TRUTH and BATTERIES 


BATTERIES ARE 2000 YEARS OLD

Electric batteries have come a long way since some unknown Parthian first stuck some iron and copper cylinders into a jar of acidic grape juice. The things that power our cameras today, 2,000 years later, work on the same basic principle, though they sure don't look like a clay jar. 

But there is some evidence to suggest that they may possibly have been the first known people to harness the power of electricity too. Central to this theory was the discovery of a ‘battery’ in 1938 by a German archaeologist called Wilhelm Konig.  The battery consists of a little pot, dated 250BC, containing a roll of thin copper surrounding a central iron rod. 

Wilhelm Koenig surmised that with a liquid such as grape juice or vinegar in the pot an electrical current would be created by the potential difference between the iron and copper. It’s not an advanced design by any means, but the idea that electricity could be harnessed like this at all would pre-date the known invention of the electrical cell by almost two thousand years.

The clay has been replaced by plastic, the grape juice has been replaced by an electrolyte gel, and the iron and copper are now lithium, cobalt, or carbon. Pioneer work with the lithium battery began in 1912 under G.N. Lewis but it was not until the early 1970s when the first non-rechargeable lithium batteries were sold. 

Lithium, if you were paying attention in high school chemistry is the lightest of all metals, has the greatest electrochemical potential and provides the largest energy density for weight.   

And it can in the wrong format, the Dark Side, burn, eat stainless and possibly explode.  It is possibly the most dangerous battery.   Here are some facts  I am happy to share with you, as the industry does not tell you all. I have fifty years experience and what I tell you is facts.


COMMON PHOTO BATTERY FACTS  (TRUTH) 

AGING
All batteries age, it is a fact of life so it is no surprise that lithium-ion batteries also age, most manufacturers remain silent about this issue.  Try very silent, shelf lives of one to two years means they better get sold.  Some capacity deterioration is noticeable after one year, whether the battery is in use or not. The battery frequently fails after two maybe three years with usage.  And then you find out the replacement costs more than the product it came in. JUST LIKE PRINTER INK, the ink costs more than the printer.

LITHIUM CAN BE UNSTABLE and is STILL UNSTABLE
Lithium battery technology got a bad rap in 1991 when one of the old-style solid-metal batteries caught fire. Took out the SONY plant.  The entire plant.  Four fires and explosions, later, the Lithium computer batteries took out the laptops.  And the smart Japanese decided to outsource their production to China.  We called it giving the Chinese their due. Fortunately for the Chinese proletariat, (not for the people) they had many willing workers who paid the ultimate price of Lithium production.

NO MEMORY - OLD NEWS
The phrase belongs to older nickel-cadmium (NiCad or Ni-Cd) batteries. This is why manufacturers recommend that you go ahead and plug in your charger when the device gives you its low battery alert or when you are done with a shoot.  Memory problems do not pertain to Lithium nor NiMH. 

CHARGE TIMES
Battery makers say the first 2 hours of charging takes your battery to 80% of its full capacity. During the next 2 hours, the batteries will trickle-charge slowly to top off.  IF YOU ARE USING A SMART CHARGER.  But since there’s no memory effect, you don’t have to devote 4 hours to topping off the battery with the appropriate charger for the device.  The caveat is the speed of the charger which is not mentioned, nor the maximum MAH capacity of the battery.

TRAVEL WITH LITHIUM BATTERIES  LIKE CANON BP-511
 
If original packaging (those little plastic coffins) are not available for these spare batteries when traveling,  effectively insulate the battery terminals by using good electrical tape over the contacts, not the cheap gummy fabric type that leaves residue.  Or 3M paint tape, the blue stuff.

FOR IDIOTS WHO DON’T BELIEVE ME
If Lithium contacts internally, you will experience a life changing experience, called a boomer or fire.  If you must carry a battery-powered device in any baggage, package it properly to prevent inadvertent activation. 

Being in the battery business dealing on a daily basis exclusively with photographic packs, cell phone, walkie talkies (police and fire department rebuilds)  UPS, motorcycle and car batteries, we have respect for Lithium.  Customers will get mad at their cellphone batteries and slam them down on our counter.  

Unfortunately,  one customers hand stopped the fire.  Our counter was OK, it was covered in plate metal and rubber but the battery went up and he has a burn and mark for the rest of his life.  Looked like he put a cigarette, well a cigar out in his hand.


