http://www.toolcritic.com/glossary.html your best resource for researching tools online en-us Copyright (c) 2007 Critical Pursuits. All Rights Reserved. Fri, 16 May 2008 08:00:05 GMT Fri, 16 May 2008 08:22:18 GMT feedmaster@toolcritic.com feedmaster@toolcritic.com 60 http://www.toolcritic.com/glossary.html#a_glossary-15 Batteries made with lithium ion are the emerging choice for battery powered tools. The have greater energy densities than nickel cadmium (NiCad) or nickel metal hydride (NiMh) batteries making deliver the same power in a lighter package. Lithium ion batteries have no 'memory effect' and they self-discharge very slowly. However, they are expensive and require the most complex battery charging circuitry so that tools using them command a high price. Fri, 16 May 2008 08:22:17 GMT http://www.toolcritic.com/glossary.html#a_glossary-14 Batteries made with nickel metal hydride have better energy densities than batteries made with nickel cadmium (NiCad) but not the energy density of lithium ion batteries, the emerging choice for battery powered tools. They are less prone to 'memory effect' than NiCad batteries, but deep discharges may degrade their life. Thu, 15 May 2008 08:17:59 GMT http://www.toolcritic.com/glossary.html#a_glossary-13 Batteries made with nickel cadmium have been around a long time and are tried and true, but they have lower energy densities than newer nickel metal hydride (NiMH) and lithium ion (Li-Ion) batteries. They are also more prone to the 'memory effect' if not discharged below about 60% before recharging. Nicads are the least expensive tool batteries and they have good low temperature performance and are fairly forgiving about deep discharges or over charging. Wed, 14 May 2008 08:19:21 GMT http://www.toolcritic.com/glossary.html#a_glossary-12 The difference of electrical potential between two points of an electrical circuit. Voltage measures the potential energy of an electric field to cause an electric current. The amount of power used by a tool is the product of the amperage (or current) and the voltage (P=VI). At higher voltages, tools can operate at lower amperages which reduces the requirement for larger wires. Doubling the voltage delivers allows the amperage to be reduced by one-half. Tue, 13 May 2008 08:17:33 GMT http://www.toolcritic.com/glossary.html#a_glossary-11 Also known as current, amperage is the amount of electrical energy flowing through a wire at a specific given time. The unit of measurement is expressed in amperes which is often shortened to amps. The amount of power used by a tool is the product of the amperage and the voltage (P=VI) so that a tool with a higher amperage rating will consume more power and generally generate more torque than a tool with a lower amperage rating. Mon, 12 May 2008 08:18:07 GMT