Cordless SDS drill guide – buyer’s advice

A cordless SDS drill is an investment – there’s no doubt about it. Good cordless SDS drills don’t come cheap, but if you use them often and push them to the limit, it can be a price worth paying.

Here are the main things to think about:

Which brand?

Very much a personal choice. Leading names in cordless SDS drills such as Bosch and DeWalt tend to invest more in developing and marketing technology such as Li-ion batteries and Vibration control. The big consideration is compatibility – if you’ve invested in a cordless powertool from one brand, it’s a definite advantage to be able to switch batteries and other components/accessories between tools. The Makita LXT range is a good example of cross-compatibility of batteries between different types of tools.

How much power do you need?

Cordless SDS hammer drills tend to be 18V/24V or 36V. If you’re going to be drilling big holes or using a hole saw or core cutter consider a 36V model – almost as powerful as mains. Models such as the Bosch 36 V-LI Compact Professional SDS Rotary hammer are fairly lightweight (2.9kg) so overhead drilling is easy. The drill’s power is determined by the quality and type of battery.

To get a sense of how much power the the drill will actually deliver, look for max. drilling capacity in common building materials. This is usually  described as: masonry XXmm, wood XXmm, steel XXmm. Anogther indicator is the level of impact energy in Joules (J) the drill delivers. To give you a sense of range, a cheaper 24v cordless SDS will give you 1.7J whilst a rip roaring 36V Bosch V-LI or Makita will hammer along a 3.0J. There’s a big difference there.

Battery types for cordless SDS drills:

Nickel Cadmium (NICad) – the older type, typically cheaper but heavier with a shorter battery life. NICads can suffer from ‘battery memory effect’ when it can no longer be fully charged due to it being repeatedly charged without first being fully depleted.

Nickel Metal Hydride (NiMH) – now very common in cordless SDS drills, NiMH have a longer run-time and larger energy storage capacity than the NiCad but don’t accept as many charges.

Lithium-Ion (Li-ion) – is the latest innovation in powertool batteries with Li-ion cordless SDS drill becoming common but still pricey.Li-ion is pretty impressive technology that means more power, less weight and accelerated recharging times. For example, Makita claim that 18V power can be obtained from a Li-ion battery that weighs the same as a standard 12V battery and the latest Makita Li-ion SDS drills recharge in just 22 minutes (e.g. Makita LXT SDS+ Rotary Hammer Drill 36V/24V/18V). The Bosch equivalent the GBH 36 V-LI cordless SDS drill charges in 30 minutes and claims to drill 100 holes in concrete (6x40mm) in one charge. Li-ion batteries also offer additional features such as Electronic Cell Protection and Fan Cooling to protect their lifespan.

To justify the price tag you need to be a heavy user (or seriously addicted to powertools).

IMPORTANT: when choosing SDS drill batteries get the highest Ah you can afford.

Batteries are rated by Amp Hours (Ah) which is the  power stored in the battery. The greater the Ah, the longer the charge will last. So typically a 3.0Ah battery will last longer than a 1.3Ah or 2.0Ah. You might see what seems like a great deal but when you look closely the Ah of the batteries with the drill are lower than equivalent packages on offer.

Warranty – if you’re spending a hefty sum you may want more than the standard 1 year warranty. Some manufacturers offer a 5 year warranty – a big plus and a reflection of the toolmaker’s confidence in the quality of their SDS drills.