Disposable Batteries — explained and compared
(Alkaline, Lithium, Heavy Duty, General Purpose, Oxyride, in AAA, AA, C, D, 9V sizes)

If you came to this page first, you'll want to check out the Comparison Tables, which are much more helpful.

Alkaline -- Popular, but other kinds are usually better

• Available everywhere
  
• Decent amount of power
• Exceptional shelf life
• Higher initial voltage than NiMH
• One set is cheap (though pricier in long-run since not rechargeable)

• Not rechargeable (at least not by normal means)
  
• Standard alkalines don't work well in high-drain devices (special premium alkalines do, but NiMH batteries are even better)
• More prone to leaking than other batteries (and damaging electronics)
  
• Harder to find a place to recycle them
  

• High-drain devices.  Alkalines aren't good for high-drain devices because they can't supply the juice fast enough.  So they have short run-time, if they work at all.
• Going through batteries quickly.  If that's the case, you need a rechargeable battery.
• Need high voltage.  NiZn is probably what you need.
• Long shelf life.  Other batteries offer decent shelf life, and can either be recharged or last longer, and aren't nearly as susceptible to leaking.  For smoke detectors, Lithiums are best, since they can last 7 years.
  

Where to buy.  Man, if you can't find alkaline batteries, you've got bigger problems. :)

High-drain performance.  Standard alkalines don't work well (or at all) in high-drain devices like digital cameras, because they can't pump out the juice fast enough.  There are special high-drain versions like Duracell Ultra, Energizer Advanced Formula, and Kodak Photolife which do work, but high-drain devices go through batteries quickly no matter what kind of battery, so the better solution for high-drain devices is to use rechargeables so you're not always buying batteries.

Capacity.  Alkalines have decent capacity, though the capacity is rarely stated on the packaging.  That's not too much of a problem, because there's not much difference in capacity from brand to brand (as long as you're comparing standard to standard, and high drain to high drain). They're all pretty much the same, despite the manufacturers' commercials. Consumer Reports found that the spread between the best and worst alkalines was only 9-15%. Tests by ZBattery also showed little difference between name-brand alkalines.  Someone on a web forum said that it's possibly to squeeze more life out of seemingly dead alkalines by tapping them against a hard surface, but I have yet to test that theory.

Voltage.  The initial voltage is 1.5V, which is just about perfect for a fresh battery.  The lower-voltage NiMH's (1.2V) might not be powerful enough for some applications. (more)  However, as you use an alkaline, its voltage drops faster than a NiMH would, so you can often get more runtime out of a NiMH.  So this means that which battery gives more runtime in your device depends on your device.  For some devices it'll be alkalines, for some it'll be NiMH.  (Though in general, for various reasons, I prefer NiMH to alkaline.)

     When your alkalines are too dead to power higher-drain devices, they'll have a second life in remote controls and possibly clocks, which need only a little voltage to run.  Also, you can make a battery pack with a battery holder from Radio Shack or Amazon to milk your alkalines completely.  For example, I have some battery-powered Christmas lights that expect 3 x AA, or 4.5V.  I have some alkaline AA's that are around 1.15V.  (I don't buy alkalines, I salvaged these from elsewhere.)  Three of them would be only 3 x 1.15V = 3.45V, which would be kind of weak for the lights.  But putting four of them in a battery pack gives me 4 x 1.15V = 4.6V, which is just about perfect.

Charging & Cycle Life.  There are a few battery chargers that purport to charge standard alkalines.  This is pretty much a worthless gimmick.  First off, the batteries can be charged only a few times if you've run them down all the way (which is how most people use batteries).  And the newer high-drain alkalines are especially resistant to recharging.  Next, the batteries are more prone to leaking, both during and after charging.  If they leak while inside your device, they can easily ruin it.  Oh, and you'll need a special charger.  A standard charger won't work.  (For hobbyists, Afroman offers an article about how to build your own alkaline recharger.)

   Why anyone would want to go through all this is beyond me.  If you want to recharge your batteries (and I hope you do), just get a real rechargeable, like NiMH.

   If you must recharge standard alkalines, and you've purchased the special charger for doing so, then you'll get the most recharge cycles by keeping your alkalines "topped off".  That is, the sooner you charge them, the better. You'll get much more total energy out of the battery over its life that way.  Also, be aware that alkalines charge much more slowly (~8-16 hours) than real rechargeables. (TechLore)

Leaking.  Alkalines leak more frequently than any other kind of battery.  If you want to avoid leaks, don't use alkalines!

     Three of the biggest battery-makers offer to replace any equipment damaged by their batteries.  The Rayovac and Energizer guarantees seem to cover leakage, but the Duracell wording is a little more ambiguous (and they wouldn't answer my request for clarification).  So if you do use alkalines, choosing Rayovac or Energizer might afford some measure of insurance.

• Rayovac: "Guarantee on all batteries*. We will replace or repair at our option, any device damaged by this battery if sent with batteries prepaid to the address below."
• Energizer: "We will repair or replace, at our option, any device damaged by these Energizer® batteries.... Contact 1-800-383-7323."
  
