We have a Firestorm drill and have had conflicting advice on charging the batteries. which is correct flatten the battery right down or charge as soon as it loses power. ?? thankyou Colin.

I don't think the newer ni-cad batteries have the memory problem...owner's manuals now say to run them until they start to slow down and then recharge them.

There are different types of battery, the old ni-cad (nickel cadium) batts lasted longer if you let them run right down before recharging them as they had a 'memory' which meant if you charged them from half life they wouldn't charge as much after a while. The new Ni-mh (nickel metal hydrate) and li-ion (lithium ion) batterys don't suffer from this problem so you can recharge them whenever you fancy. The li-on batts don't tend to run compleetely out of charge as when tehy have lost a certain amount of power they just stop anyway. If your batt has lost some life it is possible to get it re-formatted' in some cases by having it put on a battery discharge tester. This is a bit of kit that fully discharges a battery from full in a short space of time and measures it's capacity by timing it. Because it completely discharges and recharges teh batt acouple of times quickly it can someetimes reinvigourate the batt.