Understanding the Confusing World Of Rechargeable Batteries
Can you imagine life without batteries? The Groom+Style team certainly can’t. However, when our rechargeable batteries don’t work, or last as long as expected, they can have us in tears.
Have no fear, Groom+Style’s rechargeable battery care and user guide will help you understand everything you need to know to:
1. identify what rechargeable batteries are hidden in your cordless appliances and tools
2. choose the best rechargeable battery for the latest cordless appliance or tool you are about to buy (that is when there are various models with different rechargeable battery types available)
3. care and maintain the rechargeable battery in the tools and appliances you already own
Batteries, (Disposable) Batteries, Everywhere!
Just look around the room you’re in right now, and try to guess how many batteries are in use.
Remote controls, phones, laptops, children’s toys, garage door openers – you may even be wearing a battery if you have a wristwatch or Fitbit on.
Some types of batteries have become almost an afterthought. Most of us regularly buy large packs of non-rechargeable AA or AAA batteries because we need so many of them, and the process of swapping them out is almost second nature. Rechargeable AA or AAA batteries, like their cousins C and D, can be handy, but most of us don’t bother with them for ordinary appliances, controls and devices.
On the other hand, we’ve all been ready to scream (or worse) when trying to figure out what type of “non-standard” battery we need to replace the dead one in their automatic car ignition or watch).
Rechargeable Batteries in Our Cordless Appliances and Tools
The rechargeable batteries in our appliances and devices fall into the middle of that spectrum, because we barely even think about them. We don’t have to buy them in bulk, nor do we have to worry about replacing them very often. In fact, we’re more likely to just replace an entire appliance if its battery won’t take a charge anymore. (If you have a problem with the battery in your Tesla or Nissan Leaf, though, we wouldn’t suggest dumping the car.)
The Convenience of Cordless Appliances Outweighs Corded Devices
The fantasy of settling for only corded appliances and devices may cross our minds – briefly.
The convenience of being able to take our devices almost anywhere, particularly in these days of nearly-universal wireless connections, far outweighs the temptation of forgetting about batteries forever. Sure, corded models might be a bit more reliable and powerful, but we’ve become a mobile society accustomed to our comfort while on the go. And that means batteries, not cords. (We’ve also never seen a plug-in remote control, either.)
You want the battery to work for a respectable period of time and then recharge properly. It’s highly unlikely that you even consider what type of rechargeable battery is inside.
But you should.
There are Five Main Types of Rechargeable Batteries
1. Lead-Acid Rechargeable Batteries
Surprisingly, rechargeable batteries (sometimes called secondary batteries) have been around since 1859. That’s when a French scientist invented the lead-acid battery which uses sulfuric acid to create chemical reactions. It’s still used today in the majority of automobiles as well as larger vehicles like RVs and smaller ones like golf carts. There may even be one in the UPS for your computer.
Lead-acid batteries are typically large and heavy and they’re able to deliver a big jolt of power immediately, reasons why they’re still a good choice for cars (which need that jolt when you turn the ignition) but a horrendous choice for a hand-held appliance.
They’re also easy to manufacture, reliable, and inexpensive to manufacture and purchase.
However, lead-acid batteries will corrode over time, are bad for the environment and require long recharging periods – that’s why, if you have to jump your car due to a drained battery, you have to drive around for several hours to recharge the battery.
You won’t see lead-acid batteries when shopping for smaller appliances or on the shelf of your local drugstore. It’s easy to see why.
2. Nickel-Cadmium Rechargeable Batteries
This was the rechargeable battery of choice for nearly a century (yes, it was also invented in the 1800s) for most uses. Until the 1990s, the rechargeable battery built into nearly all non-vehicle appliances was a NiCad (also abbreviated as NiCd).
NiCad batteries share one major advantage with lead-acid ones: they can deliver a quick blast of energy. However, there’s a laundry list of disadvantages. They have a very low storage capacity, they don’t deliver higher voltages consistently (for example, something as simple as a flashlight will be dimmer when using NiCads), they discharge quickly and need very frequent charges, and their ability to hold a charge is compromised if you run the battery all the way down or overcharge it.
Nickel-Cadmium batteries, as you’d expect from their name, contain the toxic substance cadmium. For that reason they must be discarded at a hazardous materials facility, and they have been banned by the EU for most uses.
