Until new nano lithium technology comes in later in 2009, mobile phone batteries are still notoriously flaky. Just when you need to make an important call the battery indicator tells you the charge is all but extinct. You may have conditioned your battery in line with all of the advice and old wives tales floating around but still have to re-charge yours every day. Short of buying a spare and keeping that charged what can you do?
The basic rule of getting a replacement battery is that it should have the same voltage as the original. An 18V drill cannot run on a 12V battery. It can only run on a 18V battery. The other thing is that the physical packaging of a battery can be different from company to company. A 12V Ryobi battery may not fit into a 12V Makita cordless drill unless the battery has the right physical dimensions. So make sure the replacement battery looks the same as the old one before you order it. Also, if you are looking for a replacement battery of the same voltage rating and by the same company, know that battery technology is changing rapidly. An 18V lithium-ion battery has a different physical packaging than a NiCad 18V battery.
Use cobalt mine the battery. Li-Ion safety circuits do a lot of great things to keep it in good condition, but they're going to go south if you don't use them. There is no wonder they're stored charged to half-capacity. If you most often use your netbook using AC power while you're at home, make sure that you let it run to the point where windows gives critical battery level warning at least two or three times a week.
2) Battery freshness: often overlooked. Always make sure you have the freshest battery possible. A battery can lose it's ability to hold a charge as time goes on. You want batteries that move off of shelves quickly to be sure they aren't old.
People know that communication is very important and there will be times when the batteries of the cellphones are drained and there are no outlets in sight. At least with cheap cell phone batteries the owner can stock up and put these to their cellphones and make those Lithium battery stocks emergency calls.
External effects can be a radiator in your room or direct sunlight, or just simply a mind boggling ambient temperature. A Lithium mines Ontario-ion cell loses 20% of its maximum capacity in one year when it's stored on 40 degrees Celsius and full charge. Not too many people have 40 C in their room all year long, but what about internal heat sources? If you use your notebook from AC power, you're keeping it fully charged, which it doesn't fancy, and on about 40C.
Don't empty the battery completely. Modern safety circuits take care of this, but if you take it to 3% capacity, then leave it like that for three months, it's most probably going to be damaged and lose some of its maximum capacity. If you have to store it for a while, charge it to 60%, and leave it like that in a dry and cold place.
Another one of the best drills out there is the Panasonic EY7540LN2L model. It makes fastening jobs a cinch. It is lightweight, and ergonomic. It is extremely easy on the wrist and hands, so it is comfortable to use. It has long lasting lithium batteries for longer jobs. It is an impact driver, and is definitely versatile. It costs more than the other two drills, but it is still one of the best. Overall, any of the drills mentioned above would be a great cordless drill to own.