Order of the Bath

These are the sort of rechargable batteries found in laptops, power tools and many cameras and mobile phones. They have different characteristics to the well known Nickel-Cadmium (NiCad) rechargable and need to be handled differently. The information for this post comes from Battery University.

• They only have a life of about 300-500 discharge/recharge cycles so expect to have to replace them at some time. In normal use this will be 2 to 3 years or longer for low current applications.
• Unlike NiCad, the battery prefers partial rather than full discharges.
• However, batteries with internal calibration gauges, such as those in laptops, do need to be recalibrated occasionally so that the gauge knows the actual capacity. They should be discharged to the cut out point on the equipment about once in 30 times (and recharged immediately so they don’t drop below this base).
• For storage, a half charge is better than a full one (and keep it cool).
• Check the manual, but it is often better to remove the battery from a laptop if running from a reliable mains supply. The worst scenario for a Li-ion battery is fully charged and hot, a typical situation for a mains powered laptop.
• Overcharging is not a problem as they cut out when full.
• They have a limited shelf life even if not in use, so check dates of manufacture and don’t stock up in advance of requirements.
• Beware of counterfeits—some without adequate protection circuits have been known to explode. In fact some branded ones have had problems as well.

This entry was posted on 10 Jan 2006 at 09:39 by Rick and is filed under Technical. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.