Hack a Solar Garden Light Into a Flashlight

solargardenflashlight

While browsing through his local dollar store, [Taylor] came across a suspicious looking rock that, upon closer inspection, turned out to be a solar garden light. He scooped it up, took it home and cracked it open, modding it to function as a handheld solar flashlight.

Inside was a pathetically small 40mAh rechargeable battery, which he upgraded to a more standard rechargeable AA. The garden rock came pre-built with its own boost converter to kick up the voltage for the LED, but it was fairly dim. We’re guessing [Taylor] didn’t bother reverse engineering the converter and instead simply did some trial and error, but he managed to increase the LED’s brightness by slapping on a different value inductor.

As fun as it may be to have a rock for a flashlight, [Taylor] decided to cobble together a custom case out of a spare USB charger, making a battery holder and adding a pushbutton. The result is a handy solar flashlight that takes around five hours to charge. Check out some other custom lights: a lithium-powered PVC flashlight or one with a snazzier aluminum body and interchangeable heads.

Solar charging a Buddha Machine

While having ambient music playing in the background can lead to a more relaxed state of mind, we can’t imagine the annoyance of having to replace the batteries constantly. Thankfully, [Phil] added solar charging to his Buddha Machine so he won’t have to worry about batteries anymore.

If you’re not familiar, the Buddha Machine is a small plastic box that loops nine tracks of ambient music inspired the Buddhist temples of south-east Asia. There’s not much to these little boxes; they’re just a plastic box with a speaker, on/off knob and an EEPROM loaded up with samples of music.

A year or so ago, the people behind the Buddha Machine posted a prototype of a solar-powered meditative noise box that was unfortunately never made. Thankfully, [Phil Stearns] stepped in posted a guide on how to convert a AA-powered Buddha Machine to solar power.

The modification is incredibly simple: after replacing the disposable AA batteries with NiMH rechargeable, two wires are swapped connecting the battery compartment with the main PCB and the box is sealed up again. Now, whenever one of [Phil]‘s solar panels is connected to the power jack the batteries begin charging. [Phil] says he can get two days worth of runtime with a full 8-hour charge, so he shouldn’t need any batteries for his Buddha Machine anytime soon.

Makita battery pack repair

[Rob] grew tired of his Makita power tool battery packs dying so he figured out how to repair them himself. The video after the break walks us through the process which starts by cracking open the case. Inside there is a controller board and a battery of ten cells. [Rob] has pinpointed these battery failures to just the first cell, which is confirmed by measuring the cell voltages with a multimeter. The first cell in the demonstration battery reads zero volts and needs to be replaced. For some reason he’s got heck of a lot of these cells on hand, at the end of the video he shows off a massive block of them that provides one half of a kilowatt-hour of power.

To complete the resurrection he removed the control circuitry from the integrated PCB. It seems that the microcontroller on the battery’s PCB monitors it and bricks them when it thinks the life of the unit has ended. By hacking a charger he can now balance-charge the altered battery packs and get more use out of them before they hit the landfill.

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