Ampere hours, voltage, Li-Ion, NiCd… all these are terms that you might hear thrown around when you are looking at purchasing a new cordless tool. But what do they all mean? How do you know when the salesperson has no idea what they are talking about and just wants the commission?
Well, let’s give you a bit of an education and go over the different battery types, ratings and everything else you need to know regarding batteries for cordless tools. That way you can be armed with all the info you need to make an informed decision.
If you told a carpenter that you relied on nothing but a battery drill to do all your screwing and drilling jobs 15 years ago, they would have laughed at you. These days, cordless drills, nailguns and other such cordless tools are their most used devices.
Battery technology has improved vastly over the past decade, and in some cases, the tools that they power can perform just as well as a corded tool.
One of the main problems with batteries in the past was their ability to last the distance. There is nothing more annoying than having your battery run out of juice halfway through a job.
Modern-day Li-Ion batteries can provide power for extended periods of time, and also recharge quite quickly – making them a worthwhile investment.
The cordless tool industry has grown exponentially since the release of the Li-ion battery, mainly because of the vast improvement over the other older battery types.
Yes, it is true that some of the other battery types listed in this article are outdated, but they do still have their uses and they are still sold with some cordless tools such as cordless lawn mowers, or grass shears.
The super quick answer: If you want the quick answer as to which battery type is best, then you will probably want to go with a Li-ion battery.
Of course, there are many other things to consider, if you want to learn a bit more then please keep reading.
When you are shopping for a cordless tool, you will notice that you are bombarded with different battery specifications.
While this seems like the obvious answer, it does depend on numerous factors… which we will look at.
Let’s quickly explain some of the most commonly used terms when it comes to cordless tool batteries.
What does Ah mean? What does it mean when the Ah or a battery is (X). These are some of the most common questions we get. And it actually isn’t that complicated.
Ah, or ampere-hour is the total amount of charge your battery can deliver in one hour. E.g. Under ideal conditions, a cordless lawn mower that continuously draws 2.0 amperes (amps) of current will drain the total charge of a 2.0Ah battery in 1 hour.
So by that logic, a 4.0Ah battery should last for 2 hours in the same electric mower. This is all assuming of course that the mower draws a constant 2.0A and that conditions are ideal for the battery – which never happens in the real world.
There is another thing to consider here, and that is the fact that a 4.0Ah battery is not necessarily going to last twice as long as a 2.0Ah battery will. In some circumstances, it may actually last more than twice as long. It all depends on the type of battery, how it is wired up and the control circuitry in the battery itself.
But you can still use the basic reasoning mentioned here to roughly judge how long a battery might last.
So what does Ah mean on a battery? To put it simply, Ah is a measure of how much charge the battery can provide. A simple analogy would be the size of the fuel tank in a car.
The voltage (V) rating of a battery is a measurement of how much power that battery can provide.
To put this in very simple terms, the higher the voltage, the more powerful the battery. Some cordless devices require more power to run, so a cordless drill that is designed to drill through tough timber is going to need more power than a drill that is only designed to do light work.
Yes, higher voltage generally means the tool is more powerful – but it also means more weight in the tool and these higher voltage tools also generally cost a lot more. It all comes down to choosing the right tool for the job, remember that bigger is not always better.
The memory effect occurs when a battery is constantly partly drained, then charged without being allowed to fully discharge. The name comes from the fact that the battery remembers how much of its charge was drained before being charged and then uses the shorter charge period as its new capacity.
Cycle life is a measurement of how many times a battery can be charged before losing the ability to retain energy.
For example, Li-Ion batteries in cordless tools generally have a cycle life of 300-500. So theoretically you could charge a Li-Ion battery at least 300 times before it would need to be replaced.
After a cordless tool battery has been charged, if the battery is not used immediately it starts to slowly lose its charge. Some battery technologies have a much faster self-discharge rate than others.
Keep in mind that a faster self-discharge rate is not always bad – if your tools are never stored away for long periods between use then you probably won’t care about the self-discharge rate at all.
A deep discharge is allowing the battery to completely drain of energy through use. This can be problematic for some battery types (not all) and can severely reduce the batteries cycle life and capacity.
On the flip side, there are some battery types that should periodically be allowed to deep discharge in order to maintain a healthy battery.