• Duracell: "Should any device be damaged due to a battery defect, we will repair or replace it at our option if it is sent with the batteries, postage paid to [the address below]."
  

(I want to call out Duracell for special mention for having especially pathetic customer service.  I emailed them and asked whether leaking alkalines were covered under the "damaged due to a battery defect" clause.  In response, they sent me a generic form letter about their replacement policy which said nothing about leaking alkalines.  I wrote back, pointing out that they didn't answer my question, and asking again whether leaking alkalines were covered?  They responded with the SAME useless form letter!  I wrote a third time, asking them to answer my question rather than sending me useless form letters, but they never replied. If you want a guarantee against leaking batteries, don't buy Duracell.)

Things that increase the chances of alkaline leakage include:

• Trying to charge them
• Mixing fresh and used batteries in the same device
  
• Mixing alkalines and other types of batteries
  
• Long exposure to high temperatures
• Deep discharging
• Being dead (don't let dead batteries sit in a device)
• But sometimes alkalines seem to leak for no apparent reason
  

    The reason why mixing fresh/used or alkaline/other batteries together increases the chance of leaking is that one battery will likely become exhausted first, and it can go to very low or even negative voltage levels, and low or negative voltage greatly increases the chances of leakage. (Energizer, PDF) 

DEALING WITH LEAKS.  Don't touch the leaked material.  If you accidentally touch it then flush the affected area for 15 minutes with lots of water.

If an alkaline leaks, even a little bit, throw it away or recycle it.  Don't try to use it again—it's just gonna continue leaking.

If an alkaline leaked, clean up as much of the solid or liquid matter as you can with tissue paper and/or cotton swabs.  After that, use cotton swabs with vinegar or lemon juice.  The acid will neutralize the leaked alkaline material to prevent further corrosion.  An old toothbrush or tiny wire brush might help.  (If using one of those, wear safety glasses, so you don't flick the solution into your eyes.)

Temperature.  Alkalines perform poorly at subfreezing temperatures (reduced capacity), as this chart from Energizer (PDF) shows.  Nickel Zinc and Lithium are better for below-freezing applications.  Alkalines maintain their voltage and deliver enough current in freezing temperatures, (source) but capacity is a problem.

Recycling.  Here's another reason not to use alkalines:  They're harder to recycle than rechargeable batteries.  Alkalines aren't nearly as hazardous as NiCd's, but they do contain useful metals, and it's better for those metals to be reclaimed by recycling rather than strip-mining mountains.  In Europe recycling is easy—every store that sells batteries must take them back for recycling too.  In the U.S. it's tougher:  while recycling for NiMH, NiZn, and NiCd is widespread (see RBRC), there just aren't nearly as many places to recycle alkalines.  That's because the process just isn't as cost-effective for the recyclers.  A handful of retailers collect do collect them, though I don't know of any who collect them at all their nationwide stores.  For most of us, that means our only option is to mail them to a recycling company, as well as pay a small fee to that company.  I hope retailers who read this will start offering to collect alkalines from their customers as an extra service, and then ship the batteries to the recyclers by freight.

    In California, all batteries are considered hazardous materials, so they can't just be thrown in the trash.  Check with your county government about collection facilities in your area.

    Alkalines used to have a fair amount of toxic mercury, but Congress banned mercury in batteries except in trace amounts starting in 1996.  (There's an exception for button batteries, the circular kind that go in watches and calculators, which can still have mercury.  Radio Shack accepts those for recycling.)

More info: Energizer's alkaline FAQ (PDF), Energizer tech specs (PDF)

Lithium — lots of power, but expensive, and can't be recharged

• Work great in high-drain devices
• Work well in sub-freezing temperatures (source, PDF)
  
• Loooong shelf life.  (9V varieties can power smoke alarms for a few years.)
• Lightweight - 1/3 the weight of alkalines (source)

• No good rechargeable version, except for 9V.  Compared to NiMH, rechargeable lithiums have less capacity, cost more, and aren't very reliable (but rechargeable 9V lithiums are good.)
  
• More expensive
• High voltage can fry devices  (Burned out the bulb in PC Magazine test.)
  
• Can't fly with extra batteries in checked luggage (must be in carry-on). (DoT)
  
• Good luck finding a place to recycle them
• Small possibility of explosion

There's usually a better choice than lithiums.  They can't be recharged (9V can, but not other sizes), and the only benefits they offer over other batteries are that they're lightweight (who cares?) and that they work in subfreezing temperatures.  I can think of only one case where lithiums have a clear advantage:  Smoke alarms. A 9V lithium battery in a smoke detector often lasts a few years. This is nice especially given that smoke detector batteries are bothersome to replace.  And when you go through only one battery every few years, rechargeability becomes less important.

Explosion hazard.  It's rare for lithium batteries to explode, but they're more likely to than other kinds of batteries.  That's why you can't send them in the U.S. mail and why they can't go in your checked luggage when you fly.  Here's a story about someone who nearly lost a finger when the lithium cell in his flashlight exploded.

High-Drain Performance.  Lithiums work better in high-drain devices than alkalines, as the chart at right shows. (Energizer, PDF)  (But then again, so do NiMH, NiZn, and high-drain Alkalines, without most of the downsides of lithium.)

