How Often Should You Change Your Battery in Battery Powered Tools?

How Often Should You Change Your Battery in Battery Powered Tools

The era of lithium-ion batteries is here, and there’s no replacement in sight.

We use them in our phones, our laptops, and even our little micro bluetooth speakers—they’re everywhere, and as helpful as the day is long.

But just like your phone battery, power tools batteries will die and need to be replaced. They’re not going to last forever.

If you want to get the most out of your battery life and truly push the limits of your power tools, then this is what you need to know.

What is the Average Lifetime of Power Tool Batteries?

cordless drill with matching battery

About 300 to 500 cycles, or uses.

If you’ve had the same phone for more than two years and you charge it every day, you might be thinking “I know that these batteries last longer than that.” Well, they do, but they lose efficiency.

The average lifespan of a power tool battery is different from your phone or bluetooth speaker, because you don’t have the ability to put them through a full power cycle like you do with other items.

Power tool batteries are built tough, but manufacturers can only use the most modern methods of lithium-ion battery designs, because that’s the very best option that is available. They need to keep things cheap while also making sure you can recharge your batteries for years to come.

Power tool batteries that have a  one-hour use on full charge will eventually lose that charge at fifty minutes, then forty-five. While this decline is rapid (when it happens), it also isn’t the end of the world.

You can still get some use out of your batteries, and if you have the option, this is the time to start power cycling them.

To do this effectively, you need to drain it entirely. Just bring a backup battery with you and drain your primary battery completely, then run that empty battery through a full cycle to rejuvenate it.

How to Prolong Your Battery Life

man drills wood with cordless drill

While it may sound crazy, one of the best things you can do to keep your lithium-ion batteries intact is by storing them in the right temperatures.

Between that, power cycling, and keeping an eye on the charge, you can extend your battery life. Let’s take a deep dive into each method.

Power Cycling

Let the battery drain entirely, then charge it to 100%—sounds simple enough, right?

If only.

Some batteries, such as polymer lithium-ion batteries, actually respond better if you charge them from 0% up to about 85% or so, and then unplug them there, or if you only use 30% of the overall capacity before you recharge them.

I won’t bore you with the details, but the inside of a lithium-ion battery is extensive, and as a result the working parts end up getting a bit complicated.

Temperature Control

The cold kills your battery. High temperatures, such as from overcharging, will also do a number on your battery life, but you don’t want to charge them in a really cold environment like your garage.

If you live up north and you want to keep your batteries working well, you need to bring them in the house and plug them in near the kitchen or living room where you know what the temperature is going to be.

Overcharging

overcharged battery

It’s a thing. If you plug your lithium-ion battery into an adapter, then you let it hit 100%, you’re supposed to pull the plug right then and there.

Do not let it sit with the power flooding into it and the battery completely full. This can not only raise the temperature of the battery and lead to a potential fire hazard (though many manufacturers are aware of this and take preventative measures, just as a heads up), but it also stresses out the battery.

High Charge Currents

Speaking of stressing out the battery, one final nugget of information is to use low currents to recharge your lithium-ion batteries, even though it will definitely mean longer wait times for a full charge.

When Should You Replace Your Battery?

used batteries

You’re going to see different sides on this, but traditionally, you want to get rid of your battery by recycling it by the time it hits 80% efficiency.

That means that if you used to get five hours of a full charge from a lithium-ion battery, and now you’re only getting four hours, that it’s time to put it out to pasture.

However, there’s also the saying “If it isn’t broken, don’t fix it.” You can still enjoy a battery at 80% capacity, or 70% capacity for that matter, but it becomes less efficient.

Its efficiency rating also declines at a faster pace. It’s like something rolling downhill: once it starts it doesn’t stop, and it gains momentum as it goes.

Lithium-ion batteries, which are common in all power tools that we use every single day, generally have between 300 and 500 full uses. That number is broad, because not enough people go through full power cycles, especially with tools.

For a full power cycle, you should let it drain until it’s completely empty. Then you should plug it in, and not touch it until it’s at 100%. That’s how a power cycle works. Do this repeatedly, and you might get 500 uses out of your lithium-ion battery before it starts to fade./

With tools, this is exceptionally difficult because you’re not going to a) run a drill until the battery dies out if you don’t need to use it anymore, and b) risk running out of battery in the middle of a job. It’s just not practical.

So tool batteries end up running low on efficiency around that 300 usage mark, which is when you’ll want to look at replacing them. It’s important to time them as best you can so you know when the efficiency falls.

You’ll also notice it if you’re just using it and notice it’s dying faster than it used to.

How Many Batteries Should You Have?

six batteries for power tools

This is where things get tricky.

We know how long most lithium-ion batteries last, and that regardless of what brand of battery you get, some cannot really guarantee longevity over others (it’s just the way lithium-ion works). It’s not always clear how many you should get, because there are so many variables at work.

Consider some of these options and uses to determine how many batteries you should get.

  • Do you use your battery-powered tools on a daily basis (such as for work)? If so, they’re going to be put through the wringer, day in and day out. You will need additional batteries handy just to switch out when your current one dies.
  • How long is the battery life? Because you’ll likely be purchasing the new battery from the power tool manufacturer, since they always make the connection points odd so you have to buy from them, you’re going to be met with a harsh reality: brand reliability. Some brands just make better 20V batteries than the next guy, even if it’s all the same voltage and mAh storage capabilities.
  • How many charges is the battery rated for? While you’re going to see a lot of 300-500 uses pedaled by manufacturers, is that really enough for you? Do you find yourself constantly going through them and putting them down to recharge? While full cycling can help with this, sometimes the battery just isn’t up to snuff.
  • Do you have access to reliable charging? If not, you’re going to need more than just one battery: you’ll have to plan for the worst. If you’re working a construction job and need your drill or sawzall, then you’re going to need to have extras handy. If you do a lot of construction and renovation, you might sometimes be working off of generators and be in buildings with no power, so spare batteries are a must.

What do you think?

After all the different ways that you could run out of energy in the middle of a project, you need to really account for every possible scenario where it would be devastating to run out of power.

Know your batteries, keep an eye on their lifespan, and keep them charged; however many you end up with.

Always be Powered Up

Your lithium-ion batteries aren’t going to just die out on you for no reason, but depending on how much use you get out of your power tools (and how long you allow the batteries to sit there for), you can run through them quicker than most people.

It’s all about your usage and some perspective, just know that they don’t last forever.

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