Now that we’re finally seeing the digital age slide into maturity, the best advice anyone can take to heart is finding the perfect batteries. While disposables remain in existence even today, including the familiar alkaline cells commonly sold by department stores, the reality is these technologies have become outdated and are completely inadequate for meeting the needs of today’s advanced electronics.
With usage patterns forming as they have, and the public’s burgeoning appetite for an ever-increasing ecosystem of gadgets, anyone choosing the route of disposables will, given sufficient time, end up throwing out many tonnes of toxic material over the course of a lifetime, paying tens of thousands of dollars for the privilege.
The good news is, there’s a better way! Several game-changing rechargeable systems have made their way to the forefront and make it possible to not only get superior performance in your devices, but also to do so at an extremely low total cost of ownership.
The Origin of Modern Rechargeables
Batteries have a venerable history, and I recommend reading more on the topic if you have time. In a nutshell, there are two main branches of battery (more properly, cells when referred to in the singular) chemistries in existence today: primary and secondary cells. Primary cells are single-use, and these make up the disposables of yesteryear that most of us are familiar with (dry or ‘heavy duty’ cells, zinc-air, alkaline, and others), while secondary cells are multi-use and can be recharged after each time they’re discharged, sometimes for many thousands of cycles.
As far as giving convenient power to the masses, the battery is an amazing invention, but we are only now beginning to realize its true innovation and convenience thanks to the advent of rechargeables.
The reign of primary cells for the past hundred years has meant the accumulation of immense volumes of manufacturing and handling processes that have proven to be quite wasteful. Production of a typical primary cell requires 150 times the energy contained in that cell by the time it reaches marketable form! The disposal of depleted cells further consumes substantial land and energy assets, creates a huge solid waste stream, occupies a lot of landfill space, and leaches corrosive compounds into the soil after disposable batteries are buried.
The Rise and Fall of Nickel-Cadmium
During the 1980s, the first serious effort was brought to market in an effort to create a solution to the problem of disposable cells. The initial generation of everyday-use rechargeables, nickel-cadmium cells (NiCd), was launched. These achieved a very limited amount of success due equally in part to low consumer brand recognition and inadequate performance in real-world applications. Issues like low storage capacity, a lack of appreciable recycling programs, rapid self-discharge, memory effect, and high materials toxicity served to chip away at the reputation of early NiCds, preventing the product being seen as a viable alternative to the alkaline cell.
Since those days, considerable inroads have been made in terms of recycling and quality control, but modern NiCds still suffer from most of the same problems as their predecessors, those being the high toxicity, low storage capacity, and tendency to self-discharge so quickly as to be useless in standby applications. After being superseded by other emerging technologies, it’s now fairly rare to see NiCds offered on the consumer market at all outside of specific applications (mostly old power tools or solar garden lights).
One might visualize NiCd as the pioneer that took all the arrows in the back, paving the road for modernization of the battery industry and giving us an incentive to seek out cleaner, more practical technologies. Personally, I’m thankful that we’ve seen cell tech evolve so much since then.
Nickel Metal hydride
If you’re on the hunt for a true alkaline cell replacement, this is the technology you need. More commonly written as NiMH, these cells don’t use toxic heavy metals in their manufacture and thanks to recent advances in chemistry and cell structure, their performance has advanced by leaps and bounds over the years, finally making them far superior to any disposable cell technology on the market.
Unlike alkaline cells, whose stored power capacity diminishes steeply as the amount of current (amperage) being drawn rises, NiMH systems are able to maintain a specific reserve energy capacity at all times and feature a relatively flat discharge curve that stays predictable and consistent even at different current levels. What this means for the user is NiMH cells end up running two to ten times longer than alkaline cells of the same size. Because of this ability to deliver a constant voltage and current for long periods of time, they’re ideal for medium or high drain applications including flashlights, shavers, digital cameras, and other complex electronic devices.
In addition to this, the old problem of cells self-discharging when left on the shelf has mostly been solved by a number of advances in cell structure and chemistry. The new generation of low self-discharge (LSD) NiMH cells have the ability to be used as a standby power option much like alkalines are known for. Typically marketed as ‘pre-charged,’ ‘ready to use,’ ‘hybrid,’ or ‘low self discharge,’ LSD NiMHs can be left on the shelf for more than a year without losing much of their stored power.