They’re not commonly used in new products anymore, but if you have a very old rechargeable appliance in your house the chances are good that it has a NiCad battery inside.
3. Rechargeable Alkaline Batteries
You don’t see these often, but they were a breakthrough a couple of decades ago when rechargeable alkalines briefly challenged NiCads for market dominance. They’re basically the same as the ordinary D, C and AA alkaline batteries you use once and throw out, but are designed to allow a “reverse” chemical reaction so the charge can be back up. They also are built to prevent hydrogen and pressure from dangerous buildups during the process.
Rechargeable alkalines hold their charge well during long periods when they’re not in use and they provide higher voltages than NiCads (enough to fully power the flashlight we mentioned a moment ago). However, each time they’re recharged they lose some of their native capacity and power, they take a long time to recharge in the special charger required, and they don’t give the strong initial jolt that a NiCad can provide. They also are prone to leaking, just like non-rechargeable alkalines.
Fortunately, a much better alternative to NiCads and rechargeable alkalines was developed shortly before the turn of the 21st century.
4. Nickel-Metal Hydride Rechargeable Batteries
Precursors of Nickel-Metal Hydride (NiMH) batteries were invented in the 1960s, but they were too expensive and not stable enough for widespread use. The technology was finally ready for the consumer market in 1989; improvements continued throughout the 1990s, and by the early 2000s NiMH had replaced NiCad and rechargeable alkaline as the standard rechargeable battery for most purposes.
NiMH batteries have three times the capacity of NiCad, and unlike alkaline rechargeables they’re great at handling “high-drain” devices (like digital cameras) that need quick shots of power. They also don’t contain any toxic materials.
NiMH isn’t a perfect technology. The voltage is lower than alkalines (so our theoretical flashlight will be a bit dimmer) but many appliances and devices are now designed to work with lower-voltage batteries, so this isn’t a major issue. After 100-150 charges they’ll start to lose their capacity, and overcharging can reduce their overall life.
Finally, NiMH batteries don’t hold their charges well when left unused, losing as much as five percent of their power each day and as much as 50% in a month. If that could be an issue for you, look for “low self-discharge” (LSD) NiMHs with slightly lesser capacity.
Even though it’s not the newest type of rechargeable battery, Nickel-Metal Hydride remains a popular choice for devices that consume lots of power in bursts like handheld games, digital cameras and music players.
5. Lithium-Ion Rechargeable Batteries
Experimentation with and use of lithium batteries began in the 1970s, but it wasn’t until the turn of the century that lithium-ion (Li-ion) battery technology was reliable enough for widespread adoption. And Li-ion was indeed adopted quickly, becoming the top choice for powering everything from electronics like laptops and smartphones, to appliances like vacuums and tools like tree trimmers and snowblowers. Li-ion batteries are even used extensively by the military and NASA.
Lots of Key Advantages to Lithium-Ion Batteries
It’s easy to see why lithium-ion batteries are so widely used. They’re much smaller and lighter than NiMH batteries, they recharge about 75% faster and their self-discharge rate is much lower, they are less sensitive to high and low temperatures, and they deliver twice the voltage as any other common type of rechargeable battery.
They’re also the least prone to the so-called “memory effect.” That’s the supposed tendency of a battery to lose capacity when it’s not completely discharged before being recharged – the battery supposedly “remembers” the shorter charge cycle and will no longer charge all the way.
Some Disadvantages to Lithium-Ion Batteries
Of course, there are also drawbacks.
There’s a fixed shelf life; in other words, a Li-ion battery will only last a few years even if you’ve never used it. They’re more expensive than their NiMH counterparts. And to be honest, they don’t really have NiMH “counterparts” because Li-ion batteries aren’t manufactured in standard sizes. You can’t get a AA or D-size Li-ion battery, for example, since they take many different shapes and are only “included” in manufactured products.
You may have expected to hear one other drawback: they can explode. In reality, those highly-publicized occurrences aren’t problems with lithium-ion batteries – they’re problems with poorly-manufactured lithium-ion batteries. If you’re careful to buy only name-brand products, chances are extremely slim that you’ll have an issue with their Li-ion batteries.
Why the Type of Rechargeable Battery Matters – And How to Choose the Correct Type
Understanding the Pros and Cons of Different Rechargeable Batteries Will Help You Choose the Best Battery for Your Device
You wouldn’t use a pair of scissors to cut down a tree, and you wouldn’t use a moving van to deliver a pie. Similarly, there’s a proper use for each type of battery on the market, and it makes no sense to choose the wrong battery for your equipment and the way you use it.
