China takes a lot of crap on environmental grounds, and rightly so, but you do have to admire their entrepreneurial spirit when it comes to recycling, especially of electronics. One country’s trash is another country’s treasure.
It doesn’t get talked about a whole lot, but there’s a thriving industry in China that salvages and recycles electronics – and a whole other thriving industry that sells or re-uses the recovered material. Semiconductors are a popular bit of booty. Need some long-obsolete chips? Someone in China probably has a drawer full of ‘em, desoldered from junked equipment.
All those cellphone LCDs that Arduino folks and other electronics enthusiasts like to play around with? They’re not spare parts being sold by service centers – a huge number of them are recovered from broken phones.
And that, in a way, brings me to the subject of today’s post: Solar chargers.
Over the last six months or so, I’ve picked up four little solar chargers – the kind designed to charge a cellphone or iPod or whatever. In an emergency, possibly, or just because you happen to like using renewable energy. Here in the ghetto, we tend to lose power a lot in the summer, and I thought it’d be nice to have a long-term solution to keep a cellphone or two and anything else that charges via USB working following a storm.
Four chargers from three vendors, two of them domestic. Only one of the four actually worked, though. The others would charge a phone for about sixty seconds, and then abruptly die.
I thought maybe it was me. I thought maybe it was the cables. I thought maybe it was the various devices I was trying to charge.
Nope. It was the chargers. Three duds.
Curious if I could troubleshoot the problem, I cracked one open to see what was inside and how it worked.
They’re all pretty similar. Solar panel -> crude constant-voltage charging circuit -> battery -> crude boost converter -> voltage regulator to produce 5V output.
Let’s see. Work our way in from the edges, as it were. Maybe the solar panel’s a dud, and it’s not charging? Nope, it tests fine.
Maybe the output boost circuit or regulator are toast. Nope, seem to work fine.
Well, maybe the charging circuit doesn’t work. No, it’s providing 4.2 volts to the lithium battery, which is about right for a crude circuit like this.
Well, I finally figured, maybe it’s the battery. It didn’t look like the usual unencapsulated pouch cell you’d expect to find in a product like this, but, eh, maybe the factory got a good deal on an overrun or something.
Well, I pulled the battery out and peeled off the tape, and, hey, look at that…
A set of little contacts, to which wires have been soldered. It’s a cellphone battery. Probably a really old Nokia, from the dimensions and alleged capacity. You can see tape/glue residue where a label was removed, which reveals that the actual cell was manufactured by LG. So, it was a fairly nice battery, once. Around a decade ago.
Well, taking a cue from a past project, I hunted through my little stash of spare lipo batteries, and came up with a battery for an iPod mini. Some quick work with a soldering iron later, and the elderly cellphone battery was replaced.
Guess what? The charger actually works now. Crazy, huh? I made similar replacements to the other two dud chargers – another iPod Mini battery in one, and a much larger one for a (guessing here, the package wasn’t labeled) first- or second-generation full-sized iPod in the other.
Chargers like this are far from the only place that recycled batteries get used, of course. There’s a particularly aggravating industry that turns the dead laptop batteries of yesterday into the useless replacement laptop batteries of today. It’s just kind of annoying to think that there are people who have these chargers sitting around, waiting for an emergency, and are then going to get shafted when they actually need ‘em.
Morals of the story: Be wary of Chinese solar USB chargers. Also, test your emergency equipment before you have to rely on it.