   Energizer says the Advanced flavor lasts 4x longer in digital cameras than its Energizer Max alkaline, and Ultimate flavor lasts 8x as long.

Voltage drop.  Lithiums drop their voltage suddenly, like NiMH/NiCds. (source)

Don't confuse AA Lithiums with Lithium-Ion battery packs (like the kind that come with laptops and many cell phones). Those Lithium-Ion packs are rechargeable, but only when they're installed in the device they're powering, or in a special charger. Rechargeable Lithium-Ions are not available in AAA-D sizes, though they're available in the 9V size.

Shelf Life.  At cool temperatures (68°F, 20°C), a lithium battery will retain 90% of its charge for about 15 years.  At higher temperatures the shelf life goes down, but it's still pretty long (e.g., 90% after four years at 104°/40°C). (Energizer PDF, p. 14)

Temperature.  Lithiums work well in freezing temperatures, and are rated for a lower temperature than any other kind of battery (-40°F).  Voltage and current flow remain good in cold temperatures. (source)   I haven't yet found a source about capacity in cold temps, but I expect it to be good because lithiums are rated for cold-temperature use.

More:  Energizer's tech specs (PDF)

Carbon Zinc  (aka General Purpose, Heavy Duty, Zinc Chloride)

Pros:

• Really cheap
  
• Long shelf life
• An acceptable battery for low-drain devices like clocks, radios, and remote controls
  

• Lowest capacity of any battery besides NiCd's
  
• An alkaline is usually better, even though it costs slightly more
  

Summary. This is the original chemistry for household batteries, dating back to the 1800's!  And it's still being used today, though of course better batteries have come along in the meantime.  In fact, alkalines have all but replaced Carbon Zinc's.  In any case where a Carbon Zinc would work, an alkaline will last even longer.  The alkaline costs a little more, but it lasts 2-11x as long, making it the far better value. (Energizer)

      If a package of batteries doesn't say what chemistry it is, it's almost certainly Carbon Zinc, Leclanché flavor.  (See below.)

     For years if you bought something and batteries were included, they were almost certainly Carbon Zinc, because that was the cheapest batteries that the manufacturer could get away with.  But alkalines aren't really that much more expensive, and some manufacturers don't wish to appear cheap, so alkalines are being bundled with new devices more and more.

Naming.  Some sources call these Zinc Carbon instead of Carbon Zinc, but I'll use the latter.  And I'll abbreviate to CZ for short.

    There are two flavors of CZ batteries:

1. GENERAL PURPOSE.  These are the original CZ, using the Leclanché method.
2. (SUPER) HEAVY DUTY.  These use the newer method, Zinc Chloride, which offers 2-3x the capacity of Leclanché batteries, better performance at lower temperatures, and are less prone to leaking.  They were "Heavy Duty" compared to Leclanché batteries when they were introduced decades ago, but compared to modern batteries, "Heavy Duty" are really "Super Extremely Light Duty".
   

Nickel Oxyhydroxide (NiOx)— discontinued

Pros:

• Exceptionally powerful (think brighter flashlights)
  
• Work great in high-drain devices
• Slow self-discharge rate (i.e., long shelf-life)
  

• No longer being made
• Can't be recharged (at least not normally)
  
• High voltage of 1.7 can burn out lights and some sensitive electronics
• Not available in C & D sizes, even when they were available
  

Summary.  After forty years, in 2005 NiOx became the first new non-rechargeable battery format to challenge alkalines.  But they were too little, too late, since in most cases rechargeable batteries like NiMH or NiZn provide adequate power and are cheaper in the long run.

Manufacturers.  Panasonic was first out of the gate in 2005 with their Oxyride brand (2004 in Japan), but quickly discontinued them circa 2009.  Duracell followed with the Duracell Ultra PowerPix, but discontinued theirs circa 2011.

Performance. NiOx batteries last more than twice as long as standard alkalines in digital cameras, and around 1.5x as long as high-drain alkalines like Duracell Ultra.  But they have worse performance in low-drain devices.

    NiOx batteries put out 1.7 volts, higher than the 1.5 from an alkaline, and way higher than the 1.2 volts from an NiMH.  The extra voltage should be safe for most devices, though I expect light bulbs may burn out a bit quicker.  One bulb burned out in PC Magazane's test.

    J. Harper's independent tests show that Oxyrides are better in freezing temperatures than alkalines.  (Alkalines have the worst performance at subfreezing temperatures.)

Charging.  NiOx batteries can't normally be recharged.  One person claims to be able to recharge oxyrides, but only with a slow charger, and only for six cycles.  That's not nearly as much as an NiMH, which can be recharged hundreds of times.

More on Oxyride batteries:

• Oxyride review in the New York Times, David Pogue
  
• Oxyride battery tests. Shows that oxyrides last much longer in cold temperatures vs. alkalines. They underperformed alkalines at normal temperatures, but that's because of the nature of the test—a constant drain.  In more typical use, oxyrides will beat alkalines.
• Wikipedia on Nickel Oxyhydroxide batteries