There’s a catch, though. Many devices and tools come with pre-installed rechargeable batteries, meaning you don’t get to choose the battery that’s inside. You may, however, be able to choose between models using different types of batteries.
For example, you might be considering one vacuum powered by a NiMH battery and another that uses a Li-ion. In that case, it’s important to factor the battery’s pros and cons into your overall buying decision.
We’ve dealt with those advantages and disadvantages while discussing each type of battery, but here’s a “cheat sheet” to help you choose the right rechargeable battery. The first choice in each category is the best performer for that category.
|Availability in “standard sizes” like AA||NiMH||NiCad|
|High-drain devices (like digital cameras)||NiMH||Li-ion|
|Low-drain devices (like remote controls)||NiMH (LSD only)||non-rechargeable alkaline|
|Long shelf life||Li-ion||NiMH (LSD only)|
|Long battery life||Li-ion||NiMH|
|No “memory” effect||Li-ion|
|Withstand temperature extremes||Lead-acid||NiCad and Li-ion|
|Shortest charge times||Li-ion||NiCad and NiMH|
And here’s a look at the most common uses for each type of battery. For a more detailed list see the table at the bottom of this article.
– Lead-acid: Cars, small vehicles, industrial equipment
– NiCad: Power tools, emergency lighting
– NiMH: Digital cameras, toys
– Li-ion: Phones, laptops, tablets, electric shavers, trimmers
Care and Feeding of Rechargeable Batteries
The differences between types of rechargeable batteries mean they should be cared for in different ways.
Care and Maintenance of Lead-acid Batteries
There are two types of rechargeable lead-acid batteries, “starting” batteries (as in cars) and “deep cycle” batteries (as in golf carts), and their maintenance requirements are more detailed than we have space for here.
But generally speaking, lead-acid batteries and their connections should be kept clean and the cables should be tightened periodically, with silicone sealer on the post and grease on the washer to help prevent corrosion. If the battery is serviceable, water levels should be checked and refilled regularly; distilled water is best.
Care and Recharging of Nickel-Cadmium (NiCad)
– Charge should be completely used before recharging, to avoid “memory effect”
– Completely drain batteries before storing
Care and Recharging of Nickel-Metal Hydride (NiMH)
– Can be recharged at any time, but should be “conditioned” (fully drain and then recharge battery) after each ten charging cycles.
– Completely charge battery before storing, and recharge every 1-2 months if unused
Care and Recharging of Lithium-ion (Li-ion)
– Can be recharged at any time, but should be recharged often regardless of use
– Battery should not be allowed to fully drain, and it’s best to recharge when 50% of capacity still remains; more frequent charges prolong battery life
– Store in cool area, with battery no lower than 50% capacity
General Rules for Charging Rechargeable Batteries
Battery charging should always be done at room temperature, with a charger designed for the specific type of battery. Otherwise, overcharging can damage or destroy the battery.
It’s probably not necessary to say that batteries shouldn’t be stored in areas where they might be exposed to extreme temperatures, or where they can come in contact with metal objects – but we just said it anyway. It’s also advisable to take batteries off a charger once they’re completely charged. Even if you’re using a smart charger, batteries should always be removed after 24 hours.
It might be a bit of a pain to remember all of that – or even to check to see what type of battery is in your appliance or device – but just remind yourself that it’s a much bigger pain to have to replace a battery after it’s died at the worst possible time because of improper maintenance.
See below a table of some key products and (all things being equal) the optimum rechargeable battery type.
Optimal Rechargeable Battery Type
|travel shaver||AA Batteries or lithium-ion|
|nose trimmers||AA Batteries|
|Electric lawnmowers||lithium-ion (a few cheaper models have lead acid)|
|robot lawnmowers||lithium-ion (less ideal is NiMH)|
|weed eater||lithium-ion (a few cheaper models have NiMH or NiCad)|
|chainsaw||lithium ion (a few cheaper models have NiMH or NiCad)|
|cordless stick vacuums||lithium-ion (a few cheaper models have NiMH)|
|handheld vacuums||lithium-ion (a few cheaper models have lead acid)|
|electric toothbrush||NiMH (a few cheaper models have lithium-ion)|