Last September, an organization named Lumafield scanned 1,000 cylindrical lithium-ion batteries to shine a lightweight on the hidden dangers of cheaping out. At roughly the identical time, I discovered myself testing two superior new sorts of AA battery that recharge utilizing USB-C cables.
It gave me an thought. Could we discover the highest USB-C AA batteries by combining my very own anecdotal testing with Lumafield’s scanning tech?
The reply appears to be sure! Knowing what I now know, the Zepath 3600mWh is the only rechargeable lithium-ion AA I’d buy for myself — although USB-C is in the charger, relatively than every particular person cell.
The Zepath is the only one which handed each Lumafield’s take a look at and my take a look at with flying colours. It has increased capability than most of the competitors, it’s simple to make use of, and extremely, it’s one in all the most cost-effective of its type.
These AAs price simply $2.50 per cell, lower than Panasonic’s famed Eneloop nickel-metal hydride (NiMH) batteries, all whereas lasting for much longer than even Eneloop Pros in my Game Boy Advance and high-power flashlight.
It’s $20 for an eight-pack, and that features a clamshell charger with a magnetic snap closure. (Think earbuds case, however a lot bigger.) You can drop as many or as few batteries as you need into any of these eight slots — it’ll fortunately cost three lifeless batteries alongside three full ones, even should you prepare them in a zig-zag sample. It pulls about 10 watts to cost all eight batteries without delay, and below 3 watts for a pair. You can use both a dumb USB-A-to-USB-C cable or the identical type of USB-C PD charger you utilize for your telephone or laptop computer.
Plus, the charger has built-in security precautions that maintain it from charging the improper sorts of batteries. You’ll see eight hidden LEDs shine by the prime of the case to point whether or not a battery’s charging (blinking inexperienced), charged (strong inexperienced), or rejected (blinking crimson) since you unintentionally put an alkaline or NiMH inside as an alternative.
Again, this implies the only USB-C AA battery I like to recommend doesn’t have a built-in USB-C port — however I’ve good causes for that.
When Lumafield analyzed 12 completely different sorts of lithium-ion AA batteries for The Verge, together with designs with each built-in USB-C ports and ones with clamshell USB-C chargers, nearly each battery aside from Zepath was inferior.
Some, like Paleblue, had tried to cram a tiny pouch cell into the battery’s can to make room for the USB-C port. Others, like Coast, use a “can-within-a-can” design, the place a smaller preexisting 14400 cell (14mm x 40mm) nests inside the bigger battery.
Either approach, Lumafield’s Alex Hao discovered most have comparatively poor alignment and one had detrimental anode overhang, the identical worrying defect she found in the earlier examine of 1,000 bigger cylindrical cells. Almost each “Good” we scanned was one with a charging case, together with Philips and Mupoer. But the greatest had been Zepath and the very comparable Runpower — and Zepath prices much less.
“This battery has fairly straight alignment and even anode overhang (AOH). The assembly quality looks good. And the electrodes really maximize the space available in the can. Overall this is a good battery,” is how Hao described the Zepath scans.
I had excessive hopes for batteries from Coast and Nitecore, with their built-in USB-C ports and their model repute for constructing high-quality flashlights for very savvy clientele. (Costco carries the Coast batteries; this is not a fly-by-night model.) But Hao thought Coast’s battery appeared “a little wonky” with unusually low anode overhang. “There still is overhang, so this battery doesn’t seem super unsafe, but I wouldn’t choose it over others in this cohort,” she famous.
And whereas she didn’t assume the Nitecore was harmful, the firm could have a quality-control situation: Both Hao and I observed our batteries felt a bit loosely put collectively, with prime terminals that weren’t all the time straight, and a few of the cells Lumafield scanned had shorter overhangs and worse alignment than others, Hao stated.
The batteries you may wish to keep away from are Spyong, which I see has already been pulled from Amazon since Lumafield found one cell was completely deformed inside and had detrimental anode overhang; NTONPOWER, which had very poor electrode alignment in keeping with Hao; CZVV, which had “virtually non-existent” anode overhang alongside the backside of the cell and has additionally disappeared from Amazon, and surprisingly, Paleblue, a identified model the place our inner pouch cell appeared to have anodes bending inward, which might result in short-circuiting in the event that they ever handle to the touch.
By the time I received Hao’s outcomes again, I didn’t thoughts giving up the USB-C port. I’d already found two sensible downsides to built-in sockets.
The first: shorter battery life. The Zepath lasted a whole hour and a half longer than the Coast in my screen-modded Game Boy Advance at max brightness; they lasted two hours longer in my price range 1,000-lumen flashlight. (See a few of the leads to my embedded video above.) And once I tried two completely different units of Nitecore in that Nebo flashlight, they unusually didn’t work in any respect, both turning the high-power LED right into a flickering mess or refusing to remain on.
The second motive: This technology of built-in USB-C batteries is fiddly to plug and unplug. The sockets really feel too tight on most of them, sufficient that I really feel like I’m risking harm to the battery by forcing it out and in.
And although it is likely to be annoying to recollect to pack the Zepath charging case, it’s additionally potential to overlook the four-headed USB-C charging cables that include the built-in batteries. It’s good to have an built-in port once you’re charging only one or two batteries, although.
Lithium-ion AAs should not the final battery, port or no. The chemistry is nonetheless inherently flammable, even when these ones have a steel casing that protects them from repeated drops, and never all gadgets profit from having batteries that reliably put out round 1.5 volts till they’re about to die.
My flashlight lasted rather a lot longer on low energy with NiMH batteries, which die way more slowly, even when the Li-ion batteries labored higher on excessive. So although I’ve added some Zepath batteries to my dwelling, I gained’t be eliminating Eneloops anytime quickly.