Bosch tells all on its most advanced battery platform yet

Professional Builder charts the journey to Bosch’s most advanced battery platform and power tool range yet – ProCORE18V and BiTURBO. Chris Murray, Digital Power Tool Training Manager for the manufacturer, explains some of the flagship technologies involved.

Bosch has a long and illustrious history across multiple sectors, but the company’s first point of departure from its original automotive roots was power tools. Indeed, the German manufacturing giant has an excellent heritage in SDS hammers in particular – having invented the concept of SDS itself – and can even claim to have developed the world’s first battery-powered rotary hammer drill.

The GSB 18V-150 C is the most powerful cordless combi in the Bosch range

Today, around 80% of professional end users are purchasing cordless, with the levels of power and convenience in battery powered solutions improving exponentially in recent years. Indeed, performance is now equal to or greater than corded equivalents, even when using a 12-volt system. Of that aforementioned 80%, around 90% of those cordless users are estimated to be on an 18V platform. With the goal for the tradesperson to make use of one system – where all their batteries are compatible with the tools they already own and use – loyalty to a battery system now plays a greater part than ever in the choice of power tool brand.

It’s not all about batteries, of course, because Bosch is continually developing its technologies, and the manufacturer has been systematically updating its existing products with brushless motor models. As a result, the manufacturer can now point its customers towards a complete range of brushless combis and drill drivers.

The latest entry level brushless 18V cordless combi, for example, is the GSB 18V-45 – where the 45 designation represents Newton Metres (Nm). As an indication of the additional performance accrued from brushless consider that it’s a lot smaller, but still more than twice as powerful as its brushed predecessor, which could generate only 21Nm of torque.

Added to that are the GSB 18V-55, GSR 18V-55, GSB 18V-60 C, GSB 18V-90 C, GSB 18V-110 C and GSB 18V-150 C – all with brushless motors. Brushless motors are more efficient and can offer up to 30% longer runtime. With no carbon brushes to wear – and fewer moving parts – the lifetime is up to twice as long, and they’re more robust as machines.

Another considerable claim to fame is the first power tool with lithium-ion battery power. Introduced in 2003, the IXO ran a single 18,650 cell – 18x65mm in dimensions – and was a 1amp hr battery. The advantages of lithium-ion batteries are now well known, of course. They have very good power output and energy density. They can be charged quickly and discharged equally swiftly on heavy duty applications. The nemesis of any lithium-ion battery, however, is heat. Any battery of this type will heat up with use and its mitigation has required further technological innovations.

As a result, Bosch was very quick to pair lithium ion with battery management systems and electronic cell protection that will stop the machine if it’s in danger of overheating. Essentially, it regulates the amount of charge, discharge or current coming out of the battery, giving it up to four times longer lifetime and, again, is all part of a commitment to ensure that a power tools users investment is protected.

The next advance from the boffins in the Bosch R&D department was the Coolpack battery platform, launched in 2007. Here, a HDPE (High Density Poly Ethylene) material transfers the heat away from the cells. ProCORE18V is the latest great leap forward in battery technology. Instead of utilising 18,650 cells that will deliver 45amps of current from a dual layer battery, it features an upgrade to 21,700 – or 21x70mm in dimensions. A physically bigger battery means it will store more energy and more current can be drawn from it – but why the need?

The evolution of Bosch battery technology to the ProCORE 18V

What end users have been demanding for some time is battery power that could run much larger and more powerful machines, such as mitre saws, larger rotary hammers and breakers. Whilst its competitors have gone down the dual battery route, with two 18V batteries powering a single tool, Bosch has rejected that solution and there are sound technical reasons for doing so.

Instead, the ProCORE18V battery platform will do the job very nicely with a single 18V unit. Indeed, with a dual layer battery featuring 21,700 cells 90 amps of current are available – double what was previously available on the Coolpack generation. That increase requires a new battery design with copper contacts that benefit from lower internal resistance and better electrical transfer. The original HDPE Coolpack configuration was also redesigned so that every cell is fully encapsulated in the material. Moreover, a Thermo Plastic Elastomer (TPE) sits alongside the copper contacts, conducting heat away from the side of the batteries. All of that technology comes together to produce a battery that is capable of discharging heat from all four of its sides.

“We drilled 110 holes, 10x100mm into concrete with one of our smaller hammer drills – with a single ProCORE18V 8.0 Ah battery – during the heatwave of 2022 and the machine kept going without the Electronic Cell Protection kicking in once,” explains Chris Murray, Digital Power Tool Training Manager for the manufacturer and expert in all things Bosch Professional.

ProCORE18V and BiTURBO

Armed with the new ProCORE18V battery, Bosch can power the bigger, more powerful machines that make up the new BiTURBO range. Not only does it promise corded equivalent power with just one 18V battery but machines that can equally outperform tools in higher battery voltage classes. Combined with its high-performance brushless motor, in tools such as the Bosch GCM 18V 305 GDC12in. Sliding Mitre Saw, it can unleash power up to the equivalent of 2,000 watts of corded power. That makes it the performance equivalent of the mains-powered GCM 12 GDL 12in. Sliding Mitre Saw.

The GCM 305 GDC Sliding Mitre Saw using just one 12.0 amp hr ProCORE battery

BiTURBO tools also benefit from the latest safety features, including KickBack Control, Drop Control and Vibration Control. The BITURBO range is flexible enough to be fully compatible with the rest of the Bosch 18V battery platform and they can be run on a standard 18V battery. With a 8kg hammer, however – because the BiTURBO range has been specifically developed from the ground up to run with ProCORE18V batteries – including a bigger and more powerful brushless motor – you’ll only get around 50% of the performance.

With Bosch the message is clear: Just one ProCORE18V battery will suffice on heavy duty applications where some competitors will either use higher voltage batteries or a dual battery system.

The top-of-the-range GWX 18V-15 SC Angle Grinder

Given the increased performance, it does rather beg the questions as to why anyone would now choose corded but, as Chris explains, it’s really a matter of horses for courses. “The first ProCORE18V battery was an 8amp hr unit – with a 12amp hr subsequently introduced – and that was in comparison with a 4amp hr standard 18V, which has already doubled the capacity. If you’re running a high-powered machine all day, however, even with that additional runtime, then corded still has its place.”

The ProCORE18V range of batteries now includes a 5.5, 8, and 12 amp hr unit. It’s important to note that the 4amp hr ProCORE18V is lighter and more compact than the standard Coolpack 18V 4 amp hr. It can do that because the aforementioned 21,700 cells can be arranged in a single layer, as opposed to a double layer of 18,650 cells in the Coolpack. At the same time, if you need the maximum performance, the 4 amp hr ProCORE18V battery is not recommended for a BiTURBO machine. The batteries that have been specifically designed for high draw applications would be the 5.5, 8 and 12amp hr.