TED is a small nonprofit devoted to Ideas Worth Spreading. It started out (in 1984) as a conference bringing together people from three worlds: Technology, Entertainment, Design. Since then its scope has become ever broader. Along with the annual TED Conference in Long Beach, California, and the TEDGlobal conference in Oxford UK, TED includes the award-winning TEDTalks video site, the Open Translation Program, the new TEDx community program, this year’s TEDIndia Conference and the annual TED Prize.
You’ll find a lot of interesting movie inside, I personally like it, and truly contains Ideas Worth Spreading.
Invest your spare time to look around inside, I’m sure it would be time worth spending!
okay, I admit, on my first look, I didn’t really like it,
after watching the video, hmm, it doesn’t hurt to have one..
wow, anyone want to buy me one of this??
I know there’s a lot of rumors going on about how is the best way to maintain ur phone/laptop battery, some says “wait until the battery runs out then charge it, and immediately pull the charger when it’s 100%”, some say “charge it overnight”, some say “use it often, and charge it often”. Okay so here’s some tips and tricks I get from battery university:
Simple Guidelines
Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.
Batteries with fuel gauge (laptops) should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.
Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the battery at a 40% charge level.
Consider removing the battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)
Avoid purchasing spare lithium-ion batteries for later use. Observe manufacturing dates. Do not buy old stock, even if sold at clearance prices.
If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the battery at 40% state-of-charge.
Do and don’t battery table (BU22)
Each battery has unique needs that must be met to obtain reliable service and long life. The Do and Don’t battery table summarizes these needs and advises proper handling of each battery type.
Optimal handling may not always be practical in real life. Deviations from the ideal are acceptable but will lower the life expectancy of the battery to some degree. Exposure to heat may be the larger deterrent.
-
Nickel-cadmium
(NiCd)
Nickel-metal-hydride (NiMH)
Lithium-ion
(Li-ion)
Lead-acid
(Sealed or flooded)
Used in
Two-way radios, power tools, medical.
Similar application as NiCd; higher density.
Cell phones, laptops, video cameras.
Motorcycles, cars, wheelchairs, UPS.
Charging
Do run the battery fully down once per month; try to use up all energy before charging.
Do not leave battery in charger for more than 2 days because of memory.
Avoid getting battery too hot during charge.
Charge methods: Constant current, followed by trickle charge when full. Fast-charge preferred over slow charge.
Slow charge = 16h
Rapid charge = 3h
Fast charge = 1h+
Do run the battery fully down once every 3 months. Over-cycling is not advised.
Do not leave battery in charger for more than 2 days because of memory.
Avoid getting battery too hot during charge.
Charge methods:
Constant current, followed by trickle charge when full. Slow charge not recommended.
Battery will get warm towards full charge.
Rapid charge = 3h
Fast charge = 1h+
Do charge the battery often. The battery lasts longer with partial rather than full discharges.
Do not use if pack gets hot during charge. Check also charger.
Charge methods: Constant voltage to 4.20V/cell (typical). No trickle-charge when full. Li-ion may remain in the charger (no memory). Battery must remain cool. No fast-charge possible.
Rapid charge = 3h
Do charge the battery immediately after use. Lead-acid must always be kept in a charged condition. The battery lasts longer with partial rather than full discharges. Over-cycling is not advised.
Charge methods: Constant voltage to 2.40/cell (typical), followed by float held at 2.25V/cell.
Battery must remain cool. Fast charge not possible; can remain on float charge.
Slow charge = 14h
Rapid charge = 10h
Discharging
Full cycle does not harm NiCd. NiCd is one of the most hardy and durable chemistries.
Avoid too many full cycles because of wear. Use 80% depth-of-discharge. NiMH has higher energy density than NiCd at the expense of shorter cycle life.
Avoid full cycle because of wear. 80% depth-of-discharge recommended. Re- charge more often. Avoid full discharge. Low voltage may cut off safety circuit
Avoid full cycle because of wear. Use 80% depth-of-discharge. Recharge more often or use larger battery. Low energy density limits lead-acid to wheeled applications
Service needs
Discharge to 1V/cell every 1 to 2 months to prevent memory.
Do not discharge before each charge.
Discharge to 1V/cell every 3 months to prevent memory.
Do not discharge before each charge
No maintenance needed. Loses capacity due to aging whether used or not.
Apply topping charge every 6 months. Occasional discharge/ charge may improve performance.
Storage
Best to store at 40% charge in a cool place. Open terminal voltage cannot determine state-of-charge. 5 years and longer storage possible. Prime battery if stored longer than 6 months.
Store at 40% charge in a cool place. Open terminal voltage cannot determine state-of-charge. Prime battery if stored longer than 6 months.
Store at 40% charge in a cool place (40% state-of-charge reads 3.75-3.80V/cell at open terminal.
Do not store at full charge and at warm temperatures because of accelerated aging.
Store always at a full state-of-charge. Do not store below 2.10V/cell; apply topping charge very 6 months.
Disposal
Do not dispose; contains toxic metals; must be recycled.
Should be recycled. Low volume household NiMH may be disposed.
Should be recycled. Low volume household Li-ion may be disposed
Do not dispose; must be recycled.
_________________________ Created: May 2003, Last edited:March 2004
About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Vancouver BC.
Mr. Buchmann has a background in radio communications and has studied the behavior of rechargeable batteries in practical, everyday applications for two decades. Award winning author of many articles and books on batteries, Mr. Buchmann has delivered technical papers around the world.
Cadex Electronics is a manufacturer of advanced battery chargers, battery analyzers and PC software. For product information please visit www.cadex.com.
Yes!! Mozilla Firefox 3.6 is out, so what are you waiting for, upgrade your browser now.
Not that I hate IE, but I personally think that Firefox is way much cooler, along with the add-ons like firebug 1.5!
(note for web developer/designer, this firebug add-on is a MUST! blessed are those who create this add-on)
So if you are still using IE 6 or 7, do not, I repeat do not hesitate to upgrade to Firefox or Google Chrome!
sometimes what hinders growth is the resistance to change
