Solar Powered Garden Lights

[silentC]

I guess the sensible place for this question is on the renovation forum, but since I don't go there....

I recently picked up a couple of boxes of those solar powered garden lights. Each of the lights has a small solar cell and a 1.5v AA rechargeable battery. There's a photovoltaic cell that is used to turn them on and off. The light source is an LED.

I've found that in the winter months, they don't really get enough sunlight to charge the batteries, so some nights they only go for a couple of hours before the batteries are flat. I don't think the tiny solar panels on each is very efficient at collecting sun light, plus being low to the ground, they are often in shadow, which shortens the exposure.

What I was thinking of doing was getting a 12v solar panel and a decent battery (I can get some 6v wet cells from my Uncle) and seeing if I can't boost it a bit.

I had a couple of ideas - one would be to run a wire in series to each light connected to the new battery and do away with the little AA cells altogether. I figure groups of 8 lights in series would be OK on a 12v circuit (two 6v batteries in series).

The other idea was to see if it's possible to get the AAs recharging off the 12v panel, which I would put up high and face north. I wasn't sure how to wire this up, but again I guess 8 in series would be the go.

Anybody got any ideas on the above?

[bsrlee]

Sounds like you are re-inventing the 12v AC lighting systems that Bunnies & KMart sell from time to time. Your main problem is going to be that DC does not like to travel very far compared to AC. I'm pretty certain that mobs like JayCar sell solar power setups that include an inverter for 12v - then you just need a rectifier per light.

[silentC]

Yeah I suppose I was just looking at the fact I got the light sources cheap and maybe there was a relatively inexpensive way of improving it. The main problem with these lights is that they need to be somewhere in open sun for the better part of the day to get enough charge, and that's not always where you want them to be.

A rectifier is bascially just a couple of diodes, so I guess not expensive. I'll do a bit of browsing on the Jaycar site. The trouble is that whenever I've looked into these things, the cost of setting them up makes them impractical.

[Buzza]

I've noticed the same thing with all of my solar garden lights this winter. You might try to have a look at the power of the batteries, as some of them are only 800, and they can go to 2500. The higher rating means better holding I think. Try Eeekbay to see how many of these 2500 batteries you can get for your dollar. This is only a suggestion, as I have not tried it, but I am thinking about trying it. Two lights I have are sealed floating balls that sit in my fish pond, so I can't dig the batteries out of them, but I bet thay are around only 800 rating.

[abitfishy]

Probably won't help you silentC as I am in NSW, but if anyone is interested in a BOX of 12 used Panasonic 6v SLA batteries (tested and charged 2 mths ago, all seem fine) for this or any other purpose, and can pickup from Sutherland, Sydney, you are welcome to them. I bought the box of them off ebay for $20 but we need to minimise stuff lying around as we are moving, and these will just sit here. PM me if you are keen.

If no takers end up viewing this thread I'll make it an official 'for sale' thread.

[silentC]

Thanks for the offer. Actually I'm in NSW too but a bit too far south to drop in and pick them up. My Uncle has his place in the mountains down in Vic running off solar power backed up by a generator. He's got a heap of old 6v cells taken from a telephone exchange which he says I can have, so I'll probably grab them and have a play around. My brother in law has a 12v solar panel too. I might see if he'll let me borrow it and set up a little experiment.

One day :)

[abitfishy]

No worries. I wasn't sure exactly where Pambula was but I knew it was too far from Sutherland for a pickup! :)

Still here for the taking.....

[mickwroth07]

I had a similar issue when i bought some cheap ones from one of those $2 shops up here in qld.

After a week or so they werent even coming on! So i decided to rip one apart and found that the batteries were useless! half of them were leaking acid as well!

So lucky enough i had a few quality AA rechargeables laying around the house.. I charged them up and whacked them in and they have been glowing bright every night ever since! (its been over 6 months, including over winter months)..

THis may be your cheapest option! Worth a try