Charging and maintaining NiMHs has also become an attractive ritual of ownership. This wasn’t the case a decade or even five years ago! Thanks to some truly awesome advances in microprocessor ‘smart’ chargers, which use the cell’s internal resistance and voltage to determine charging needs, it’s now a matter of simply popping the cells into a charger and coming back when it’s convenient. The charger takes care of the rest, from setting the charge current to monitoring battery capacity to automatically turning itself off once the task is finished. Thanks to this, NiMHs can be charged any time a user wishes to top them up, regardless of how much they’ve been discharged. That being said, it’s better to recharge cells before they become completely exhausted, as this helps provide longer service life and more charge cycles over the long run.
General advice on NiMH:
- The charger makes or breaks the user experience, so get the best one you can find and do some research on its specifications before making your purchase.
- The best chargers are microprocessor managed, will have individual cell channels (meaning they can handle one, two, three, or four cells), and should deliver a complete charge within one to three hours.
- The charger specifications should mention ‘delta V’ (voltage change), voltage monitoring, ‘delta T’ (temperature change), or temperature monitoring. Other indicators like LCD readouts or individual progress meters for cells are good tip-offs that you’re looking at a smart charger.
- Never charge at a rate greater than 1C (1x the capacity of the cell in mAH). This shortens cell life and might cause them to poop out prematurely. It also means you’d do well to avoid any product that advertises the ability to charge batteries from 0% to 100% in less than an hour. This technology is evolving, but at the time of this writing it’s not yet fully mature.
- For the best performance, buy only low self-discharge (LSD) NiMH cells. These can be recognized easily from marketing terms like ‘hybrid,’ ‘ready to use,’ ‘pre-charged,’ or ‘low self-discharge.’ If all else fails, check the specs. They should be able to retain at least 80% of their charge after a year on the shelf.
- Charge capacity is measured in milliamp-hours (mAH), or less commonly, amp-hours (AH); one amp-hour is equal to 1000 milliamp-hours. Buy cells rated at 2000 mAH or above.
- Bonus: if your devices use batteries in even numbers, it can help to organize cells into pairs and number each pair with a unique identifier (Set A, Set B, etc.). This assures even wear across their full service life, maximizing performance. Of course, a person can mix and match cells without any issues. This last tip is mostly for people like me, who strive to get the absolute best from their gear.
For several years, I’ve owned the Sanyo Eneloop charger (NC-MQH03U), as well as a combined inventory of 30 AA cells by Sanyo Eneloop and President’s Choice and 24 AAA cells by Sanyo Eneloop and Vivitar. With the exception of the two AAAs I accidentally left outdoors in the rain during my first month in Victoria, all of my stock is working as perfectly as it did on the day I bought it (that’s actually saying a lot, considering some have endured ‑60 Celsius wind chills, blazing desert sun, and extended periods of high ambient moisture, and it just doesn’t faze them). I’m a big proponent of durability and torture tests, so as I’m concerned NiMH has earned its stripes and my recommendation. This is a mature, stable technology that’s already superior to alkaline, and is being improved even more as time goes on. You’ve got nothing to lose (and much to gain) from adding it to your life.
Lithium Ion
If you’ve ever wondered about the magic behind lithium-ion (Li-Ion) batteries, look no further than your mobile phone. Durable, dependable, and capable of holding onto a large amount of energy for a very long time, the Li-Ion cell has become the darling of the IT industry and resides in virtually every mobile device on the market. With a shelf life of well over a year between charges, these cells are ideally suited to high-end electronics, and in this, their wild success has really been a no-brainer.
There are several subcategories and families of Li-Ion that comprise a multitude of form factors and varying battery chemistries, but from the perspective of the end user, they all do roughly the same thing, with a few differences here and there in handling and charge recommendations.
Unlike NiMH and disposable cells, Li-Ion are ridiculously finicky when it comes to their handling needs and charge characteristics. Overcharging or shorting a Li-Ion cell will usually cause it to fail catastrophically, with gas venting or flames. Conversely, if a Li-Ion cell ever becomes fully discharged (deep cycle), it immediately loses the ability to take another charge! Battery manufacturers have long since figured out how to avoid both problems, and all modern battery packs and cells meant for consumer use are shipped with protection circuits that continuously look after battery dynamics and prevent excess charge or discharge.
Unsurprisingly, Li-Ion cells require sophisticated smart chargers due to the complexities of the protection circuitry and the inherently sensitive nature of each cell’s internal components. The Li-Ion charge cycle demands constant voltage and current monitoring, cell response monitoring, and occasionally the need to reset a tripped protection circuit. As noted in the link, there are several phases best shown via graphs in which the charger must be able to measure and respond appropriately to each part of the cell’s natural cycle in order to make it reach full charge.
