Bosch 18V Connected Angle Grinder GWS18V-45CN Review

Bosch 18V Connected Angle Grinder GWS18V-45CN Review
PTR Review
  • Build Quality 9.5
  • Feature Set 9.5
  • Ergonomics 8.5
  • Power 9.0
  • Value 8.5

While it's possible to find a more powerful cordless grinder with other voltages, the Bosch 18V Connected Angle Grinder is a really well-rounded choice.

Overall Score 9.0 (out of 10)

I love angle grinders. There’s something manly about taking a tool to metal, creating a shower of sparks, and doing it for a more productive reason than mere fun. Cordless angle grinders are pretty common on the 18V/20V Max platform these days and they’re becoming pretty effective. With a reputation for solid build quality, the new Bosch 18V Connected Angle Grinder comes in with more than just an ax to grind – it’s the first tool Bosch has specifically designed around their Core18V battery.

We’ll get down to the features and performance of the grinder momentarily.

In the meantime, consider the current landscape of grinders. Milwaukee has a 9.0 Ah battery pack, DeWalt has their FlexVolt grinder, Hitachi just announced their MultiVolt line that will include an angle grinder, and Hilti is running on a 22V platform instead of 18V. Despite all of this, I’m genuinely excited about the Bosch GWS18V-45CN.

So let’s take a closer look to see what all Bosch includes in this package.

Notable Features

  • Brushless Motor: If you’re going to build a flagship cordless angle grinder, you better start with a brushless motor and Bosch does.

Brushed Vs. Brushless Motors: What’s the Difference?

  • Core18V Foundation: Like I said earlier, this is the first tool Bosch designed to take full advantage of the Core18V battery’s potential. It has better lithium-ion cells surrounded by a better build that makes a legitimate difference in performance.

Bosch CORE18V Battery Review – UPDATED

  • Connected-Ready Design: Bosch’s connected tools are just making their way into the mainstream conversation. The Bosch 18V Connected Angle Grinder uses the GCY30-4 Bluetooth Module that integrates into the tool body. More on that later.

Bosch 18V Connected Angle Grinder GWS18V-45CN Review

  • Drop Control: The Bosch GWS18V-45CN is the side switch, lock on model with obvious implications if you happen to drop it while it’s on. Built-in sensors shut the tool off if they detect a drop.


  • Kickback Control: Likewise, there are sensors that detect when the wheel gets itself in a bind that it can’t push through. The tool will shut itself off in bind-up situations to help protect you from injury.


  • Restart Protection: If you leave the power switch in the on position and then insert a battery, it won’t turn on. You’ll have to switch it off first and you may notice that if you turn it off and back on too quickly, the restart protection will prevent it from coming back on. It’s all about preventing accidental startup.


  • Soft-Start: Soft start can help you ease into your cut or grind and also helps reduce the side jerking you feel when you turn the grinder on.


  • Two Position Auxiliary Handle: The auxiliary handle can install on the left or right side. Some grinders offer a top position that helps on vertical cuts and grinds that would be nice to see in the next edition, but it’s hardly a deal-breaker. The handle itself provides a little bit of vibration dampening before it reaches your hand.

Bosch 18V Connected Angle Grinder GWS18V-45CN Review

Bosch 18V Connected Angle Grinder – Connected to What Exactly?

Bosch Connected Tools work with your smartphone and the Bosch Toolbox app. There’s a ton of stuff going on in there from report sheets to social media links and a lot in between. The “My Tools” section is where you’ll work with the tool, though.


In here, you can check for a host of information including:

  • Last seen date and time
  • Soft start on/off
  • Factory reset
  • Battery charge status
  • Phone to tool signal strength
  • Custom tool naming
  • Tool specifications
  • Usage info (total runtime, kickback activations, restart protection activations, and drop control activations)


Realizing that this is a 4-1/2″ 18V grinder puts things into perspective a bit. It doesn’t matter what battery you use, it’s not going to shred metal like a 9″ grinder. That said, it’s the battery that I really wanted to test. After all, Bosch designed the tool around the Core18V battery.

Bosch 18V Connected Angle Grinder GWS18V-45CN Review

So I grabbed some 5/8″ rebar, charged up the batteries, and got my hands on some cutting wheels before letting the sparks fly. Here’s what happened:

Bosch 4.0 Ah batteryBosch 18V Connected Angle Grinder GWS18V-45CN Review

  • Fastest Cut: 31.0 seconds
  • Total Cuts on a Single Charge: 10

Bosch 6.0 Ah battery

  • Fastest Cut: 18.3 seconds
  • Total Cuts on a Single Charge: 15

Bosch Core18V battery

  • Fastest Cut: 10.7 seconds
  • Total Cuts on a Single Charge: 21

As you can see from the numbers, there’s a significant difference from one battery to the next. The Core18 that the Bosch 18V Connected Angle Grinder is designed for made 110% more cuts than the 4.0 Ah pack and 40% more than the 6.0 Ah. For cutting speed, it reduces the cutting time to 35% of what the 4.0 Ah battery takes and 58% of what the 6.0 Ah battery needs.

Bosch 18V Connected Angle Grinder GWS18V-45CN Review

What’s really impressive about those results is that the Core18V battery is a 6.3 Ah, 18V pack. It only has 113 Wh compared to 108 Wh in the 6.0 and 72 Wh in the 4.0. When you break that down, the Core18V battery does 110% more work with only 57% more energy than the 4.0 Ah pack. Compared to the 6.0 Ah pack, Core18V is doing 35% more work with just 4.6% more energy. That’s a huge difference.

Is it All Sunshine and Rainbows?

Few tools are perfect, and Bosch’s new grinder is no exception to that rule. I’m a paddle switch kind of guy when it comes to grinders and this has a side switch. That’s not really a big deal since Bosch has a paddle switch version.

Bosch 18V Connected Angle Grinder GWS18V-45CN Review

I’d really like to see that main handle come in a smaller diameter for a more comfortable grip, especially when I turn it for working with horizontal materials. Likewise, a middle auxiliary handle attachment point would help for those same cuts and grinds.

While this might also be stretching a bit, I love quick lock flanges to reduce or eliminate the need for a spanner wrench. Like most angle grinders, the wrench doesn’t store on board and it will eventually seek its freedom somewhere in a dark corner, never to be seen again.

On the safety side, the wheel is slow to stop. Adding an electric brake should be a top priority in the next model since there are already electronics for the brushless motor.

Price and Value

You can get either Bosch 18V Connected Angle Grinder style for $169.00 as a bare tool. That’s pretty much a top of the line price for a grinder is this class. However, this is the first connected grinder we’ve seen hit the market and those tools seem to be settling in with a $50 premium, more or less. Given the excellent build quality and that the only major feature lacking is an electric brake, that’s a pretty reasonable price to pay at this stage.

The Bottom Line

In the 4″/5″ 18V angle grinder class, the Bosch GWS45-18CN puts on a show when you use the Core18V battery. Build quality is excellent, the feature set really only lacks an electric brake, and the pricing is right where we expect it to be. While it’s possible to find a more powerful cordless grinder with other voltages, the Bosch 18V Connected Angle Grinder is a really well-rounded choice.

Bosch 18V Connect Angle Grinder Specifications

  • Model: Bosch GWS18V-45CN
  • Power Source: Bosch 18V battery (optimized for Core18V)
  • Wheel Diameter: 4-1/2″
  • No Load Speed: 9000 RPM
  • Weight: 4 lbs, 5 oz. (with aux handle), 6 lbs, 1 oz (with aux handle and Core18V battery)
  • Warranty: 1 year
  • Price: $169.00
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