BU-106a: Choices of Primary Batteries

Knowing the difference in run-time performance


Zinc-carbon, also known as carbon-zinc or the Leclanché battery, is one of the earliest and least expensive primary batteries. They often come with consumer devices when the batteries are included.


Alkaline-manganese, also known as alkaline, is an improved version of zinc-carbon. Lewis Urry invented alkaline in 1949 while working with the Eveready Battery Company Laboratory in, Ohio, USA. The first zinc-carbon invented by George Leclanché in 1859 was wet.

Alkaline delivers more energy at higher load currents than zinc-carbon. Furthermore, a regular household alkaline provides about 40 percent more energy than the average Li-ion but alkaline is not as strong as Li-ion on loading. Alkaline has very low self-discharge and does not leak electrolyte when depleted as the old zinc-carbon does, but it is not totally leak-proof.

All primary batteries produce a small amount of hydroxide gas on discharge and battery-powered devices must make provision for venting. Pressure buildup in the cell can rupture the seal and cause corrosion. This is visible in form of a feathery crystalline structure that can spread to neighboring parts in the device and cause damage.

Lithium Iron Disulfide (Li-FeS2)

Lithium Iron Disulfide (Li-FeS2) is a newcomer to the primary battery family and offers improved performance compared to alkaline. Lithium batteries normally deliver 3 volts and higher, but Li-FeS2 has 1.5 volts to be compatible with the AA and AAA formats. It has a higher capacity and a lower internal resistance than alkaline. This enables moderate to heavy loads and is ideal for digital cameras. Further advantages are improved low temperature performance, superior leakage resistance and low self-discharge, allowing 15 years of storage at ambient temperatures.

The disadvantages of the Li-FeS2 are a higher price and transportation issues due to the lithium metal content in the anode. In 2004, the US DOT and the Federal Aviation Administration (FAA) banned bulk shipments of primary lithium batteries on passenger flights, but airline passengers can still carry them on board if the allotted lithium content is not exceeded. Each AA-sized Li-FeS2 contains 0.98 grams of lithium; the air limitation of primary lithium batteries is 2 grams (8 grams for rechargeable Li-ion). This restricts each passenger to two cells but exceptions have been made in which 12 sample batteries can be carried. (See BU-704a: Shipping Lithium-based Batteries by air.)

The Li-FeS2 includes safety devices in form of a positive thermal coefficient (PTC) that limits the current at high temperature and resets when normal. The Li-FeS2 cell cannot be recharged as is possible with NiMH in the AA and AAA formats. Recharging, putting in a cell in backwards or mixing with used or other chemistries cells could cause a leak or explosion. (See BU-304a: Safety Concerns with Li-ion.)

Figures 1 and 2 compare the discharge voltage and internal resistance of Alkaline and Li-FeS2 at a 50mA pulsed load. Of interest is the flat voltage curve and the low internal resistance of Lithium; Alkaline shows a rapid voltage drop and a permanent increase in resistance with use. This shortens the runtime, especially at an elevated load.

Voltage and internal resistance of Alkaline on discharge

Figure 1: Voltage and internal resistance of alkaline on discharge.

The voltage drops rapidly and causes the internal resistance to rise.

Source: Energizer

Voltage and internal resistance of Lithium on discharge

Figure 2: Voltage and internal resistance of Lithium on discharge.

The voltage curve is flat and the internal resistance stays low.

Source: Energizer


Lithium-thionyl chloride (LiSOCI2 or LTC)

Lithium-thionyl chloride (LiSOCI2 or LTC) is one of the most rugged lithium-metal batteries. The ability to withstand high heat and strong vibration enables horizontal drilling, also known as fracking. Temperatures can go high and some LTC are said to operate from 0°C to 200°C (32°F to 392°F). Other uses are in medical and sensor applications.

With a specific energy of over 500Wh/kg, LTC offers twice the capacity of the best Li-ion. The nominal voltage is 3.50V/cell; the end-of-discharge cut-off voltage is 3.00V. The runtime is not based on capacity alone; thermal conditions and load pattern also have an effect. Constant current is more enduring than pulsed load; a phenomenon that applies to most batteries.

Like alkaline, lithium-thionyl chloride has a relatively high resistance and can only be used for moderate discharge loads. If stored for a time, a passivation forms between the lithium anode and the carbon based cathode that dissipates when applying a load. This layer protects the battery by granting low self-discharge and a long shelf life. (See BU-701: How to Prime Batteries.)

LTC is one of the most powerful battery chemistries and should only be used by trained workers. For safety reasons, this battery is not used in consumer devices.


Lithium manganese dioxide (MnO2 or Li-M)

Lithium manganese dioxide (MnO2 or Li-M) is similar to LTC but has a lower specific capacity and is safe for public use. The voltage is 3.0–3.30V and the specific energy is about 280Wh/kg. Li-M is economically priced, has a long life and allows moderate loads but can deliver high pulse currents. Operational temperature ranges from -30°C to 60°C (-22°F to 140°F). Typical uses are meter sensing, medical devices, road toll sensors and cameras.


