Post by thread:lithium-ion batteries

Sorry for the off-topic question, but does anyone know how lithium-ion batteries(such as laptop batteries) like to be treated? Do they prefer to be kept charged, like lead-acid batteries, or do they prefer to be cycled deeply, like nickel cadmium or nickel metal hydride? I realize there's a sophisticated charge controller chip handling things, but if a change of my habits can effect the lifespan, I'm interested(I'm also superstitious when it comes to rechargeable batteries). Thanks, Bob

At 23:19 8/01/97 -0800, you wrote: >Sorry for the off-topic question, but does anyone know how lithium-ion >batteries(such as laptop batteries) like to be treated? Do they prefer to be >kept charged, like lead-acid batteries, or do they prefer to be cycled >deeply, like nickel cadmium or nickel metal hydride? I realize there's a >sophisticated charge controller chip handling things, but if a change of my >habits can effect the lifespan, I'm interested(I'm also superstitious when >it comes to rechargeable batteries). > >Thanks, Bob Stick to NIMH batteries, they last longer but get cooler when full charge is reached so be carefull if using delta t charging. Gordon > > Gordon \\\|/// | ~ ~ | ( @ @ ) ----------------------------oOOo-(_)-oOOo-------------------------------------- It wasn't me.

Gordon wrote: >Stick to NIMH batteries, they last longer but get >cooler when full charge is >reached so be carefull if using delta t charging. Sorry, but this is misinformation. The charger actually relies on the rising temperature of NiMH batteries for charge termination. This is called the dT/DT method, which basically is, charge termination at 0.8 degree C / minute. NiMH can reach as above 70 degree C if overcharged. Operating spec is supposed to be no more than 55 degree C. NiMH is also more sensitive to high temperature damage than other batteries. Basically the hydride gets boiled off if overcharged. However, NiMH is still a good choice as recently Toshiba introduced a new type of NiMH with potentially twice the capacity of Li-Ion pound for pound. Peter Tiang spam_OUTtiangcfoonTakeThisOuThitachi.com.my

Bob Blick wrote: > > Sorry for the off-topic question, but does anyone know how lithium-ion > batteries(such as laptop batteries) like to be treated? Do they prefer to be > kept charged, like lead-acid batteries, or do they prefer to be cycled > deeply, like nickel cadmium or nickel metal hydride? I realize there's a > sophisticated charge controller chip handling things, but if a change of my > habits can effect the lifespan, I'm interested(I'm also superstitious when > it comes to rechargeable batteries). Dear Bob: Li-ion batteries don't care when you charge them; do it when convenient, and don't worry about the procedure. They are sensitive to overcharging, so some equipment manufacturers are saying you should disconnect the charger after reaching full charge, but this is just in case of failure of the protective circuitry. (Early Li-ion batteries were subject to catastrophic failure modes.) Motorola recommends leaving their cell phone batteries in the charger whenever they aren't in use; Toshiba says try not to charge too long. Despite news to the contrary, Li-ion cells are your best bet for the next few years. There was a pretty good article in a recent EDN (Dec. 5, pg. 179) with a good sidebar on construction and history. EDN has a web site at http://www.ednmag.com. -- Tom