BASIC RECHARGEABLE

POPULAR BATTERY CHEMISTRIES

NICKEL METAL HYDRIDE (Ni-MH)  AAA-AA-C-D - These batteries were made to be environmentally friendly and with a higher capacity than NI-Cad.  The smoke signals read simple replacement for NI-Cad,  it was praised it as a more powerful battery option BUT,  it produces more internal resistance and its associated heat generation. 

It is this heat production that’s causes some photographic flash units to overheat and is 75% of the problem, and that leads to shutdowns. Heat is what is produced when the battery is be charged or discharged.  Up to the safety threshold of 130 degrees Fahrenheit.  

This damages the battery, and the result is the NI-MH gives you less re-charges, and a shorter life cycle.  Metal hydride batteries are not well known for cold weather performance.   So why the popularity of NiMH?  Simple, it is CHEAP, CHEAP,  CHEAP, good advertising and a profit maker. 

LITHIUM AND LI-ION BATTERIES - RECHARGEABLE - Li-Ion and NiMH camera batteries are considered secondary batteries, which means that it can be recharged with its designated camera battery chargers. Heavy users such as professionals and avid enthusiasts will benefit from the economic cost-per-use value of rechargeable battery packs. However, rechargeable camera batteries will perform considerably less in comparison to its brethren primary batteries. Another benefit to rechargeable camera batteries is the benefit to the environment.

LITHIUM-ION SAFETY CONCERNS ( BATTERY UNIVERSITY.COM)
When Sony introduced the first lithium-ion battery in 1991, they knew of the potential safety risks. A recall of the previously released rechargeable metallic lithium battery was a bleak reminder of the discipline one must exercise when dealing with this high energy-dense battery system. 

Pioneering work for the lithium battery began in 1912, but is was not until the early 1970's when the first non-rechargeable lithium batteries became commercially available. Attempts to develop rechargeable lithium batteries followed in the eighties. These early models were based on metallic lithium and offered very high energy density. 

However, inherent instabilities of lithium metal, especially during charging, put a damper on the development. The cell had the potential of a thermal run-away. The temperature would quickly rise to the melting point of the metallic lithium and cause a violent reaction. A large quantity of rechargeable lithium batteries had to be recalled in 1991 after the pack in a cellular phone released hot gases and inflicted burns to a man’s face. 

Because of the inherent instability of lithium metal, research shifted to a non-metallic lithium battery using lithium ions. Although slightly lower in energy density, the lithium-ion system is safe, providing certain precautions are met when charging and discharging. Today, lithium-ion is one of the most successful and safe battery chemistries available. Two billion cells are produced every year. 

Lithium-ion cells with cobalt cathodes hold twice the energy of a nickel-based battery and four-times that of lead acid. Lithium-ion is a low maintenance system, an advantage that most other chemistries cannot claim. There is no memory and the battery does not require scheduled cycling to prolong its life. Nor does lithium-ion have the sulfation problem of lead acid that occurs when the battery is stored without periodic topping charge. Lithium-ion has a low self-discharge and is environmentally friendly. Disposal causes minimal harm.

Long battery runtimes have always been the wish of many consumers. Battery manufacturers responded by packing more active material into a cell and making the electrodes and separator thinner. This enabled a doubling of energy density since lithium-ion was introduced in 1991. 

BUT  The high energy density comes at a price. Manufacturing methods become more critical the denser the cells become. With a separator thickness of only 20-25µm, any small intrusion of metallic dust particles can have devastating consequences. Appropriate measures will be needed to achieve the mandated safety standard set forth by UL 1642. Whereas a nail penetration test could be tolerated on the older 18650 cell with a capacity of 1.35Ah, today's high-density 2.4Ah cell would become a bomb when performing the same test. UL 1642 does not require nail penetration. Lithium-ion batteries are nearing their theoretical energy density limit and battery manufacturers are beginning to focus on improving manufacturing methods and increasing safety. 

RECALL OF LITHIUM-ION BATTERIES 
With the high usage of lithium-ion in cell phones, digital cameras and laptops, there are bound to be issues. A one-in-200,000 failure rate triggered a recall of almost six million lithium-ion packs used in laptops manufactured by Dell and Apple. Heat related battery failures are taken very seriously and manufacturers chose a conservative approach. The decision to replace the batteries puts the consumer at ease and lawyers at bay. Let's now take a look at what's behind the recall. 

