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 concept. 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 one rechargeable lithium-ion AA I’d purchase for myself — regardless that USB-C is within the charger, somewhat than every particular person cell.
The Zepath is the one one which handed each Lumafield’s take a look at and my take a look at with flying colours. It has increased capability than a lot of the competitors, it’s simple to make use of, and extremely, it’s one of many most cost-effective of its variety.
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 for those who organize 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 sort of USB-C PD charger you employ on your telephone or laptop computer.
Plus, the charger has built-in security precautions that hold it from charging the fallacious sorts of batteries. You’ll see eight hidden LEDs shine by way of the highest of the case to point whether or not a battery’s charging (blinking inexperienced), charged (strong inexperienced), or rejected (blinking purple) since you unintentionally put an alkaline or NiMH inside as an alternative.
Again, this implies the one 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 contained in the bigger battery.
Either method, Lumafield’s Alex Hao discovered most have comparatively poor alignment and one had adverse anode overhang, the identical worrying defect she found within 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 very best have been Zepath and the very comparable Runpower — and Zepath prices much less.
Scans of 4 completely different Zepath cells. “The additional Zepath batteries we scanned were consistent in their quality,” writes Hao.
“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 isn’t a fly-by-night model.) But Hao thought Coast’s battery regarded “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.
Two completely different Coast batteries; the layers of the wound battery have peaks and valleys.Image: Lumafield
And whereas she didn’t assume the Nitecore was harmful, the corporate could have a quality-control subject: 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 first Nitecore that Lumafield scanned (left) regarded nice, however high quality was inconsistent.Image: Lumafield
The batteries you may need to keep away from are Spyong, which I see has already been pulled from Amazon since Lumafield found one cell was solely deformed inside and had adverse anode overhang; NTONPOWER, which had very poor electrode alignment in accordance with Hao; CZVV, which had “virtually non-existent” anode overhang alongside the underside of the cell and has also disappeared from Amazon, and surprisingly, Paleblue, a identified model the place our inner pouch cell appeared to have anodes bending inward, which may result in short-circuiting in the event that they ever handle to the touch.
This Spyong battery was by far the worst that Lumafield scanned, with deformation and adverse anode overhang.Image: Lumafield
By the time I acquired 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 complete 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 budget 1,000-lumen flashlight. (See a few of the ends in my embedded video above.) And after 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 purpose: This era 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.
I want Nitecore had higher high quality management! Among different issues, the second battery from the left has a crooked button prime; one other four-pack I purchased had the identical downside.Photo by Sean Hollister / The Verge
And although it is perhaps annoying to recollect to pack the Zepath charging case, it’s additionally attainable to neglect the four-headed USB-C charging cables that include the built-in batteries. It’s good to have an built-in port while you’re charging only one or two batteries, although.
Lithium-ion AAs will not be the final word battery, port or no. The chemistry continues to be inherently flammable, even when these ones have a metallic 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 loads longer on low energy with NiMH batteries, which die much more slowly, even when the Li-ion batteries labored higher on excessive. So regardless that I’ve added some Zepath batteries to my residence, I received’t be eliminating Eneloops anytime quickly.
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