Bullmax Post Drivers: Choosing a Petrol or Battery Model

Anyone who's spent a weekend swinging a manual post thumper knows just how quickly your shoulders and back start yelling at you. That’s where a Bullmax post driver comes to the rescue. But picking the right model always comes down to what you're putting into the dirt. Standard star pickets, maxi posts, and heavy pipe strainers all need different guides and sleeves—even if two drivers share the exact same Honda engine.

Here at The Grit, we stock both Honda-powered petrol units and Bullmax's Bull Charge cordless kit. Here’s a straight-shooting breakdown of the four main options so you can match the right driver to your fence line.

Start with your post size and shape

Before you hit checkout, take two minutes to write down the posts you'll be driving: the material, shape, and actual dimensions. If you're running branded pickets like Clipex BEEFY or Waratah Maxi, note down the exact product names too. Matching those specs against the driver's included sleeves and adaptors will ensure you grab the right setup right out of the box.

A quick heads-up: just because a driver housing looks big doesn't mean it’ll suit any post. You need the right guide sleeve and dolly to keep the post straight and avoid mushrooming the top. For steel pipe, always measure the actual outside diameter (OD)—nominal bore (NB) ratings can catch people out!

Four Bullmax post drivers to consider

Honda GX35: BMPD-H35-2

If you're after a reliable petrol setup for everyday star pickets, light pipe, or earth stakes, the Bullmax GX35 post driver is a fantastic place to start. It runs on the trusty Honda GX35 4-stroke motor, so there’s no messing around with 2-stroke fuel mixing and no air hoses tethering you to a compressor.

It comes packed with four sleeve sizes—45mm, 55mm, 73mm, and 80mm. Bullmax also built in an 80mm impact plate that lets you drive suitable pipe up to 50mm without having to muck about with a separate dolly. You also get a sturdy carry case to chuck in the back of the ute.

This is your go-to for standard rural fencing runs. Just make sure your posts match those sleeve sizes before banking on the biggest collar fitting everything.

Heavy-Duty Honda GX50: BMPD-H80-2

Stepping things up a gear? The Bullmax Heavy-Duty GX50 post driver is the one to look at if you're working with oversized pickets, timber stakes, or medium pipe. It pairs a gutsier Honda GX50 4-stroke engine with 55mm and 75mm adaptors seated in an 80mm post guide housing.

Bullmax designed this workhorse to handle standard pickets alongside chunky profiles like AG POST MEGA, Whites Stock Post XL, Waratah Maxi Y, and Clipex BEEFY. It'll also tackle 50mm × 50mm timber stakes and pipe up to 65NB using the right sleeve. A heavy-duty carry case is included here, too.

If you're eyeing this model, take a close look at your post measurements against the supplied adaptors. Just keep in mind that while it's dubbed "Heavy-Duty", rock-hard ground or baked clay can challenge any tool, so always keep your local soil conditions in mind.

Battery power: BMPDB-B80 Bull Charge kit

Want to leave the petrol can and pull cords behind? The Bullmax Bull Charge post driver kit is an awesome cordless alternative. It runs on a 36V brushless setup using two 18V batteries, and the kit includes two 8.0Ah Bull Charge batteries plus a dual rapid charger.

Under the hood, you get a 750W brushless motor, 55mm and 75mm sleeve heads, an 80mm post guide housing, and a custom carry case. It handles both standard and maxi pickets, timber pegs, and suitable pipe—all with zero exhaust fumes in your face.

Just consider your access to power before jumping in. Runtime depends entirely on how hard your ground is, so plan your day around your run rather than counting on a set post count per charge. If you’re tackling huge fence runs out back, an extra set of batteries is well worth having on hand.

For larger strainer posts: BMPD-H120 Super Maxi

When it comes to sinking big strainer assemblies, you need the heavy artillery. The Bullmax Super Maxi GX50 post driver is engineered specifically for larger posts, running the Honda GX50 4-stroke engine and coming ready with a dedicated 100NB pipe dolly.

Bullmax makes reducing sleeves in 55mm, 75mm, 80mm, and 98mm sizes for this driver. Before ordering, check the product inclusions carefully to confirm which sleeves come in the box versus what needs to be bought as an extra accessory for your specific post diameter.

Only pick this machine if you genuinely have big strainer posts to drive. Even though it shares the GX50 engine with the H80-2, the larger front-end housing and driving components are built for a completely different class of post.

Petrol or battery: match your worksite

Going petrol gives you all-day runtime as long as you’ve got a jerry can in the ute, though you’ll need to keep up with basic engine servicing and oil checks. Battery gives you instant pull-the-trigger convenience without the engine noise, but you need a spot to charge. Whichever route you take, don't skip lubing up the hammer mechanism as recommended in the manual!

Think about the physical side of things, too. You’ll be lifting this driver up and over posts all day, so factor in post height, footing on steep paddocks, and weight. Make sure you check the actual operating weight of the unit, not just the shipping weight with packaging.

Before the first post goes in

Don't risk hitting something hidden. Always check for buried pipes and cables before you sink a post. Jump onto Before You Dig Australia and follow the asset plans carefully. Keep in mind that private farm lines or irrigation pipes might not show up on official maps, so double-check your paddocks.

Once you’re in the clear, take five minutes to skim through the driver manual (and the Honda booklet if you went petrol). Chuck on your ear protection, safety glasses, and sturdy gloves, keep your mates out of the drop zone, and inspect the tool before firing up.

Find your Bullmax setup at The Grit

Nailing down the right driver really comes down to three things: what posts you’re using, what the soil is like, and how you prefer to power your tools. Once you have those sorted, matching up the right sleeves and dollies is straightforward.

Take a look at our full range of post drivers and lifters to find your setup. And if you’ve got an old fence to pull down before the new one goes up, grab a post lifter while you're at it to save your back on both ends of the job!