DeWalt 20V to Hercules 20V Battery Adapter (with BMS, Vacuum Pump Compatible)
Sale price
$35.99
Regular price $36.99
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DeWalt 20V to Hercules 20V Battery Adapter (with BMS, Vacuum Pump Compatible)
Sale price
$35.99
Regular price $36.99
Taxes included.
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Safety feature
Built-in BMS Protection
Integrated Battery Management System (BMS) helps prevent battery over-discharge and improves safety.
Use your DeWalt 20V MAX batteries on Hercules 20V cordless tools, without buying into a second battery platform. Both platforms are rated 20V, so torque and speed on the Hercules 20V tool stay where they should be. The molded ABS housing keeps it light and hard-wearing, and pure copper contacts keep current delivery steady. Fewer battery systems in the workshop, on the bench or in the van, and no extra chargers to find room for. It also carries battery protection electronics (BMS) inside.
See it in action
Specifications
- SKU
- PTA-DWM20-HER20
- Fits this battery
- DeWalt 20V MAX (Lithium-Ion)
- Battery voltage
- 20V
- Runs these tools
- Hercules 20V (Lithium-Ion)from Harbor Freight
- Tool voltage
- 20V
- Housing
- ABS (Injected)
- Terminals
- Copper
- Current rating
- 40A continuous (80A peak at 18VDC for up to 2 seconds)720 Watt continuous at 18V nominal
- Internal wiring
- 5 mm²
- Weight
- 128 g (4.5 oz / 0.28 lb)
- Colour
- Yellow
- Operating humidity
- 5–95% RH
- Operating temperature
- -10 °C to 50 °C (14 °F to 122 °F)
- USB port
- No
- Built-in BMS protection
- Yes
- What's in the box
- Battery Adapter
- Warranty
- 12 months after the date of deliveryMore details
- Revision
- Revision 01 (released on March 10, 2025)
Why choose this adapter
- Your DeWalt 20V MAX battery and Hercules 20V tools run at the same voltage, so the adapter changes the fitting rather than converting anything.
- A Battery Management System inside the adapter cuts power before the battery is drained too far — protection your battery may not have on its own.
- Injection-moulded ABS, not 3D printed — no layer lines to split under load.
- Solid copper terminals, so less of the current is lost as heat.
- 5 mm² internal wiring, rated for 40A continuous with 80A peak at 18VDC for up to 2 seconds, so a high-draw tool is not held back by the adapter.
- Covered by a 12-month warranty from the day it arrives.
DeWalt 20V MAX and Hercules 20V compatibility
It works in one direction only: DeWalt batteries powering Hercules tools. For the opposite pairing, see adapters that run on Hercules 20V batteries.
Compatibility can vary with the exact battery and tool model. Before ordering, confirm that your battery belongs to the DeWalt 20V MAX platform and that your tool takes Hercules 20V batteries.
Important charging and safety information
This adapter is for powering cordless tools and nothing else. It cannot charge DeWalt or Hercules batteries and must never be connected to a charger of any kind. Always take the battery out of the adapter before charging, and charge it on the original charger made for your DeWalt 20V MAX battery.
How it works
-
1. Use the battery you own
Any compatible DeWalt 20V MAX battery you already have.
-
2. Slide on the adapter
It goes where the original Hercules 20V battery sits.
-
3. Click in and work
No tools, no wiring, no modifications.
DeWalt 20V MAX to Hercules 20V — Common Questions
My battery says 20V. Can it run a tool rated differently?
Yes, and they are closer than the labels suggest. 20V is what a DeWalt 20V MAX battery measures off the charger with no load; 18 V is what it holds in use. Hercules 20V tools are built around 18 V. The two numbers describe the same class of battery, which is why the adapter works rather than merely fits.
Will this fit my other DeWalt batteries?
Only DeWalt 20V MAX batteries. DeWalt also sells DeWalt 12V MAX, DeWalt 18V Ni-Cd, and those use a different socket — same brand, different rail and contacts, so they need their own adapter. Compare the rail on your battery with the photos before ordering.
Will my Hercules 20V tool run as long on a DeWalt 20V MAX battery?
Runtime comes from the battery, not the adapter — a 5.0Ah DeWalt 20V MAX battery lasts roughly twice as long as a 2.5Ah one, exactly as it would on its own tool. The adapter’s copper terminals and heavy-gauge wiring are there to keep resistive loss low.
Could this damage my DeWalt 20V MAX battery or my Hercules 20V tool?
Used with undamaged, compatible equipment it is not expected to. This adapter has its own Battery Management System, which cuts power before the battery is drained too far, so it protects the battery even where the battery has no protection of its own. Stop using it if the adapter becomes unusually hot, the contacts look damaged, or the tool behaves oddly.
Can I charge through the adapter?
No, and it should never be attempted. The adapter carries power one way only, out to the Hercules 20V tool — there is no charging circuit inside it. Connecting it to a charger puts the battery, the charger and the adapter at risk. Always take the DeWalt 20V MAX battery off the adapter and charge it on its own charger.
My Hercules 20V gear came from Harbor Freight. Is that the same platform?
Yes — Harbor Freight is where Hercules 20V is sold, so a battery or tool bought there is the platform this adapter is built for. What matters is the socket, and Harbor Freight stock is the reference for it.
Does it work with third-party DeWalt batteries?
Usually. What matters is the socket, not the badge: if the battery slides on and locks the way an original does, the adapter takes it and the Hercules 20V tool runs. Aftermarket moulding does vary, so if yours looks unusual send us a photo and we will check before you order.
How much does it add to the Hercules 20V tool?
128 g (4.5 oz) and a short extension between battery and tool. You notice it overhead or in a tight cabinet; on a drill or driver held normally it disappears.