Having alternative energy as one of my hobbies, I've recycled an old bedside cabinet to be used as a solarpowered energy-backup. This project is low-budget and most of the materials are recycled.
At the moment it is only solar charged using 3 12 Volt 1,5 Watt trickle charger solarpanels (no charge controller needed), but I hope to upgrade it to solar and wind power with a charge controller. The key here is just that I've not found a sutable schematic yet to build a charge controller. Sugestions are welcome...

Step 1: Solar setup

This is the set-up of the solar panels. I've fixed them to an old drying rack which is hanging on the balcony of my condo. Three of the panels are connected to the cabinet, one is trickle charging a separate battery. Despite the fact that my balcony is facing east, the yield is enough to charge the battery which is used to charge my cellphone or play the built-in carradio.

Thanks for the worries, Mitchiko. But each of the panels has a diode build-in, so overcharging or discharging is no issue. Daniel Deacon, this setup is part hobby, part experiment and part almost daily in use nowadays. So an extra battery is not for nothing.
<p>right I've got one</p>
There is also a potential of overcharging and self discharge of the battery. I recommend that you add up blocking diode, zener diode and all those stuffs that will help protect your battery dude.
I agree. Without a charge controller (even a simple $20 one from amazon) you run the risk of overcharging. Diodes (the full name is blocking diodes) allow power to only go one way (from the panel to the battery). It doesn't have a limit on voltage, and therefore its too easy to overcharge them. Plus, since these are sealed lead acid batteries, any overcharging would result in obsessive gassing and the eventual death of the batteries.
These batterys are abit of an overkill if you ask me
<br> No charge controller needed?<br> <br> A SOLAR trickle charger, puts out a minimum of 15V+ and 1 - 2 W.<br> <br> Run them as a gang, in parallel, especially into a SMALL battery, and&nbsp; it's no longer trickle charging, or flotation charging a VERY LARGE 12V battery;<br> <br> It's kind of slow surge &quot;boiling&quot; the small battery.<br> <br> Yeah I did read the instructions... 2 chargers for one battery and 1 for another battery.<br> <br> <br> Might be better to run all the solar chargers and the batteries in parallel.<br> <br> With my limited knowledge of electronics, a charge controller for say 13V battery with a 5W charger, should be able to be done with a comparator style circuit using a biased transistor, a trim pot, a few resistors and a few diodes.<br> <br> A $2 job.<br> <br> Run your batteries until they reach ~11V, then leaving everything switch off, test them with a multimeter every half hour on a sunny day, from morning till late afternoon.<br> <br> How and where the sun is located and how the cells are lit will be a very important thing as far as input charge goes... but you need to do two things, measure your PEAK charging current and seperately - your peak battery voltage and then chart the differences.<br> <br> When the battery reaches it's peak surface voltage, then you need to stop the flow of current to it.<br> <br> Read up on transistors, and their switching capacities and their on / off voltages, and then rig up a resistor and a trim pot to control or fine tune the switching voltage.<br>
Very nice. I'd be very interested in the schematics. This would come in very handy during emergencies when standard electrical, cable, and telephone lines are down. I like the slipper space, but I'd personally put a stash of glowsticks, emergency candles and lighters/matches, or cheap garden solar lights there.
i agree my old house would lose utility serves about once a month so we had a rechargeable battery with a cb radio (we didn't have cell phones yet) and car stereo plugged in to it but with new car stereos you could have everything down to your tv on it

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