In todays building trade the cordless SDS hammer drill is an extremely beneficial
piece of kit to have in your arsenal, especially if you are employed within the construction industry. If you are required to drills holes for any a reason and into any type of surface you will find the only real limiting factor these days is the efficiency and life of the rechargeable battery.
Batteries used and made for the SDS drills are generally around 36 Volts, any less than this and it becomes very inefficient to use them. The manufacturer Dewalt for example have just recently brought out a range of cordless sds drills in the range of 28 to 36 volts. Nevertheless because of the undertaking demanded with these type of power tools it cause a very rapid drain on the batteries. As a result you will find very quickly you'll need to recharge them extremely frequently. In this case is makes very good sense to invest in a second battery .
Make sure you use good Drill bits
Working with dependable drill bits such as the ones supplied by the top brands in the marketplace will ensure less power is required to drill a hole. This in turn saves a lot of the battery charge meaning that recharging will be less required less frequently. The drill bits can and will become blunt extremely rapidly if you are not using the correct on for the job at hand. Steel for instance is required to be penetrated using only the toughest of drill bits. These can be found at reputable manufacturers such as Dewalt and Matika. When eventually they do become blunt the torque required to get through needs to be higher. Make certain that the settings on your cordless SDS hammer drill are correct..
Sooner or later your battery will be drained and it will not matter how long you put it on charge for, it will start to lose it's charge more quickly. This is the time to purchase a new one. This isn't a design defect or fault of the manufacturers but rather the natural limitations of rechargeable batteries in general.