Train Horn Battery Compatibility Chart — Every Brand on One Page (M18, 20V MAX, ONE+, LXT, and More)

Every horn we build runs on a power-tool battery you probably already own — the only real question is which platform you're on. This page is the master chart: all sixteen battery systems we support, what the voltage labels on those packs actually mean, and the loudest horn tier you can hang on each one.

How to Read This Chart

Three things decide which train horn goes on your truck, boat, or UTV:

• The battery mount. Each horn is built with a brand-specific rail, so your pack clicks in exactly the way it clicks into your drill. No wiring, no compressor, no tank.
• The sound tier. Dual trumpets run about 130 dB, Quad trumpets reach up to 140 dB, and the Extreme and Boss Series push past 150 dB. Not every tier exists for every platform — that's the whole point of the chart.
• Voltage labels are mostly marketing. An "18V" pack and a "20V MAX" pack are electrically the same thing: five lithium-ion cells in series at 18 volts nominal. The "20V" number is the peak reading straight off the charger, before any load is applied. So no, a DeWalt "20V" horn is not louder than a Milwaukee "18V" one — and the "20V MAX" label is only even used in North America.

One more spec that's identical across every row below: each horn works with a wireless remote, from the standard 300 ft unit up to the long-range remote rated for up to 2,000 ft.

The Master Battery Compatibility Chart

A quick note on the two 24V rows: Kobalt and Flex packs carry six lithium-ion cells in series instead of the five you get in an 18V/20V pack — Flex's own spec sheet for its 6.0Ah pack lists six cells — which is where the higher nominal voltage comes from. It buys the horn a little electrical headroom, but the decibel rating is set by the trumpets and compressor, not the pack, so the 24V quad horns are rated the same 140 dB as their 18V siblings.

Per-Brand Deep Dives

The chart tells you what exists; these guides cover each platform's quirks — runtime with common pack sizes, mounting, and which tier makes sense:

• Ryobi ONE+ battery train horn guide
• Makita 18V LXT train horn — compatibility, loudness, and runtime
• Bosch 18V train horn guide
• Ridgid 18V train horn guide
• Kobalt 24V MAX train horn guide
• Worx 20V Power Share train horn guide
• Bauer, Hart, Hercules & Craftsman V20 buyer's guide
• Battery adapters — running one brand's horn on another brand's pack

The Big Four: Milwaukee, DeWalt, Ryobi, Makita

If you're choosing a platform from scratch, the top of the chart is where the depth is. Milwaukee M18 and DeWalt 20V MAX are the only two systems that get the entire lineup — Dual through 5-Trumpet all the way to the 150 dB+ Boss Series — and since they're electrically identical 18V-nominal platforms, the decision comes down to which batteries you already own. We put the two head-to-head in our Milwaukee M18 vs DeWalt 20V comparison. Ryobi ONE+ runs surprisingly deep too, including a Boss Series model, while Makita LXT tops out at the Extreme tier.

For M18 owners who want serious volume without stepping up to the Boss, the Extreme Series Train Horn for Milwaukee® 18v Battery is the sweet spot — a 150 dB-class quad-trumpet horn that runs on any M18 pack you clip onto it.

Shop the Extreme Series Train Horn for Milwaukee® 18v Battery →

Retailer House Brands: Hart, Bauer, Hercules, Kobalt, Craftsman

The middle of the chart is where owners of store-brand tools usually give up searching — and it's exactly where a battery horn makes the most sense, because those packs are cheap to add. Hart is Walmart's exclusive tool line, Bauer and Hercules are both Harbor Freight house brands, and Kobalt is exclusive to Lowe's. One trap worth knowing: even brands sold under the same roof don't share packs — Bauer and Hercules batteries are not interchangeable with each other despite both being Harbor Freight lines. That's why every row in the chart gets its own horn with its own mount.

Most house-brand platforms center on the quad-trumpet tier — four trumpets, up to 140 dB, a completely different class of sound than any stock vehicle horn.

Shop quad trumpets →

What If Your Battery Isn't on the Chart?

Outdoor-equipment platforms are the most common miss. EGO 56V and Greenworks packs power mowers and trimmers, not drills, and their mounts are completely different — there's no native horn for them, but adapter routes exist, and we walk through what actually works in our EGO and Greenworks battery train horn guide.

The other answer is to skip the brand question entirely: the DIY Train Horn Gun Kit with Remote is a universal quad-trumpet build rated up to 140 dB that you wire to whatever power source you've got. If your platform is obscure, discontinued, or just missing above, this is the catch-all.

Shop diy kits →

FAQ

Will one brand's battery fit another brand's horn?

No. Every platform uses its own rail shape and terminal layout, which is why each horn in the chart is a distinct product. Third-party adapters can bridge some combinations — see the adapter guide linked in the deep-dives list — but pack-to-pack, nothing is cross-compatible out of the box.

Is a 20V horn louder than an 18V horn?

No. "20V MAX" and "18V" describe the same five-cell, 18V-nominal battery; the 20V figure is just the no-load peak off the charger. Loudness is set by the horn tier — Dual (130 dB), Quad (140 dB), Extreme/Boss (150 dB+) — not by the label on the pack.

Do the 24V Kobalt and Flex horns sound louder?

No. They use the same quad trumpets and compressor as the 18V/20V quad models and carry the same up-to-140 dB rating. The sixth cell in a 24V pack adds voltage headroom, not decibels.

What size battery (Ah) should I run?

Any pack that physically fits will sound the horn at full volume. Capacity only changes how many blasts you get per charge — a 2Ah pack is fine for occasional use, a 5Ah+ pack for a long weekend. We measured the real-world difference in our 2Ah vs 5Ah vs 9Ah runtime comparison.