Are Hart and DeWalt Batteries Interchangeable? (No, Here’s Why)

Hart and DeWalt 20V batteries are not interchangeable — Hart uses a flat connector panel with two divots while DeWalt uses a comb-shaped panel with five divots, so the terminals physically won’t align or transmit power. Forcing a fit with a bypass adapter skips the battery’s safety circuit and can overload the tool or void both warranties. This guide covers the real connector differences, what adapters actually do, and your best options now that Walmart and parent company TTI are discontinuing the Hart line.

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Why Hart and DeWalt Batteries Aren’t Interchangeable

A battery platform is the proprietary rail-and-terminal system a tool brand designs so only its own packs slide onto its own tools. Hart’s platform was built by TTI (Techtronic Industries) exclusively for Walmart; DeWalt’s 20V MAX platform is built and licensed only for DeWalt-branded tools. The two were never designed to cross over, and that shows up in three concrete places.

• Connector shape: A Hart 20V pack has a flat top panel with two divots and a wide recessed slot. A DeWalt 20V MAX pack has a comb-shaped panel with five divots and rails that angle outward. The rails simply don’t line up.
• Terminal placement: Even where the packs happen to touch, the power terminals sit in different positions and orientations, so no current can flow between a Hart battery and a DeWalt tool (or vice versa) without modification.
• Firmware and communication pins: Modern 20V packs from both brands include a communication chip that reports charge state and temperature to the tool. A tool from one brand doesn’t recognize the other brand’s chip, which is part of why some tools simply refuse to power on with a mismatched pack even if a jury-rigged adapter completes the circuit.

Hart vs. DeWalt 20V Battery Specs Compared

Spec	Hart 20V	DeWalt 20V MAX
Voltage platforms	20V and 40V (outdoor/lifestyle)	20V MAX, plus 60V/20V FlexVolt
Common capacities	1.5Ah – 6.0Ah	1.3Ah – 9.0Ah
Connector style	Flat panel, 2 divots, recessed slot	Comb-shaped panel, 5 divots, angled rails
Retail availability	Walmart only — brand discontinued	Home Depot, Amazon, DeWalt dealers
Cell chemistry	Lithium-ion	Lithium-ion

Where the two platforms actually match is voltage class (both run a 20V lineup) and cell chemistry — which is exactly why cross-brand adapters exist in the first place. Matching voltage doesn’t make two connectors compatible; it just means an adapter that bridges the physical and electrical gap has a fighting chance of working at all.

Can You Use a Hart-to-DeWalt Battery Adapter?

Third-party adapters that let a Hart battery plug into a DeWalt tool (or a DeWalt battery power a Hart tool) do exist on Amazon and eBay. They physically bridge the different connector shapes, but they come with a real tradeoff most listings don’t mention.

A battery pack’s internal circuit board is what manages safe charge and discharge rates, temperature cutoffs, and low-battery shutoff for that specific tool. A passthrough adapter routes raw power around that pairing instead of through it, since the adapter has no way to translate one brand’s communication protocol into the other’s. In practice that means either underwhelming performance (the tool doesn’t get the current it expects) or an overload risk (the tool draws more than the mismatched pack’s circuitry was tuned to hand off safely). Adapters also void the warranty on both the battery and the tool, from both Hart/TTI and DeWalt.

📊 TTI announced the discontinuation of the entire HART business via a Hong Kong Stock Exchange filing in December 2025 — Source: Techtronic Industries Holdings, HKEX filing, December 2025.

What the HART Discontinuation Means for Your Batteries

If you’re researching Hart-to-DeWalt compatibility in 2026, there’s a good chance it’s because your Hart batteries are aging out of a brand that no longer exists on shelves. TTI, the manufacturer that also owns Milwaukee, Ryobi, and AEG, confirmed it is winding down the HART line, which was sold exclusively through Walmart. TTI’s own statement framed the move around company economics: “the discontinuation of the HART business further supports our ability to deliver our medium-term internal profitability objectives.”

For anyone with Hart tools already in the garage, that leaves three practical paths, roughly in order of how much it costs you:

1. Stock up on genuine Hart batteries now, while clearance stock lasts. Prices are dropping at Walmart and liquidation retailers as remaining inventory clears — this keeps your current tools running the longest without touching an adapter.
2. Buy a cross-brand adapter and accept the tradeoffs above. Reasonable for occasional, low-torque use (a screwdriver, a light drill); riskier for anything that draws heavy sustained current, like a circular saw or reciprocating saw.
3. Migrate the tool, not just the battery. Once your Hart batteries eventually die for good, replacing the tool itself on an established platform like DeWalt 20V MAX means every future battery, charger, and tool addition works together without an adapter in the loop.

Best Way Forward If You’re Replacing Hart Batteries

If a Hart battery has already died and an adapter isn’t appealing, the simplest fix is starting a small DeWalt 20V MAX kit — a battery-and-charger combo covers the tool you actually need running today, and every future DeWalt battery you add afterward works with it and every other DeWalt 20V tool without an adapter.

If you’re deciding between platforms rather than just replacing a battery, our comparison of DeWalt vs. Makita and our breakdown of whether Ryobi is compatible with other brands cover how the other major cordless ecosystems handle cross-brand compatibility — the short version is almost none of them do, for the same connector and firmware reasons covered above.

Common Mistakes When Mixing Battery Brands

• Assuming matching voltage means matching fit. Hart and DeWalt both sell 20V packs, but voltage class has nothing to do with connector shape.
• Forcing a battery that “almost” fits. Never file, pry, or modify a connector to make a pack seat — that’s how short circuits and swelling happen.
• Ignoring the low-battery cutoff. An adapter can defeat the tool’s normal low-charge shutoff, which risks over-discharging the cell and shortening its life.
• Buying a full Hart tool now, in 2026. With the line discontinued, a brand-new Hart tool purchase has no long-term battery supply behind it.

Can I use a Hart-to-DeWalt battery adapter safely?

You can use one, but it bypasses the battery’s built-in safety circuit, so it’s better suited to light, occasional use (a screwdriver or small drill) than to heavy sustained loads like a circular saw. It also voids the warranty on both the battery and the tool.

What batteries are compatible with Hart tools?

Only genuine Hart 20V or Hart 40V batteries fit Hart tools directly. No other brand’s battery uses the same connector, and Hart batteries only fit Hart tools in return — the platform was never licensed to work with any other manufacturer’s connector.

Why is Hart being discontinued?

TTI, Hart’s manufacturer, confirmed in a December 2025 Hong Kong Stock Exchange filing that it is winding down the HART business, which was sold exclusively through Walmart, citing internal profitability goals. Existing Hart tools and batteries will keep working, but new stock is limited to remaining clearance inventory.

Are DeWalt 20V and 20V MAX batteries the same thing?

Yes. DeWalt markets its entire mainstream cordless line as “20V MAX,” so a battery labeled 20V and one labeled 20V MAX from DeWalt use the same connector and platform.

Can you use a Milwaukee battery in a Hart tool?

No. Even though Milwaukee and Hart are both made by TTI, each brand keeps its own separate connector design, so Milwaukee M18 batteries do not fit Hart tools without a third-party adapter.

Conclusion

Hart and DeWalt batteries are not interchangeable — different connector shapes, different terminal layouts, and different communication firmware all rule out a direct swap. With Hart now being wound down by TTI, the more useful question for most owners isn’t “will an adapter work,” it’s “what happens when this battery finally dies.” Stocking up on genuine Hart packs while clearance stock lasts buys time; migrating to an actively supported platform like DeWalt 20V MAX is the option that doesn’t run out.