Most guides that you read about cordless tools batteries will be focused mainly on Lithium Ion (Li-Ion) and that is with good reason. Li-Ion have become the go-to battery of choice for most cordless tool manufacturers. This is for a few reasons:
Before we go into too much detail, let’s take a quick visual look at the difference between the 4 main battery types.
Well, we have tried to make it simple to compare the different battery types with this handy below.
Maybe – but it does give us a few important insights into the battery types. From this info, we can take the following away:
So the long and the short of it is: A Li-Ion battery is smaller and can provide a lower current for a much longer period than a NiMH battery. But a NiMH battery can deliver high bursts of current when needed.
The Nickel Cadmium battery has a long history, in fact, it was first invented in 1899! Of course, it only started being mass produced in 1946 and it grew in popularity from there. They are generally outperformed by both NiMH and Li-Ion batteries but are still useful for some jobs today.
Brought into mass production in 1989, NiMH batteries are a much newer technology. They are an improvement on NiCd batteries in many ways, the main points being that they are less toxic to our environment when disposed of, and have significantly improved capacity (Ah). They do of course come with some downfalls which can be seen in the following sections.
Cycle life: loses capacity after around 600 cycles, although this can be improved upon if charged and stored correctlySelf-discharge: 13.9–70.6% at room temperatureAh rating: 2.2Ah – 3.0Ah (medium)
If your NiMH batteries have developed a memory effect or capacity has been reduced, then it is likely you can recondition them by following this guide.
Entering commercial production in 1991, the newest technology in batteries for cordless tools is the Lithium-Ion battery (Li-Ion). As far as we are concerned, Li-Ion batteries are the best choice for cordless tools, whether it is a cordless lawn mower or a cordless drill.
Li-Ion batteries do not suffer from a memory effect and they are not affected by poor charging habits. Li-Ion batteries instead wear out over time due to age and use. The main downfall of this type of battery is the relatively short life cycle (<500 charges)
Lead-acid batteries are not commonly thought of when it comes to cordless tools, but they are still quite common in cordless lawn mowers so we have decided to give them a small section in this article.
The lead-acid battery was first put to commercial use in train carriages in 1859, it has obviously had multiple revisions and improvements since then but is still widely used today for a number of applications.
You will typically find these used as cordless lawn mower batteries and batteries for the starter motor in ride-on mowers. This is because these tools have much more room for a larger and heavier battery.
Are Porter Cable and Craftsman Batteries Cross Compatible?
The heading in this section is a common search I found online. It appears so therefore many people are searching for this answer. As with every other manufacturer, the batteries are made for that specific brand and no other.
It’s unfortunate, as an almost daily user of cordless drills, but there are other alternatives, like buying a 2nd or even 3d backup battery.
Sometimes, you can find them used at garage sales or pawn shops. Online at Facebook Marketplace is another good place to find deals on used tools. I sell them there and buy lots of good used tools there.
Can I use a Cordless 40v Battery in a Cordless 20v Tool?
Let’s say you have a Ryobi cordless drill that is supposed to be run on a 20v battery. Now, you just happen to have a 40v battery for your Ryobi cordless circular saw.
Can you use that 40v in the drill? Chances are, if they are from the same series, you will be able to attach the battery to the drill but what will happen?
It is very likely that your drill will not last very long with that much power being offered to it. The 40v battery will probably fry the cordless drill.
So, don’t do it! Instead, get an appropriate battery which, in this example, is a 20v. Sometimes you just need to bite the bullet and buy a new one.
A deep discharge is allowing the battery to completely drain of energy through use. This can be problematic for some battery types (not all) and can severely reduce the batteries cycle life and capacity.
While this seems like the obvious answer, it does depend on numerous factors… which we will look at.
So what does Ah mean on a battery? To put it simply, Ah is a measure of how much charge the battery can provide. A simple analogy would be the size of the fuel tank in a car.
Cycle life is a measurement of how many times a battery can be charged before losing the ability to retain energy.
Brought into mass production in 1989, NiMH batteries are a much newer technology. They are an improvement on NiCd batteries in many ways, the main points being that they are less toxic to our environment when disposed of, and have significantly improved capacity (Ah). They do of course come with some downfalls which can be seen in the following sections.
FAQ
Do any cordless tool batteries interchange?
Are Dewalt batteries interchangeable with other brands?
Are Makita and Dewalt batteries interchangeable?
Are Craftsman and Dewalt 20v batteries interchangeable?
