• Kentli makes the best rechargeable lithium-ion AA batteries currently available. They are rated at 2800mWh, and are the only 1.5 V li-on AA batteries, making them the best choice for consumer-grade electronics.
• EXCELLENT makes 3.7V li-on batteries compatible with high drain devices like LED flashlights.

The Details

Not long ago, disposable alkaline batteries enjoyed an undisputed mastery of the AA battery market. Improvements in rechargeable battery technology upended that dominance over the past decade. As we reported in this article, Nickel-Metal Hydride (NiMH) AA batteries such as Panasonic’s Eneloop have made rechargeable options more cost-efficient in the past 10 years.

A 1.5V lithium ion battery has recently been made available to consumers. Lithium ion cells have a high energy density, long cycle life, and have a lower self discharge rate than NiMH batteries. In other words, they last longer and maintain a more even voltage than other types of cells.

Kenli’s 1.5V offering is an ideal choice for everyday household needs. The batteries have the same voltage as a brand-new alkaline battery and won’t overpower devices that just need a stock battery.

2800mWh is a respectable capacity, equivalent to around 1866mAh. By comparison, the Eneloop Pro has a capacity of 2550mAh. Like most NiMH batteries, the eneloop pro is 1.2V.

This equation explains the difference between mWh and mAh:

miliWatt x Hour = Volts x miliAmpere x Hour or mWh = V x mAh. For more on the conversion process, read here.

Other Options

Higher voltage lithium-ion rechargeable batteries are made for high-performance flashlights and cameras, but they are not intended for use with many products. They are higher energy density and rated at 3.7V.

EXCELLENT is one company producing higher energy density lithium ion batteries. Their 18650 batteries have a 2600mAh capacity and high quality cells. They are 3.7V and great for UV or high powered LED flashlights that consume a lot of energy.

One word of warning too consumers: there is currently no standard size for these lithium-ion cells. Make sure to read the dimensions of each battery on Amazon before you buy to guarantee that they will fit in your device.

The post The Best Lithium-Ion AA Batteries appeared first on Reactual.

• If you want the best energy capacity (2550 mAh) — get the Eneloop Pro
• If you want maximum recharge capacity (2100 times) — get the 4th Generation Panasonic Eneloops

Overall, the best rechargeable AA battery is the Eneloop Pro. They have a high energy capacity (2500 mAh), and they perform better than similar high-capacity AAs. They can only be charged 500 times (versus 2100 times for regular Eneloops). But most people will never charge their batteries that many times. For example, if you charged your batteries twice a week consistently, it would take 5 years to reach 500 charges.

Sanyo Eneloop

Top Review Sources:

• Consumer Reports: Recommended
• Doc’s Charger and Battery Reviews: “Good performance for a 2000 mAh rated battery, and fantastic shelf life for a Ni-MH”
• Amazon: 4.5/5.0 (1,600+ reviews)

Eneloops are currently the top rated rechargeable AAs, and we have found them to perform well.  We should also mention Imedion batteries, which are similar to Eneloops but rated at 2400 mAh (this stands for milli Amp hour, and indicates a battery’s energy storage capacity). Eneloops, by comparison, have a lower rated capacity — 2000 mAh (or 1980 mAh according to my informal tests).

You’ll find the Sanyo eneloop AA four pack ($11) on Amazon. You can also buy an eneloop AA four pack with included recharger ($18) as well as an eneloop AA eight pack ($20).

Eneloop Pros

The Eneloop Pro is a high-capacity version of the regular Eneloop cell. The Eneloop Pro has a capacity of 2500 mAh –this is 500 mAh more than the regular Eneloops. Their only potential downside is that they can be charged 500 times — not 2100 times like the regular Eneloops. However, on average most people will charge their batteries about 100-200 times over a 5 year period.

Eneloop Pro batteries are available on Amazon.

Energizer Ultimate

Pros:

• Great for high-drain devices and maximum runtime
• Fantastic shelf life

Cons:

• Not rechargeable

Top Review Sources:

• Consumer Reports: Recommended
• Amazon: 4.5/5.0 (150+ reviews)
• CHOICE Online (Australia): “The ENERGIZER e2 Lithium was by far the top performer in our test”

The Energizer Ultimate is a disposable battery meant for high-drain devices and long periods of time away from another power source. It is the successor to the similar Energizer e2. Like the e2, the Ultimate is a lithium battery. One of lithium’s advantages over other types of batteries is a longer runtime. The Ultimate AA is a 3000 mAh battery that operates at about 1.7 volts; it is able to energize a high-drain device (such as a powerful camera) for a longer period of time than most other batteries. If you have a gadget that needs the higher voltage, or if you need a battery that will last in a high-drain device for as long as possible, lithium is a great option. Another lithium advantage is its 10+ year shelf life, making it a good backup battery to have around for emergencies. Lithium batteries also operate in sub-freezing temperatures, unlike alkaline disposables.

The Energizer Ultimate four pack ($5) is available on Amazon. Also for sale is an eight pack ($15).

Duracell CopperTop

Pros:

• Low initial cost
• Long shelf life

Cons:

• Not long-term cost-effective

Top Review Sources:

• Amazon: 4.5/5.0 (125+ reviews)
• PC Magazine: Longest runtime in flashlight test (of seven batteries tested)
• CandlePowerForums.com Alkaline Battery Shoot Out: 4^th place (of 19 batteries tested for watt-hours)

Duracell CopperTop batteries use alkaline technology to deliver reliable performance at a low cost per battery. While rechargeable batteries will save you money in the long run, disposable alkalines like the CopperTop have advantages such as lower initial cost and longer shelf life (7+ years). CopperTops are not suited for high-drain devices; they won’t last as long as NiMH or lithium batteries. However, if you use batteries very infrequently or need a long-lasting, inexpensive solution for a smoke detector or rarely-used remote control, the CopperTop offers a compelling price/performance balance.

The Duracell CopperTop 20 pack is for sale on Amazon.

See also our extensive review of rechargeable batteries and chargers on MetaEfficient.

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