Lithium sulfur dioxide (LiSo2)

Lithium sulfur dioxide (LiSo2) is a primary battery with a voltage of 2.8V and an energy density up to 330Wh/kg. It offers a wide temperature range of -54°C (-65°F) to 71°C (160°F) with a projected shelf life of 5–10 years at room temperature. LiSo2 is inexpensive to make and is commonly used by the military, such as in the Iraqi war, but it is giving way to the more superior Li-M.

CAUTION  The chemical components that provide high energy density to lithium-based batteries can also cause safety hazard if misused. LTC and Li-M are safe but workers handling these batteries must be familiar with the safety precautions, transportation and disposal. Make certain that the batteries are protected from heat, short circuit, and all physical or electrical abuses.

Last Updated 2015-11-27

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On May 29, 2012 at 11:25pm
TVSSubRamanian wrote:

Articles are excellent and are highly Informative.I wish that I get more and more opportunities on practically application of these and disseminate these technically information among interested students

On May 29, 2012 at 11:28pm
TVSSubramanian wrote:

My comments earlier to be read as practical and technical informations

On November 10, 2012 at 9:52am
Jesse Ifarunde wrote:

Excellent article.

On November 7, 2014 at 2:31pm
Michael wrote:

Read the whole 20+ articles here but not being an electrician or anything related to the science leaves me with a question if I may. It all comes down to $$ in my case and trying to find out given an equal battery (or what seems to be) is it worth paying the extra bucks for certain batteries. In my case I am mainly referring to AA, AAA, and small batteries found in watches, calculators etc. Now yes I’ve seen the really cheap batteries not being worth it at all as they don’t last long but what are good tips regarding such purchases. Is Duracell really that much better than Eveready, Panasonic or others? As you know even the same manufacturer has the same type of battery which isn’t the same, and having different prices. Thanks

On November 23, 2014 at 4:45am
Jeff wrote:

Alkaline cells have only one role and are not worth purchasing at all in anything else. I use them only in clocks. They have too much of a tendency to leak to be trusted in any of my remotes. I use rechargeable cells in everything else. The development of the lifepo cells have been a huge advance. I really could care less if Duracell makes a better alkaline cell than everyone else. Alkaline cells are mostly junk. They can’t handle high current loads, leak when exhausted, expensive, non-rechargeable, and have a poor discharge curve. They perform well only when compared to carbon-zinc and zinc chloride cells. Why people still purchase them is beyond me. The cursed cells come included in a lot of items and I save them for my clocks.  In fact, if I were to actually purchase a primary cell for my clocks, it would be the zinc chloride chemistry as they perform nearly as well in low drain devices for far less cost. As far as watch batteries, silver oxide is superior to alkaline as the little alkaline cells swell up as they are exhausted. Lithium is the way to go for primary cells and batteries. In my small flashlights and laser pointer which normally uses 3 LR44 cells in series, I have been able to substitute a rechargeable 10180 li-ion cell with superior results. There is now an equivalent to to the alkaline LR44 cell using LiFeS2 chemistry, but until the prices come down on those, I will continue to use the silver oxide cells with the EPX76 superior to the 357 types in my experience.

On November 23, 2014 at 9:28am
Michael wrote:

Jeff thanks. It seems to me that perhaps you are suggesting the rechargeables have improved significantly since 5 years ago. My problem in the past with such cells was that they lost power too quickly. I’d rather pay a little more than have to change and charge batteries that often. I say ‘‘pay a little more’’ because to me after calculating the price of such rechargeables and the charger itself I didn’t really see much of a difference compared to the stats. This does seem to change from manufacturer to manufacturer, type to type and construction to construction of all parts involved. I still have the original battery inside my ipod 3G making it I think 6 years old now and yet other similar batteries needed replacement after a year or so—camera, cell phone. I find it interesting whereby you say alkalines ‘can’t handle high current loads’ I didn’t know batteries were used for high current loads with a few exceptions. When I think of such batteries I think of where I use them: a mouse. keyboard, stylus pen, mp3 player, xbox controller, flash light, clock, whereby the xbox is the only one that drains them quickly enough all others last a long time compared to those things I have which have their own rechargeables inside them: cell phone, ipod, camera. I also have a camera flash which has both its own rechargeable pack (with AA’s) or whereby I can place alkalines instead and alkalines last a lot lot longer—though yes, in this case there is a difference in price

On January 20, 2015 at 12:23am
Jeff wrote:

Hi Jeff, Where are you from, Why you are so professional about the battery? I want to learn more from you. zzrm316@163.com

On September 19, 2015 at 5:49am
John L Griffin wrote:

This seems so simple to me, strictly a layman with little or no electrical background.
Check out the Consumer Reports website and see their ratings and costs.  The result is buy them at Costco.  The same answer you’ll get for almost any consumer product they carry.  So just remember these two icons: Consumer Reports and Costco.

On October 17, 2015 at 6:11am
hrncirik wrote:

at cca 7 cm text ..In spite (hdroxide) /hydrogene/