1. 0 Beach Cities Robotics FRC Team 294 Summer Academy Batteries and Soldering July 20, 2008 Rick Wagner, Mentor, Beach Cities Robotics FIRST Team 294

2. 1 Batteries and Soldering Outline Concepts: Batteries Types Characteristics Charging Soldering Theory Practice

3. 2 FRC Battery Lead-acid (H 2 S0 4 ) sealed motorcycle battery can supply more than 40 amperes for two minutes Heaviest single component in the robot Wear safety glasses when charging and handling A battery explosion can ruin your whole day (and blind you for the rest of your life) A shorted battery will heat up rapidly and explode Wear no rings or watches when handling batteries A short across a ring will heat it red hot: you will lose your finger Unlike the VEX battery (Nickel-Cadmium, NiCad), a lead-acid battery does not need conditioning to take a full charge A Ni-Cad battery needs to be deep discharged before recharging for a maximal charge

4. 3 2006 Battery ES18 Mfr Spec

5. 4 AGM Type Automotive Sealed Lead-Acid Battery AGM is Active Glass Mat

6. 5 NiCd Batteries The principal advantages of NiCd over other rechargeable types is lower weight for a given quantity of stored energy, good charging efficiency, small variation in terminal voltage during discharge, low internal resistance, and non-critical charging conditions. (Wikipedia) Certain usage patterns may cause a "false bottom" effect. Specifically, if the battery is consistently discharged to the same level, then fully recharged, the battery will eventually stop discharging on its own upon reaching this threshold. (Wikipedia) When not under load or charge, a NiCd battery will self- discharge approximately 10% per month. (Wikipedia) If the battery is going to be stored unused for a long period of time, it should be discharged down to at most 40% of capacity (some manufacturers recommend fully discharging, or even short-circuiting), and stored in a cool, dry environment. (Wikipedia)

7. 6 Soldering Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a relatively low melting point. Soft soldering is characterized by the melting point of the filler metal, which is below 400 °C(800 °F). The filler metal used in the process is called solder. Applications: Attaching electrical components to circuit boards Electrical wiring attachment Plumbing with copper pipes Food cans Rain gutters Automotive radiators Jewelry Joining stained glass Small mechanical parts

8. 7 Soldering Concepts Oxidation Wetting Capillary action Flux Electronic solder (63% tin, 27% lead (eutectic)) with rosin core flux Unsoldering

9. 8 Soldering Techniques Wear safety glasses Make a good mechanical joint first Solder provides permanent corrosion protection Do not rely on solder to provide mechanical integrity Tin the iron (apply solder), then wipe off oxide on the wet sponge Apply the clean hot iron tip to the joint When the joint is hot, flow in the solder to the joint, not to the iron