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Cordless Tools Batteries

9 August, 2023

Cordless Tools Batteries

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In this article we explore the different cordless tools batteries available and explain how selecting the appropriate battery can significantly enhance efficiency in your DIY endeavours.

Choosing the right one is essential for all cordless tools batteries

The first categorisation is related to the different battery chemistries that exist in the market. We have 3 main chemistries available:

  • Lithium-Ion (Li-ion) Batteries: These are the most common choice for cordless tools due to their high energy density. They are lightweight, which helps with use fatigue, and they have minimal self-discharge. The great advantage of these batteries is that they offer consistent power output until they are empty. This means you won’t see any degradation on the tool’s performance during use.
  • Nickel-Cadmium (Ni-Cd) Batteries: These are less common today, but they can still find use in some older cordless tools. They are very durable and perform well under extreme conditions. Their main disadvantages (and the reason why they are no longer as common as Li-ion) is that they suffer from the “memory effect” and they have lower energy density compared to Li-ion batteries, so for the same battery weight you get less power. Ni-Cd batteries require careful charge and discharge cycles, as they need to be removed from the charger once fully charged, instead of being overcharged which may lead to voltage depression.
  • Nickel-Metal Hydride (NiMH) Batteries: These can be classed as the middle spot between Ni-Cd and Li-ion batteries. They have higher energy density than Ni-Cd batteries and suffer less from “memory effect”, but they still have slightly lower capacity than Li-ion batteries.

What should I look for when choosing cordless tools batteries?

As we all want to avoid changing batteries while using a tool, the first thing you should look for in a cordless tool battery is its capacity. This is measured in ampere-hours (Ah) and it determines how long your cordless tool can operate before the battery needing a recharge. The higher the Ah rating is, the longer the battery’s runtime will be. Do keep in mind that often higher Ah ratings mean bigger weight, so if weight is a limiting factor due to physical or location restrictions, you may need to compromise with two batteries of smaller capacity instead of a large one.

One thing to look out for is that you get the correct voltage for your cordless tool. Cordless tools batteries are not all made the same and their voltage ratings typically range between 12V and 36V or higher. It is the tool itself that will determine what voltage battery you should get. Higher voltage batteries generally deliver more power, making them suitable for heavy-duty tools, while lower voltage batteries are lighter and more suitable for light to medium-duty tools. Never ever use higher voltage batteries in your power tools thinking you will make the tool work better, it is guaranteed to be permanently damaged.

The only exception to this rule are batteries which support a variable voltage range, such as the patented FlexVolt series from Dewalt that automatically switches voltages when you change your tool.

Cordless Tools Batteries - Variable Voltage Battery from Dewalt

Cordless Tools Batteries – Variable Voltage Battery from Dewalt

What about fast charging cordless tools batteries?

The convenience of a fast charging battery becomes a necessity when you are limited by a small number of batteries while and a big workload. But unless this is absolutely necessary for you, we recommend you do not use fast charging cordless tools batteries as they deteriorate at a faster rate than batteries that undergo a normal charge cycle.

How can I maximise the efficiency of my cordless tools batteries?

Strange as it may sound, for extended DIY or professional projects it is a great idea to invest in additional batteries to ensure continuous work without interruption. Remember to store your cordless tool batteries in a cool, dry place when not in use. Extreme temperatures can affect battery performance and reduce their lifespan.

In regards to maintenance, make sure you keep your batteries clean and free from debris, and always follow the manufacturer’s guidelines for charging and discharging to maximize battery life.

Unless the power tool requires it specifically, avoid Ni-Cd batteries and prefer Li-ion. They don’t suffer from “memory effect” and you can charge them any time you like. Of course, as with all Li-ion batteries, it is best to keep them charged at a level of no more than 80%, and avoid them being discharged below 20%. In other words, don’t use your batteries till they run out of juice, put them on charge before that. This is why we recommend investing in two batteries instead of just a big one.

Are aftermarket cordless tools batteries good for my tools?

Before we answer this question, let’s clarify something. We are not talking about fake batteries here. We are talking about batteries that clearly say they are aftermarket. The difference is that fakes are sold in slightly lower prices than the originals, but they are advertised as originals. Here’s a video about a fake Makita battery for a power drill:

Aftermarket batteries are third-party, non-OEM (Original Equipment Manufacturer) batteries that are often sold as more affordable alternatives. These are clearly advertised as aftermarket, so there is no disambiguation about pretending they are genuine OEM. Here’s what you need to be aware of:

Pros of aftermarket cordless tools batteries:

  1. Aftermarket batteries are generally more budget-friendly than OEM batteries, making them an attractive option for those looking to save money.
  2. They are also often more readily available, especially for older or less common tool models where OEM batteries might be challenging to find.
  3. Some aftermarket batteries are designed to be compatible with multiple tool brands, providing flexibility and convenience.

Cons of aftermarket cordless tools batteries:

  1. The quality and the chemistry of aftermarket cordless tools batteries can vary significantly. And while some brands do offer reliable products, others may have lower-quality components, resulting in shorter lifespan and reduced performance. A typical example would be a battery of the same capacity and Ah’s, but consisting of Ni-Cd cells instead of Li-ion. This means that, even though the capacity is the same, your battery will carry all the disadvantages Ni-Cd batteries are known for. The price will definitely be more competitive, but it is important to compare batteries like for like.
  2. Warranty concerns also come into play. Some tool manufacturers explicitly state that using aftermarket batteries will void the warranty on their tools. Regardless of whether there is a technical reason behind this or if it’s just their way to promote their own batteries, if any issues arise with the tool while using an aftermarket battery, the manufacturer may not cover the repairs.
  3. In rare cases, low-quality aftermarket batteries may pose safety risks, such as overheating or even causing damage to the tool or injury to the user. Be very cautious with extra cheap batteries, you usually get what you pay.

How do I choose which aftermarket cordless tools battery to buy?

Before anything else, identify the make and model of your cordless tool, as well as the battery’s voltage and capacity requirements. You can find this information on the tool’s nameplate, the user manual or the existing battery itself.

Look for aftermarket batteries on our website or other websites. Ensure that the aftermarket batteries you find are specifically designed for your tool’s make and model. Don’t just judge by the shape as batteries may look the same but have different connectors.

Confirm that their performance specifications are comparable to the original batteries to ensure similar power output and runtime. Pay attention to the battery’s chemistry. Lithium-ion (Li-ion) batteries are generally the preferred choice due to their high energy density and lightweight design, but make sure to choose the right chemistry for your tool if alternatives are available.

The batteries you buy should come with a reasonable warranty period, preferably matching or exceeding the warranty offered by OEM batteries. Ensure the seller has a clear return policy in case of any defects.

When you receive the battery, double check that the voltage is correct before connecting it to the tool, to avoid any issues that could lead to actually damaging the tool irreparably. Also, ensure that the battery charges properly with your existing charger, and make sure you do not leave it unattended until you have confirmed that it doesn’t overheat while charging.