project of mine: 12v panel to charge 8 aa batteries

[Sunking]

In this case....it IS however wrong to say that self regulating solar panels do not exist.

They DO

You are 100% correct. Every solar panel is self regulating because they are current sources a point which I do no think you have grasped yet. A typical 100 watt panel made for 12 volt battery systems has a Voc of 22 volts and a Isc of 7 amps.

Shell made that panel in the link above and refer to that as self regulating (and it was designed for battery charging....not just trickle charging). That is a 50 watt panel model SM50-H and it typically puts out 14.5 volts.

Kyocera make self regulating panels (model Kc35 is a 15 volt 35 watt panel.)

OK this is where you stepped into a big pile of it and where I think you do not understand what a current source is. The Shell panel you mention for example is a 50 watt panel made with 33 cells. It specifically says to be used on a 12 Volt 100 AH battery with a daily load. Please read it and explain why it is so specific

Here is your clue. A 50 watt panel with 33 cells can only generate 3 amps of current. When applied to a 100 AH battery is a C/33 charge current. If you connected that panel to a 50% discharged battery it would take roughly 5 days to fully recharge the battery assuming the battery had no load on it. That by definition as I explained earlier is a TRICKLE CHARGER. To properly charge that same 12 volt 100 AH battery would require a 160 watt panel with a MPPT charge controller, or a 220 watt panel with a PWM charge controller. To recharge that same battery at 50% would only require 1 day with a light load, not 5 painful days without a load.

Some self regulating panels are sold with a 12 volt cigarette plug to plug 12 volt things in directly to the panel (like my 5 watt panel which as I said, came with both a 12 volt cigarette plug and a set of alligator clips).

Again that is not a self regulating panel. It is just an over priced Marketing Term for a piece of junk. a 5 watt, 12 volt panel generates .3 amps. Car batteries are anywhere from 60 to 100 AH. So a .3 amp current supply is a C/200 to C/333 charge rate. There is no way in Hell that could even possible charge a car battery. A Trickle Charge is around C/100. So that 5 watt panel is not even a TINKLE CHARGER. A 50% discharged 60 AH battery would take roughly 1 month to charge up assuming the battery does not have a self discharge rate. A flooded lead acid battery has a 10%/Month Self Discharge rate. The 5 watt panel can barely keep up with the Self Discharge rate of a 60 AH battery. It is a worthless piece of crap only worth $5. How much did you pay for it?

[noone]

You are 100% correct. Every solar panel is self regulating because they are current sources a point which I do no think you have grasped yet. A typical 100 watt panel made for 12 volt battery systems has a Voc of 22 volts and a Isc of 7 amps.



OK this is where you stepped into a big pile of it and where I think you do not understand what a current source is. The Shell panel you mention for example is a 50 watt panel made with 33 cells. It specifically says to be used on a 12 Volt 100 AH battery with a daily load. Please read it and explain why it is so specific

Here is your clue. A 50 watt panel with 33 cells can only generate 3 amps of current. When applied to a 100 AH battery is a C/33 charge current. If you connected that panel to a 50% discharged battery it would take roughly 5 days to fully recharge the battery assuming the battery had no load on it. That by definition as I explained earlier is a TRICKLE CHARGER. To properly charge that same 12 volt 100 AH battery would require a 160 watt panel with a MPPT charge controller, or a 220 watt panel with a PWM charge controller. To recharge that same battery at 50% would only require 1 day with a light load, not 5 painful days without a load.


Again that is not a self regulating panel. It is just an over priced Marketing Term for a piece of junk. a 5 watt, 12 volt panel generates .3 amps. Car batteries are anywhere from 60 to 100 AH. So a .3 amp current supply is a C/200 to C/333 charge rate. There is no way in Hell that could even possible charge a car battery. A Trickle Charge is around C/100. So that 5 watt panel is not even a TINKLE CHARGER. A 50% discharged 60 AH battery would take roughly 1 month to charge up assuming the battery does not have a self discharge rate. A flooded lead acid battery has a 10%/Month Self Discharge rate. The 5 watt panel can barely keep up with the Self Discharge rate of a 60 AH battery. It is a worthless piece of crap only worth $5. How much did you pay for it?

I disagree on that Shell panel being a trickle charger...ok it is not going to do much more than that with that 100Ah battery (and yes I did read it and I KNOW they are very specific for a reason, I am not advocating using THAT panel for anything...period, it was just a link to prove the point on the terminology...if some one wants THAT panel, then follow the instructions for THAT).

Shell calls it a self regulating panel (and also refrers to trickle chargers as well), so that is good enough for me.

I would not use my 5 watt panel to charge ANY battery, not even a small AGM (I use other panels for that), for charging AA batteries though, it has been invaluable to me and in fact I consider it to be the best value thing I have EVER purchased ...and I did pay a LOT more ten years ago for it that I would today.

It is not like I am going to charge AA batteries with my 50 watt or 200 watt or what have you panels and like wise will not charge larger batteries with my 5 watt one.


Again and finally, it is just a name.....I actually think calling a panel "self regulating" as a term is a bit misleading but that IS what such panels are called.

I think I am done on this, there ARE self regulating panels, a 5 watt panel is great for charging AA batteries (not a 200000AH AGM battery) but ONLY if you are using a lower input to what you otherwise would and ONLY if you know what you are doing and at your own risk.

[noone]

Trouble ediiting

Hi
I had trouble editing so just post again.

The definition of a trickle charger

That Shell panel does a bit more than this.

http://en.wikipedia.org/wiki/Trickle_charging

The end for me on this.

[Sunking]

Again and finally, it is just a name.....I actually think calling a panel "self regulating" as a term is a bit misleading but that IS what such panels are called.

It is called Marketing to Dummies 101.

[russ]

It is called Marketing to Dummies 101.

Or maybe 'green washing 101'.

Some idiot in their office wrote that and probably had zero idea what they were writing about.

[Sunking]

Some idiot in their office wrote that and probably had zero idea what they were writing about.

They are no idiot, very clever Marketers. They come from the same school PT Barnum came from.