Can Power Tool Batteries with Matching Connectors Be Used Interchangeably?

When it comes to power tool batteries, one question seems to come up a lot: if two batteries have the same connector, does that mean they’re interchangeable? On the surface, this might seem like an easy “yes,” but the answer is a bit more complicated. Let’s break it down.

At first glance, matching connectors might feel like a green light. If the battery fits, it should work, right? Well, not so fast. Most power tool brands have proprietary connector designs—protected by patents, no less. This means that even if two batteries look similar, they might not work the same way. Brands deliberately design their systems to lock you into their ecosystem, so cross-brand compatibility is a rare find.

But even within the same brand, there’s more to consider than just the physical fit. Voltage is a big one. A battery with too high a voltage could damage your tool, while one with too low a voltage might not power it properly. Then there’s capacity—this affects how long the battery will last on a single charge. While a higher-capacity battery sounds great, it might also make the tool heavier and harder to handle. Lastly, internal resistance and safety features also play a role. The wrong battery could overheat, short out, or even ruin your tool altogether.

That said, there’s a workaround if you’re hoping to mix and match brands: battery adapters. These clever little devices let you connect a battery from one brand to a tool from another. For example, a DW18ML battery adapter allows you to use Milwaukee 18V batteries with DeWalt 18V tools. This kind of versatility can save money and reduce the number of batteries you need to manage. However, battery adapters aren’t a magic solution for every situation—availability is limited, and not every combination has an adapter on the market.

Some brands are starting to experiment with cross-brand compatibility through partnerships. Systems like the Cordless Alliance System (CAS) allow tools from multiple manufacturers to share a single battery platform. This kind of collaboration is still pretty rare, but it’s a promising step toward making power tool batteries less brand-dependent.

In the end, while having matching connectors is a good start, it’s not the whole story. Voltage, capacity, safety, and even brand-specific design choices all matter when it comes to compatibility. Adapters offer a practical solution in some cases, but they aren’t universal. By paying attention to the details, you can make better decisions and get the most out of your tools and batteries.