Do Makita XGT 40V Batteries Work With a Train Horn Gun? (And What XGT Owners Should Buy Instead)

Short answer: no. A Makita® 40V max XGT® battery will not run a train horn gun — it won't even slide onto the mount. Battery-powered horn guns for the Makita platform are built around the 18V LXT® pack, and Makita designed XGT so the two systems never cross over.

The Short Answer: XGT Packs Don't Fit the LXT Mount

Makita runs two separate cordless battery systems in the US. 18V LXT is the long-running one, and Makita now lists it at 350+ products. 40V max XGT is the newer high-output system for heavier work, at 170+ products. Each system has its own rail, its own terminal layout, and its own battery electronics, and there is zero cross-compatibility between them: an XGT pack won't fit an LXT tool, and an LXT pack won't fit an XGT tool.

A train horn gun for Makita® batteries uses the LXT slide-on mount — the same rail you'll find on an LXT drill or blower. That means the rule for the horn is the same as the rule for any LXT tool. Try to slide an XGT pack on and it simply won't seat. Nothing lines up, and no amount of pushing changes that.

So if your shop went all-in on XGT and you were hoping those packs would run a horn too, they won't. The fix is cheap and simple, and we'll get to it below. First, it helps to know why Makita keeps the two systems apart, because it also explains why an adapter is a bad idea.

Why Makita Keeps XGT and LXT Apart

XGT exists for jobs that used to call for a cord, a gas engine, or an air line. Makita says the LXT system handles most applications and positions XGT as the higher-powered option for demanding ones. XGT tools also use brushless motors built with more copper windings for more power output. Those tools are engineered around a battery that delivers roughly twice the voltage of an LXT pack.

The voltage gap is the whole story. An XGT pack is marketed as "40V max" but is rated 36V nominal, the same labeling convention that turns an 18V-nominal pack into "20V max." An LXT pack is 18V nominal and tops out around 20–21V off the charger. Put those side by side:

System	Label	Nominal voltage	Products (Makita US)	Runs a train horn gun?
LXT	18V	18V	350+	Yes — this is the one
XGT	40V max	36V	170+	No — different rail, double the voltage

A horn gun's compressor motor and trigger switch are built for the 18V window. Feeding them a 36V-nominal pack would roughly double what they were designed to handle. That's a fast way to cook motor windings or burn out a switch, and it's the reason the two mounts are keyed so you can't mix them up by accident.

What About the Makita ADP10 Adapter?

This is where most of the confusion comes from. Makita does sell an adapter that bridges XGT and LXT: the ADP10. But look at its full name: 18V LXT Adapter for XGT Chargers. It plugs into a 40V max XGT charger so that charger can charge 18V LXT batteries. Makita rates the setup at about 40 minutes for an LXT 5.0Ah or 6.0Ah pack and 24 minutes for a compact 2.0Ah.

That's all it does. The ADP10 is a charger-side accessory. It doesn't let an XGT battery power an LXT tool, and it doesn't let an LXT battery power an XGT tool. Makita doesn't make any tool-side adapter between the two systems, in either direction, so there's no official way to put an XGT pack on a horn gun.

The ADP10 does help XGT owners in one way. If you pick up a couple of LXT packs just for the horn, you don't need a second charger. Your XGT rapid charger plus an ADP10 will keep them topped off.

Third-party XGT-to-18V adapters do show up online. Most of the cheap ones just reroute the contacts without stepping the voltage down, and that sends a 36V-nominal pack straight into 18V hardware. Skip them. We cover the whole adapter question, including when adapters make sense for an actual 18V-to-18V brand swap, in our guide to cross-brand battery adapters on a train horn gun.

What XGT Owners Should Buy Instead

You have three good options. The right one depends on what else is sitting on your charger shelf.

• Add one LXT pack and run a Makita-compatible horn. This is the most direct route. Any genuine 18V LXT slide-on pack runs our Makita-mount horns, from the compact 2.0Ah to the 6.0Ah. A horn gun only draws current while you're holding the trigger, so even a 2.0Ah pack is good for roughly 500 or more short blasts. It also charges on the XGT charger you already own if you add the ADP10.
• Use a pack from another brand you already own. Plenty of XGT shops also have a drill or two from another platform. We build the same horn for Milwaukee® M18™, DeWalt® 20V MAX™, Ryobi® ONE+™, Bosch® 18V, and more. If you already have one of those batteries, you don't need to buy one at all. Our train horn battery compatibility chart by brand shows which pack goes with which horn.
• Go the DIY route with a brushless drill. The universal DIY 4-trumpet train horn gun kit pairs with a brushless drill instead of mounting a battery directly. It's the flexible option if you'd rather work with a tool you already have.

For most XGT owners, the first option wins. It's one extra battery instead of a workaround, it's a genuine Makita battery with Makita's own protection electronics, and you get a native fit with no adapter in the power path. Everything you need to know about which LXT packs work, and how many blasts each Ah size gives you, is in our Makita 18V LXT train horn compatibility guide.

Which Horn Fits Makita LXT Batteries

Our Makita-mount lineup comes in three steps. The dual-trumpet horn for Makita® LXT batteries is the compact everyday-carry option. The quad-trumpet horn gun for Makita® batteries is louder. At the top, the Extreme Series quad for Makita® batteries uses longer trumpets for a lower, deeper tone. All three slide onto the same LXT pack, and none of them accept XGT.

Loudness comes from trumpet count, not battery brand. If you also keep Milwaukee® packs on the shelf, the loudest configuration we make is the 5-Trumpet Horn Gun for Milwaukee® 18V Battery, which runs on any M18 pack.

FAQ

Will a Makita XGT battery physically fit on a train horn gun?

No. Makita-mount horn guns use the 18V LXT rail, and XGT packs use a different rail and terminal layout. The pack won't slide on, so there's no way to hook it up by accident.

Does the Makita ADP10 let me run an XGT battery on an LXT tool?

No. The ADP10 is an "18V LXT Adapter for XGT Chargers." It lets an XGT charger charge LXT batteries, nothing more. It's still useful if you add an LXT pack for your horn, since your existing XGT charger can then charge that pack too.

Is there a Makita-compatible horn that runs on XGT packs?

Not from us. Every horn we build for Makita® batteries uses the 18V LXT mount, because that's the voltage the compressor is built for and the pack most Makita owners already have.

Do the new XGT tools make LXT batteries obsolete?

No. Makita still sells both systems side by side and lists 350+ LXT products next to 170+ XGT products. LXT packs remain the standard for 18V tools, and that includes horn guns.

Is this the same situation as Ryobi 40V?

Yes, almost exactly. Ryobi's 40V line is also a separate, higher-voltage platform that won't fit an 18V horn gun. We explain it in do Ryobi 40V batteries work with a train horn gun. The only high-voltage pack we know of that runs a horn gun is DeWalt FLEXVOLT, because that pack switches itself down to 20V on a 20V-class mount.