Hercules and DeWalt batteries are not compatible with each other

Hercules batteries will not fit into DeWalt tools, and DeWalt batteries will not fit into Hercules tools. The two brands use different battery connectors — the metal contacts and physical shape that lock a battery into a tool. Even if you could force a Hercules battery into a DeWalt tool, it would not work and could damage both the battery and the tool.

This incompatibility exists because each brand designs its own battery platform. DeWalt owns its 20V and 60V systems. Hercules (which is owned by Harbor Freight) makes its own 20V system with a different connector design. The voltage may be the same, but the physical and electrical interface is not.

If you own both DeWalt and Hercules tools, you will need to keep separate batteries for each brand. There is no adapter or workaround that safely bridges the two systems.

Key Takeaways

  • Hercules and DeWalt use completely different battery connectors, so batteries from one brand will not physically fit the other.
  • Both brands make 20V systems, but the internal wiring and connector design are incompatible.
  • Forcing a battery from one brand into a tool from the other can damage the tool, the battery, or both.
  • If you use both brands, you must buy and maintain separate battery sets for each one.

Why battery connectors are brand-specific

Each tool manufacturer designs its battery connector to work only with its own tools. This is partly a business decision — it locks customers into buying batteries from the same brand — but it is also a safety measure. A battery connector carries electrical current, and if the wrong voltage or amperage reaches a tool, it can overheat the motor, damage the circuit board, or start a fire.

DeWalt's 20V batteries use a connector with three contact points arranged in a specific pattern. Hercules 20V batteries use a different three-point pattern. The tools themselves are wired to expect current from their own connector shape, and plugging in a different connector can cause a short circuit or send power to the wrong part of the tool.

This is why you should never try to modify a battery or connector to make it fit. Even if you could physically make it work, the electrical mismatch could cause injury or fire.

What to do if you have both DeWalt and Hercules tools

If you own tools from both brands, the most practical approach is to buy a small battery and charger set for whichever brand you use less often. Hercules batteries and chargers are generally less expensive than DeWalt equivalents, so many people choose to buy Hercules batteries if they already own DeWalt tools and only need Hercules for occasional jobs.

Keep the two battery sets in separate locations or clearly labeled so you do not accidentally grab the wrong one. Some people use a small toolbox or bag for each brand to avoid confusion.

If you are considering buying new tools and want to stick with one battery system, choose the brand you will use most often. You can always add tools from the other brand later and buy a small battery set just for those tools.

Can you use an adapter to make batteries compatible?

No adapter exists that safely converts a Hercules battery to work in a DeWalt tool or vice versa. Some third-party sellers online claim to sell "universal" adapters, but these are not safe and do not work reliably. An adapter cannot change the internal wiring of the battery or the tool, so even if it physically connected the two, the electrical systems would still be mismatched.

If you see an adapter for sale, do not buy it. The risk of damaging your tools, starting a fire, or injuring yourself is not worth the small amount of money you might save.

DeWalt battery compatibility within the DeWalt line

While Hercules and DeWalt are not compatible with each other, it is worth knowing that DeWalt batteries are compatible across most DeWalt 20V tools. A DeWalt 20V battery will work in any DeWalt 20V tool — drill, saw, light, or anything else in that line. DeWalt also makes 60V batteries for larger tools, and those work in all DeWalt 60V tools.

The one exception is older DeWalt tools made before the 20V system became standard. If you have a very old DeWalt tool, check the battery connector before assuming a newer battery will fit.

Hercules battery compatibility within the Hercules line

Hercules batteries work across the Hercules 20V tool line in the same way. A Hercules 20V battery will power any Hercules 20V tool. Hercules also makes a 40V system for larger tools, and those batteries work in all Hercules 40V tools.

If you are building a collection of Hercules tools, buying one or two batteries and a charger is enough — you can use the same batteries in multiple tools as long as they are all in the same voltage class (20V or 40V).

What happens if you try to force the wrong battery into a tool

If you try to push a Hercules battery into a DeWalt tool (or the reverse), one of several things can happen. Most likely, the battery straightforward will not fit — the connector is shaped differently and will not align with the slot. If you force it hard enough, you can break the connector on the battery, the tool, or both, and then neither will work.

If somehow the battery did make contact with the wrong connector, the electrical mismatch could cause the tool's circuit board to fail, the battery to overheat, or both. This is a fire risk and a shock risk. Do not attempt this.

Frequently Asked Questions

Can I use a DeWalt charger to charge a Hercules battery?

No. DeWalt chargers are designed to recognize and charge only DeWalt batteries. A Hercules battery plugged into a DeWalt charger will not charge and may damage the charger. Always use the charger that came with your battery brand.

Are Hercules and DeWalt owned by the same company?

No. DeWalt is owned by Stanley Black & Decker. Hercules is owned by Harbor Freight Tools. They are separate companies with separate battery systems.

If I buy a DeWalt tool, can I use it with an old Hercules battery I have?

No. The battery will not fit the tool, and even if it did, the electrical systems are incompatible. You would need to buy a DeWalt battery to use with a DeWalt tool.

What should I do with old batteries from one brand if I switch to another?

Store them safely in a cool, dry place, or take them to a battery recycling center. Many hardware stores and tool retailers accept old batteries for recycling. Do not throw them in the trash — batteries contain materials that need proper disposal.

Is one brand's battery better than the other?

Both DeWalt and Hercules make reliable batteries. DeWalt batteries tend to cost more and may last slightly longer in heavy use. Hercules batteries are less expensive and work well for occasional or moderate use. The best choice depends on your budget and how often you use the tools.