Solar panel /bat combo

[wildbill hickup]

The solar panel (36 watt 12vX3a) I have puts out 18V max open in brite sun. The bat pack is 19.2 v 1600 ma NiCd. Will the lesser voltage of the SP keep the bats from over chargeing. Will the bat pack just come up to the max output of the panel (or am I way off base here?) The load is going to be LEDS that I can pretty much set up the way I want say matched with a resistor for 15v (this I can adjust). Will this cause to much of a load on the panel or just not charge the bats?

[wildbill hickup]

OOPs always proof before posting the voltage on the LED's was 18 not 15. Sorry

[drdongle]

An 18 V panel will NOT charge or keep charged a 19,2 V battery. I recon you need a panel putting out about 24 V for this battery. Or change to a 12 V battery (simpler).

[pyrocasto]

You'll probably have to get another panel and series them or something. Just have to get the voltage over 20 volts

[hvirtane]

You can also use a voltage booster

to rise the voltage from your

solar array to charge the batteries.

I don't know, which kind of boosters

there are available in your place,

but maybe somebody else can recommend.

- Hannu  

[wildbill hickup]

Nuf said,I guess I'll just gave to rewire bat pack for 12v (pretty easy to do), wishfull thinking on my part, but that would make it to easy. :-> Thanks guys

[Bruce S]

Wildbill;

   Good to see those NiCds are working for you.

If you're using a 12vdc PV then try using a simple diode & cap DC-DC voltage doubler setup.

The PV is small enough that you shouldn't have any over charging problems.

The doubled voltage will be fine I've seen these take 22vdc on a deep cycle and still be just fine, your current is still low enough to keep them from getting hot and the diodes should give you enough voltage drop to come down to a useable voltage.

 I can't make use of this, as I drain the NiCds too far down and it'd take mine a week to just charge on set let alone 20.

What was your up time on that pack?

Bruce S