I finally got my butt in gear to test the solar chargers I’ve had for I don’t even know how long. Yesterday, Saturday, February 16, 2014 was forecast to be a seriously gorgeous day, and I had several additional chores to which to attend. It seemed logical then that I spend the time in the kitchen and checking periodically out the back door.
As a refresher, the smaller unit is designed primarily as a battery charger, but can also charge a cell phone so long as batteries are also installed. I have yet to determine a brand name and can only find them at Amazon by search for “solar battery charger”. At a price of $20, it’s not easy to pass up. Originally, I didn’t pass them up because at that price, even if it didn’t work, it would not be a catastrophic loss.
The biggest drawback is that I use a mini-lantern that was available (I haven’t seen them for the past month) for $5 each. It’s relatively simple to drain the batteries in a lantern. These lanterns run on 4 AAA batteries. The solar charger can charge 4 AA or 2 AAA at a time. I don’t know why it’s designed so, but that’s why I have two.
I loaded both chargers with the batteries from a lamp I had been draining for two days. I placed them on the porch at about 8am and made sure they were as perpendicular to the sun as possible. I know that solar panel efficiency is reduced if not aimed directly. (There is another technology that is less sensitive. More on that later.) Every couple of hours I would check the angle of the shadow behind the chargers. If it had become slanted to one side, the east, I would rotate them so their shadow was cast slightly to the west. By 5pm, the sun had dipped behind the hills to our west and the chargers were now well in shadow.
On the bottom of the unit, where the batteries are loaded, there are three LEDs which will indicate charging status when the button, also on the bottom, is pressed. Once back in the house, where the sun was less blinding, I pressed the button and received a “green” status. I was highly encouraged! Since I have worked with electronic technology for over 40 years, I know that batteries, no matter what type, are notoriously difficult to accurately test. For instance, if using a voltmeter, even a nearly dead battery can read out at its rated voltage. A load is required for accurate testing. Or, since I still have AC power, I chose to use my AC charger, made by Rayovac. It has a pair of countdown to charge timers. The initial indication was approximately 45 minutes, and it took somewhat less than that for the display to read zero time left to full charge.
We’re not exactly back to maximum daylight exposure, so I was quite pleased with the results. These mini-lanterns are the greatest for reading lights, but they do provide a more than adequate area light. If left on a side table or desk, they can actually be somewhat annoying. The LEDs shine upward into a conical reflector. If the LEDs are below eye level, they are quite intense. Not fun at all! However, by elevating them somewhat, for instance, a plant hook in the ceiling or the top of a bookcase, the light intensity is reduced and quite comforting.
The Suntactics sCharger-12 (now sCharger14) is advertised to not only charge a tablet device (iPad, Galaxy Tab2 7”, etc.) but allow it to run while charging. It can charge two such devices at the same time. Or two cell phones, or a cell phone and a tablet. As long as the device can be charged via USB interface, the sCharger-12 can handle it. It also has an “Auto-Retry Technology”, meaning if the sun is temporarily blocked, charging will automatically resume, which apparently other devices cannot do without a manual reset. Well, those are the claims.
Because I had the sCharger on the top step and needed to adjust the battery chargers, I can confirm the “Auto-Retry”. Having my Galaxy Tab2 7” connected, every time I blocked the panel with my body and then cleared it, I could heard the tablet reconnect to the charging source. I must admit, I hadn’t thought about the restart tech because I was used to the loose wall connection for my tablet! Nice to know it works!
Generally, electronic devices don’t like heat. Suntactics recommends that whatever device is being charged be protected from direct sunlight. As a solar panel likes to be as perpendicular as possible to the sun, I simply propped the panel with the tablet. You can see the tablet charging cable coming from beneath the panel. Knowing the panel uses mono-crystalline technology, I didn’t shift it for maximum alignment. Mono-crystalline is the most efficient, at this time, and also the most expensive.
No shifting, no checking the status. I should probably have checked more often. I plugged the tablet in at 57% charge. I wanted to at least test the pair. I thought I had read that the panel would charge a tablet in about two hours, but I don’t see that on the site now. However, just shy of the two hour mark I checked the charge on the tablet. Simply turn it on and the charge status display is at the top. 100%. I’m hoping that I can try it again when the battery is considerably lower.
Sitting beneath the panel on a day of full sun all day, the tablet, also in its rather sturdy sleeve, had only increased in temperature by a few degrees. Maybe ten. The panel is made of a very sturdy material, which may additionally act as an insulator. I’ll have to repeat this test in the summer. That will provide two tests. We have our monsoon season in August, when it’s also about the hottest here. I’ll need to protect the tablet, but I think that won’t be difficult.
Next test will be to charge both my phone and tablet together from the Suntactics. I’ll also test the battery charger with 4 AA. Just have to get them discharged.
Overall, I consider the tests a grand success!