In terms of their form factor and case design, Li-Ion batteries are often manufactured to fit the physical specifications of the device they’re intended to be used in. This means that you’re not going to find any ‘standard’ sizes that fit all devices. Rather, the ecosystem is fragmented and you’re bound to encounter as many differing shapes and sizes as there are fish in the sea.
Cylindrical Li-Ion cells do exist, and a few are even in circulation that have the same physical dimensions as the more common AA and AAA cells. There’s a catch, however: they run at completely different voltages and have different capacity ratings. While a user might encounter a NiMH AA cell rated for 2000mAH at 1.25 volts, a Li-Ion cell of the same physical size and dimensions would be rated for 750 mAH at 3.7 volts! This is why, if you own any sort of high performance gear that makes use of Li-Ion, you need to verify the delivery voltage before installing the batteries.
Apart from this, there’s also a flourishing community of people worldwide who’ve included cylindrical Li-Ion cells in their day-to-day gadget use in much the same way as others would use AA and AAA cells. In this case, however, the gear is designed to handle the higher voltage and the batteries are most often used for high-drain items like flashlights and bicycle visibility gear. In these environments, the long-term reliability and light weight of the Li-Ion system really stand out. In terms of battery sizes, there are lithium AA (14500) and AAA (10440) cells, as well as the standard 18650 cell, which make up the bulk of these consumer favourites.
General advice on Li-Ion:
- Lithium cells are a specialist device. Make sure you’re using the right tool for the job.
- Get the best charger you can find. For reference, here’s the one I picked out. Because of the way these cells work, having a quality charger on hand is even more important in assuring safety, reliability, and long service life.
- Do your research. Learn about the different chemistries, the ways batteries charge, the algorithms used by chargers, and most importantly, the data posted online by trustworthy reviewers. Sites like Candlepower Forums and Budget Light Forum are a valuable aid, and CPF Marketplace is a great place where the user can get in touch with many of the best manufacturers and distributors.
- NEVER use Li-Ion cells without protection. Unprotected cells are typically sold for use by qualified manufacturers who install them in tool or RC packs which already have some sort of protection built in. Using them in anything else is risky at best because it introduces a chance that the cell will be damaged by improper charging or excessive discharge.
- Buy from reputable vendors. My personal favourites are Solarforce and AW. Investing in quality equipment from the beginning ensure you’ll have a good experience and your equipment will last for may years. Beware of anyone claiming to be offering super-high capacity cells for rock bottom prices, almost invariably it’s a scam where someone has re-packaged dead or recycled components sourced from unscrupulous third parties (this is every bit as dangerous as it sounds).
- Buy about 150% of what you need. Unless you’re preparing for a zombie apocalypse, what’s the joy in owning entire caseloads of cells? Get just a bit more than you need to get the job done.
- Cycle and rest. It’s best to let freshly charged cells sit on the shelf for 12 to 24 hours after they’ve been removed from the charger. This aids stability and helps ensure the longest possible service life. While one cell is resting, you can make use of another that’s finished its rest phase.
For the past few years, I’ve owned a 4Sevens Single Bay V3 charger and a small stock of Solarforce 18650 cells (of which two are the original S18650P and two are the S18650P[V3]). I purchased the charger based on its incredible versatility, compatibility with virtually every battery size/chemistry, well-regarded algorithm, and additional USB and 12V charge options. The cells themselves have been subjected to extreme weather, much the same as I did with the NiMHs.
My original pair of S18650P cells are now two years old, and having taken them through consistent daily use and hundreds of charge cycles in that span of time, I’ve noticed a slight drop in performance (about 15% reduced capacity) due to wear and tear. Other than that, there have been no problems with charging, discharge, or performance, and I feel the technology has had ample time to prove itself. I bought my second pair of 18650 cells this year thinking I’d need replacements by now, but that simply hasn’t been the case. The original two are still going strong.
Apart from this, I took it upon myself to get a pair of AW 14500 cells for my Xeno E03 (a special type of hyper-driven LED flashlight from Hong Kong). These, too, have performed well in regular service.
Looking back, I think that my biggest reason for not jumping into Li-Ion earlier was a lack of information and experience. There have been horror stories circulating in the media about these batteries for years, and sadly what news crews don’t tend to give airtime to is the fact that the accidents and safety concerns in the public consciousness have arisen as the result of counterfeit goods or serious factory defects. Thankfully the rate of defects has been drastically reduced due to stricter quality controls and improved manufacturing processes, but there is still the issue of shady dealers knowingly selling fake, recycled, or defective items to consumers who don’t know enough to guard themselves from it.
So again, follow the tips in this article and learn before you leap.