Monday, March 06, 2006
All about battery!!
This is imporant... why?
Because each battery is finicky in its own way.
Alkaline holds a large charge but you have to throw them out. These are your typical AAA, AA, C, D and 9 volt batteries
Nickle cadnium was the 1st home rechargable battery. These also hold a good charge but they have a fatal flaw. They have a memory effect. A memory effect is when you charge a battery before it is completely empty. Lets say it is getting weak at 1/4 full and now you recharge it. You battery will now only charge up to 3/4's the way full and no more. A couple more recharges like this and your batteries will not charge at all.
Next and the most popular is a lithium ion. This is usually in cell phones, laptops, and if you look for them typical home batteries. They hold large charge for their size for slow discharging things like cell phones and have no memory effect. Charge them at any time and they will always charge to full. Unfortunately the age of the battery determines their fullness. At 1.5 years your lithium ion batteries will lose half their charge. That is 1.5 years after they are made not after you get the cell phone. So if your battery has been hanging out ina warehouse for 6 months you already lost a portion of your batteries life
The least popular batter is nickle metal hydride. It holds a decent charge and has zero side effects. Sure if it gets really old it will eventually die on you. You can also get these as rechargable home batteries.
Lastly is lead acid. This is a car battery. It has a large charge and puts out hundreds of amps at a time but it is huge and the chemicals inside are hazardous.
Now don't you feel a little more geekish?
Another critical consideration for lithium ion batteries is that they require internal controls. If one cell dies before the others, it's essential that the whole battery be deactivated until it can be recharged. Otherwise, some cells start charging others in a way that is very harmful for the battery. Basically all Li-Ion batteries have microcontrollers that execute this operation.