Black and Decker 36V/40V to Black and Decker 20V Battery Adapter
$37.99
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Black and Decker 36V/40V to Black and Decker 20V Battery Adapter
$37.99
Taxes included.
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Use your Black and Decker 36V/40V MAX batteries on Black and Decker 20V cordless tools, without buying into a second battery platform. The battery sits above the tool’s platform — 40V against 20V — so this adapter converts instead of connecting the two directly. Constructed from durable molded ABS with pure copper contacts, for a secure fit and dependable current transfer. This helps you get the most out of your existing battery system while avoiding the cost of another set of batteries and chargers.
Specifications
- SKU
- PTA-BLA40-BLA20
- Fits this battery
- Black and Decker 36V/40V MAX (Lithium-Ion)
- Battery voltage
- 36V/40V
- Runs these tools
- Black and Decker 20V (Lithium-Ion)
- Tool voltage
- 20V
- Housing
- ABS (Injected)
- DC-DC converter
- Yes — 36V/40V to 20V
- Terminals
- Copper
- Current rating
- 60A continuous (100A peak at 18VDC for up to 2 seconds)1080 Watt continuous at 18V nominal
- Internal wiring
- 6 mm²
- Weight
- 148 g (5.2 oz / 0.33 lb)
- Colour
- Black
- Operating humidity
- 5–95% RH
- Operating temperature
- -10 °C to 50 °C (14 °F to 122 °F)
- USB port
- No
- What's in the box
- Battery Adapter
- Warranty
- 12 months after the date of deliveryMore details
- Revision
- Revision 01 (released on August 9, 2026)
Why choose this adapter
- 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.
- 6 mm² internal wiring, rated for 60A continuous with 100A 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.
Black and Decker 36V/40V MAX and Black and Decker 20V compatibility
It works in one direction only: Black and Decker batteries powering Black and Decker tools. For the opposite pairing, see adapters that run on Black and Decker 20V batteries.
Compatibility can vary with the exact battery and tool model. Before ordering, confirm that your battery belongs to the Black and Decker 36V/40V MAX platform and that your tool takes Black and Decker 20V batteries.
Important charging and safety information
This adapter is for powering cordless tools and nothing else. It cannot charge Black and Decker or Black and Decker 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 Black and Decker 36V/40V MAX battery.
How it works
-
1. Use the battery you own
Any compatible Black and Decker 36V/40V MAX battery you already have.
-
2. Slide on the adapter
It goes where the original Black and Decker 20V battery sits.
-
3. Click in and work
No tools, no wiring, no modifications.
Black and Decker 36V/40V MAX to Black and Decker 20V — Common Questions
My battery says 40V. Can it run a tool rated differently?
Yes, and they are closer than the labels suggest. 40V is what a Black and Decker 36V/40V MAX battery measures off the charger with no load; 36V is what it holds in use. Black and Decker 20V tools are built around 18V. The two numbers describe the same class of battery, which is why the adapter works rather than merely fits.
Will this fit my other Black and Decker batteries?
Only Black and Decker 36V/40V MAX batteries. Black and Decker also sells Black and Decker 18V Ni-Cd, Black and Decker 20V, 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 Black and Decker 20V tool run as long on a Black and Decker 36V/40V MAX battery?
Runtime comes from the battery, not the adapter — a 5.0Ah Black and Decker 36V/40V 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 Black and Decker 36V/40V MAX battery or my Black and Decker 20V tool?
Used with undamaged, compatible equipment it is not expected to. Black and Decker 36V/40V MAX batteries are lithium-ion with a protection circuit built into the battery, and it keeps working through the adapter — it stays in the battery and never moves into the adapter. Stop when the tool slows noticeably rather than running the battery flat, and stop using the adapter if it becomes unusually hot or the contacts look damaged.
Can I charge through the adapter?
No, and it should never be attempted. The adapter carries power one way only, out to the Black and Decker 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 Black and Decker 36V/40V MAX battery off the adapter and charge it on its own charger.
Does it work with third-party Black and Decker 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 Black and Decker 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 Black and Decker 20V tool?
148 g (5.2 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.