thanks john

[oztules]

So you have some 26 left to play with...


My best guess is that you will see about 6w from each panel  ie approx 1amp.
If you connect three in series you should see perhaps 16v@about 1amp.
If you make up 8 parallel strings of three (24 used up now), you may get 8Amps into your 12v battery bank on a good day will depend on charge condition.... a bit more if you have mppt perhaps.
 and the last two as spares for something else.


............oztules

edit...the 6w mentioned above is obviously wrong, perhaps closer to 3 and if amorphous then less..... maybe 4A into the batteries on a good day.... oz

[divemaster1963]

Great.
I was think about the same but wanted a second motion.

3 by 8  I have a 60 amp charge controller that I gotten awhile back at a steal for future use. guest I get to use it now.

thanks oztules.

I get to play with making panels with a short cut of not having to seal and solder . every dog gets a bone now and then.

I'll get some photos up as soon as I can.

[ghurd]

Were they in a black metal box, amorphous PV at a 45 degree angle, light bulb in the bottom, shipped from an optics place out of NY?

Mine made more volts than that.  Maybe check them in better sun with no fingers over the front?

Seems like maybe 100~200ma?  Been a while since I looked at them.

G-

[oztules]

Yes Ghurd,

I have a 6x6 that makes about 22v,open, and 300ma short..... so it is about 5-6w at it's power point I suspect. They used a circuit board as a base, stuck on the myriad of tiny cells, and sealed the lot with EVA. Just checked it in the sun a few minutes ago out of curiosity.
It was used in a small electric fencing unit.


............oztules

EDIT:

Gee I'm sorry Ghurd and John, I decided to play with it some more... it just didn't feel right..... with a different meter.... not good news divemaster..... looks more like 3watts now....(<200ma) then used a shunt and measured that......still much poorer than I thought. Ghurd is closer to the money than I was.

Use a small known resistor and take a quick measurment of V lost over it and use ohms law to figure the current .. I=E/R.... then we won't have to guess any more.

Interesting a new 6x6 cell can do 8amps/.5v or 4W.... how I could possibly think we were going to get 6w from the same size.... I'm not sure.

Must stop plugging the meter into voltage sources (48v battery bank) while still plugged into the amp range.... the internal shunt may have suffered more damage than I thought after the last stuff up.

So if yours are about 3w, then you will look forward to .5A... not 1

Thanks for the wake up Ghurd

[divemaster1963]

Were they in a black metal box, amorphous PV at a 45 degree angle, light bulb in the bottom, shipped from an optics place out of NY?

Mine made more volts than that.  Maybe check them in better sun with no fingers over the front?

Seems like maybe 100~200ma?  Been a while since I looked at them.

G-

The ones I found were in plastic molded boxes with the panel on the top and the 6 volt bulb facing at a 45 to the panel .
has a small curcit board with a light sensor and on/off switch.
the SLA's are Malfree GP1.2-6 
6volt at 1.2 ah.

I am still going to try different scenarios to see what output I can get.
Been to cold to get outside for any good time to play with them

[divemaster1963]

Were they in a black metal box, amorphous PV at a 45 degree angle, light bulb in the bottom, shipped from an optics place out of NY?

Mine made more volts than that.  Maybe check them in better sun with no fingers over the front?

Seems like maybe 100~200ma?  Been a while since I looked at them.

G-

Hey Ghurd and oztules
I got a chance sunday to check them out in a beautiful day ( 72 and sun sun sun )
I got 11.5 volts open with .5 amps . I repaired my meter and got 8 volts .92 amps into a 6 volt sla with a starting voltage of 5.8.
how does this sound .    Do you all think it would still work for a 3 x8 setup. hooked  with my HF 45 watt setup.

let me know.

John.

[ghurd]

how does this sound . 

That sounds far better than mine... and I would have bought more if mine did that!

But a couple of the numbers are a bit screwy.

Short circuit current is 0.5A?  Current into an 8V battery is 0.92A?  That's not right.  Short circuit current is higher than current into a battery.

Also, 0.92A at 8V is an awful lot of power from a 6x6 panel (I do not believe it).  I expect there is an error in the 0.92A reading.
That would be 32W per square foot.  The HF panels make about 5W per square foot.

Most/many of the 6V panels in old yard lights make about 9V open.
The 11.5V open means 2 in series will be fine for 12V.  Would need to try it with a couple pairs and a decent 12V battery to be certain.

Guessing they are Not amorphous?  Maybe they have 18 or 20 individual crystalline cells?
G-

[divemaster1963]

I thought that it was wrong. I need to toss that meter and get a new one. I'll try and get better readings this weekend. here is a drawing of the panel. ( if I can get it to load).

[ghurd]

That is amorphous, same as the HF type PVs.
I'd expect maybe 1.1 to 1.4W?  Maybe 150ma.

Before you toss the meter, try installing a new alkaline 9V battery.

If you are someplace warm, strong sunlight can change the reading on an inexpensive meter.  Maybe try to keep the meter shaded behind a cardboard box.

G-

[divemaster1963]

thanks for the support for the meter. I'll try that out with the box. As soon as I can I am going to hook up a panel of these to see what I can get out of them. then I going to look into oztules fun project we did. I was trying to figure a way to not miss up a bunch of used cells. ( we just got a solar plant two counties over that just opened. I am going to try and go by and see what they do with chipped cells ) maybe I can get them at a steal. the company is Magna out of Europe.

thanks again
john

[tecker]

Ni cads are fairly cheap if the ones in the system are dried up  . I find a 50 volt pulse is integral to a battery system .Chain them together and deliver a pulse charge to your bank of batteries as dump .