Guidelines on Safely Charging Lithium-ion batteries for cordless equipment

Simple Guidelines for Charging Lithium-based Batteries

As we use more & more battery powered appliances, tools & devices it is important to understand a few common safety tips for safe battery usage, especially when it comes to charging. 

• A portable device should always be turned off while charging. This allows the battery to reach the threshold voltage unhindered and reflects the correct saturation current responsible to terminate the charge. A parasitic load confuses the charger. 
• Charge at a moderate temperature. Do not charge below freezing. 
• Lithium-ion does not need to be fully charged; a partial charge is perfectly OK. 
• Chargers use different methods for “ready” indication. The light signal may not
  always indicate a full charge. 
• Discontinue using charger and/or battery if the battery gets excessively warm. 
• Before prolonged storage, apply some charge to bring the pack to about half charge. 
• Over-discharged batteries can be “boosted” to life again. Discard pack if the voltage
  does not rise to a normal level within a minute while on boost.
• ALWAYS turn off your charger at the wall when finished charging - this prevents wastage of electricity, PLUS reduces the chance of overheating the charger or battery to the point where it becomes damaged. Look around your house & see how many tool & device chargers are plugged in but not charging anything. In this mode they are just little heaters, wasting electricity, but also in the long term potentially cooking the electronic controls in the charger itself. This can lead to a damaged charger feeding too much current into a lithium ion battery & not turning off when it should. This is very dangerous.
• Only use genuine chargers to suit the brand of battery/tool you have - don't be tempted to use aftermarket chargers as these may damage the battery to the point where it can be dangerous to use
• Avoid periods of intense use followed by immediate charging as you can super heat the lithium ion to a dangerous level
• DO NOT purchase machinery that is under powered for the job as this can cause battery or motor over heating