Safety issues are enticing battery manufacturers to change the manufacturing process. According to Sony, contamination of Cu, Al, Fe and Ni particles during the manufacturing process may cause an internal short circuit.  A mild short will only cause an elevated self-discharge. 

Little heat is generated because the discharging energy is very low. If, however, enough microscopic metal particles converge on one spot, a major electrical short can develop and a sizable current will flow between the positive and negative plates. This causes the temperature to rise, leading to a thermal runaway, also referred to 'venting with flame.'   

Lithium-ion cells with cobalt cathodes (same as the recalled laptop batteries) should never rise above 130°C (265°F). At 150°C (302°F) the cell becomes thermally unstable, a condition that can lead to a thermal runaway in which flaming gases are vented.
During a thermal runaway, the high heat of the failing cell can propagate to the next cell, causing it to become thermally unstable as well. In some cases, a chain reaction occurs in which each cell disintegrates at its own timetable. A pack can get destroyed within a few short seconds or linger on for several hours as each cell is consumed one-by-one. To increase safety, packs are fitted with dividers to protect the failing cell from spreading to neighboring cells. 

SAFETY LEVEL OF LITHIUM-ION SYSTEMS
There are two basic types of lithium-ion chemistries: cobalt and manganese (spinel). To achieve maximum runtime, cell phones, digital cameras and laptops use cobalt-based lithium-ion. Manganese is the newer of the two chemistries and offers superior thermal stability. It can sustain temperatures of up to 250°C (482°F) before becoming unstable. In addition, manganese has a very low internal resistance and can deliver high current on demand. Increasingly, these batteries are used for power tools and medical devices. Hybrid and electric vehicles will be next.

The drawback of spinel is lower energy density. Typically, a cell made of a pure manganese cathode provides only about half the capacity of cobalt. Cell phone and laptop users would not be happy if their batteries quit halfway through the expected runtime. To find a workable compromise between high energy density, operational safety and good current delivery, manufacturers of lithium-ion batteries can mix the metals. Typical cathode materials are cobalt, nickel, manganese and iron phosphate. 

The battery manufacturers achieve this high reliability by adding three layers of protection and they are:
[1] limiting the amount of active material to achieve a workable equilibrium of energy density and safety; 
[2] inclusion of various safety mechanisms within the cell; 
[3] the addition of an electronic protection circuit in the battery pack.

We need to keep in mind that these safety precautions are only effective if the mode of operation comes from the outside, such as with an electrical short or a faulty charger. Under normal circumstances, a lithium-ion battery will simply power down when a short circuit occurs.   

If, however, a defect is inherent to the electrochemical cell, such as in contamination caused by microscopic metal particles, this anomaly will go undetected. Nor can the safety circuit stop the disintegration once the cell is in thermal runaway mode. Nothing can stop it once triggered.  

NOTE: A major concern arises if static electricity or a faulty charger has destroyed the battery’s protection circuit. Such damage can permanently fuse the solid-state switches in an ON position without the user knowing. A battery with a faulty protection circuit may function normally but does not provide protection against abuse. 

Another safety issue is cold temperature charging. Consumer grade lithium-ion batteries cannot be charged below 0°C (32°F). Although the packs appear to be charging normally, plating of metallic lithium occurs on the anode while on a sub-freezing charge. The plating is permanent and cannot be removed. If done repeatedly, such damage can compromise the safety of the pack. The battery will become more vulnerable to failure if subjected to impact, crush or high rate charging. 

Asia produces many non-brand replacement batteries that are popular with cell phone users because of low price. Many of these batteries don’t provide the same high safety standard as the main brand equivalent.  

A wise shopper spends a little more and replaces the battery with an approved model. 

To prevent the infiltration of unsafe packs on the market, most manufacturers sell lithium-ion cells only to approved battery pack assemblers. The inclusion of an approved safety circuit is part of the purchasing requirement. This makes it difficult for a hobbyist to purchase single lithium-ion cells off-the-shelf in a store. The hobbyist will have no other choice than to revert to nickel-based batteries. 

I would caution against using an unidentified lithium-ion battery from an Asian source, if such cells is available.

The safety precaution is especially critical on larger batteries, such as laptop packs. The hazard is so much greater than on a small cell phone battery if something goes wrong. For this reason, many laptop manufacturers secure their batteries with a secret code that only the matching computer can access. This prevents non-brand-name batteries from flooding the market. The drawback is a higher price for the replacement battery.