A lot of us in the maintenance business, as well as many people who like the do-it-yourself lifestyle, own a lot of portable battery-powered tools. These batteries need minimal care, but for maximum battery life, here are a few things to consider.

The old Ni-Cad batteries, which were popular about 20 years ago, are no longer in vogue. Although still in use, they have more or less been replaced by either a nickel metal hydride type or some kind of lithium ion battery.

These newer batteries last far longer than the Ni-Cad kinds, but more importantly, they don't have a recharging memory. That is, you can pop them into their charger when-ever you want and not have to worry about them. The old Ni-Cads needed to be run down to nothing first and then recharged; otherwise, they would never take a full charge.

The newer hydride and lithium batteries have no such problem and can be charged whenever you are done using them.

But before being charged, the batteries should be removed from the tool they are powering and allowed to cool down a bit. Heat is one of the killers of modern batteries, and the hotter they get, the more prone they will be to losing their charge at a faster rate.

Also, these modern batteries should never be run down to zero before getting recharged. They recharge best when they are 80 percent drained, and if this procedure is followed, you will get the longest possible life out of your batteries.

Unless you have a new computerized battery charger, batteries benefit by getting taken out of the charger instead of being left in the charger all the time. The newest of the brand-name chargers have circuitry that will analyze the status of the battery and keep it charged to its optimum, but some lesser battery chargers have a thermal regulator used for their charging cycles. Thermal regulators charge the battery to a certain temperature and then turn off. Under normal use, that works fine, but in high-heat situations or when your battery gets too hot from being used, these chargers will assume the heat from the battery is a sign it is fully charged and therefore will not send any charging current to the battery.

On the other hand, batteries and chargers with a thermal regulator left in a colder environment - say in an unheated garage - will overcharge the battery and in extreme instances, could fuse and melt the battery cells together, causing total failure. So if possible, always try to remove the battery from the charger after a good charge.

You get what you pay for with rechargable batteries and chargers. Brand names such as Milwaukee, Dewalt, Makita and Bosch, to name a few, have the highest quality batteries with computerized chargers for the longest rechargeable battery life. These are the types of chargers where you can place the battery inside, let it charge and it will be ready when you need it, time after time.

Dale Y the Maintenance Guy has been involved in repairs, supervision and as a consultant with maintenance services for more than 18 years. E-mail him at maintenanceguy88 @yahoo.com.