If you’re storing batteries for any length of time, don’t leave them with no charge because they may not “wake up” when you want to charge them again. You could try opening the casing and looking for some obvious disconnection fault, but if the electronic control circuit is faulty you will need an electronics specialist to repair it. This effect gets worse each time, so they need to be “deep discharged” (run as flat as possible) before recharging.

The problem might be obvious, sometimes they over heat and desolder a connection, or there is an obvious point where an arc/short has occurred.

However, with Makita’s version of the latter (LXT) now charging in well under an hour, we would still opt for that model. These batteries are more powerful and longer lasting than NiCd batteries, but they’re also more expensive, and care is needed when charging them to maintain performance. If your tool was sold with two batteries and you're a part-time user, stick the extra one in the refrigerator.

Second, whack the battery in your palm as hard as you can a few times, and try to charge/use - sometimes works! They were something of a revolution, but they’re heavy, Cadmium is highly toxic, and the battery performance is limited, as demonstrated by Makita’s early range being just 9.

We wouldn’t trust cheap knock-off batteries, but quality alternatives can save you a lot of money and should be perfectly safe. Batteries in Makita’s latest Li-ion 18V LXT range have a three-year warranty, so clearly the company expects them to last longer. With Li-ion batteries, though the eventual drop-off is more dramatic, they deliver consistent power for longer. Also they can be recharged at any point in the discharge cycle without any ill effects (there is no memory effect). Power tool batteries usually have a good protective casing, so the danger of physical damage is often overlooked.