Though
slightly off topic, I thought some of you might find this $10 gizmo as great an idea as I do. If you have a bunch of 18650 batteries sitting around because you jumped on the "CH" sales that have been posted here (as I did), how about a little plastic case that holds four of them, and gives you two USB ports that will supply 2 Amps each to charge all your phones and tablets and whatever else you have that can be charged from a USB power source. It will even allow you to charge the 18650s using a USB power supply (like the one with a mini connector you already have for your phone).
Clicking on either picture will take you to the web site I found this on, and using the coupon code "TENOFF" will get you a 5% discount (hey, I don't make up the code names). Shipping is free. It also comes in a version without the little "State Of Charge" battery indicator, in either white or pink, for 50¢ more (again, don't ask me, I didn't decide to charge more for the version that has less).
I just ordered one, but since I haven't seen or used it before, I don't know if it's a piece of crap or China's latest gift to mankind. When i get mine, i'll report back.
[Some Caveats, One Really Important]
From the look in the pictures, the negative connection on all the battery slots is in parallel, so if the positive connections are also in parallel, you'll have to be
really careful to put similarly charged versions of the same brand and type battery in there.
Putting a dead battery in along with three charged batteries will be a recipe for disaster if the four battery compartments are all just wired in parallel! Looking more closely at the pictures, it appears that the two left hand negative connections are one piece of metal, as are the right two right ones, and they're connected together with a piece of wire soldered to the adjacent springs. I can't really tell much about the positive connectors from the pictures.
Also, I don't know if this case requires four batteries to work at all, or if it will work just fine with one, two, or three in there. It may be that each pair of batteries will drive one of the two USB output ports; or not. Edit: I just read some reviews on the web site, and it apparently works just fine with any number of batteries, including just one. It also apparently has a built in LED flashlight, and the switch on the side turns the flashlight on and off. The main power switch is on the top...
[/Some Caveats, One Really Important]
Still, it's only $10 and change to find out, so that's what I've done. I'll report back after it arrives. It would be really nice if there was zero drain on the batteries when the power switch
on the side on the top was turned off when it wasn't in use. The case would then also serve as a long term carry/storage case for up to four 18650 batteries. (Though if the four battery compartments are indeed wired in parallel, you do NOT want to pop out one battery to fire your Cera, and then put it back dead when you're done. Again, this would be a very, very bad idea. The rule would be "once you take a battery out of the case, you can't put it back until it's been externally charged back up to match the other battery's charges in the case".).