This is a USB charged 1.5V battery, there is a LiIon cell, a buck converter and a charge circuit inside.
Behind the black dot on the front is a red and green led, it shows red while charging and green when finished.
Included with the batteries is a 4 way USB charging cable, i.e. any 2A USB charger can charge four batteries simultaneous.
The capacity depends a bit on the load current, but output voltage is stable.
At low current the capacity is also lower, because the internal regulation also needs some current. The battery can last for months at low current draw.
The electronic circuit makes the internal impedance look strange.
The voltage from an electronic circuit is not as stable as battery voltage, with some equipment it will affect performance.
It looks like the buck regulator runs at about 1.4MHz
Conclusion
These batteries has less capacity than normal NiMH, but run at a higher voltage. This makes them ideal for most equipment that has trouble with NiMH batteries. They also weight considerable less than NiMH, this can be significant in some circumstances. There is one disadvantage: Battery meters do not work with them.
The USB charging makes it very easy to find a charger for them.
Notes and links
The batteries was supplied by Blackupe/roca-sup.com for review.
I can’t help noticing that in that case inside the battery the voltage of the li-polymer battery is bucked down to 1.5V and then by the flashlight driver boosted up again to the led voltage.
One of the big problems with these batteries is the misunderstanding and ignorance of the purchasers.
They can be useful but have a fairly narrow band of optimal uses. They work, but aren’t very cost effective for most very low drain applications, nor do they work well in high drain uses. The voltage converter heats up. Not good for camera flashes/strobes.
Some devices that really seem to require the 1.5v and have modest drain do well. Some small devices work better: battery operated beard trimmer, nose hair trimmer, electric toothbrush and the like.
I now have 12 of a brand called [Tenavolt], and generally like them….so far. Long term use to be determined.
Only buy them on special at about $2.50/cell. Full price is exorbitant.