If you're going to purchase a cordless tool, then you should really think about getting one with Lithium ion batteries. They cost more, and it's easy to think you could just buy a cheaper model and get a spare battery, but it's not the same. Lithium ion batteries are a true hassle free solution.
When you do something processor intensive, plug in the charger. Not only because this usually triggers a higher performance setting and give you more horse power to play with, but because when the battery is discharged at maximum rate it's more probable to overheat, and heat is a great enemy of Lithium-Ion.
Why is this important? If you have a relatively new PC the only problem you will get are error messages relating to the clock on start up. No big deal. If your PC is older then a low battery could be a nightmare. I had a PC which once lithium battery stocks every few months refused to boot. Rather than take the PC in for repair or start replacing parts myself the first thing I did was look at the BIOS settings. It was soon obvious that the BIOS settings were corrupt (wrong bus speed). I put a volt meter on the battery and sure enough it was reading 2.2 volts.
These types of batteries also do not receive any damage if you use your phone while its charging. Older cell phones that used older types of batteries would damage the battery if used while charging. This simply is not the case anymore with the newer mobile phone batteries.
Another thing to remember is not to store those batteries in the charger as well. This will draw energy away too, and cause your battery to die off sooner than you expect. Keep it away from high heat or extreme coldness. Heat tends to cause damage to your Lithium battery stocks while exposing it to low temperatures over a period of time will draw its charging capacity.
My.Vu offers the Crystal which is an elegant Lithium mines Ontario hand-free viewing eyeware device with earbuds and VGA resolution and a USB rechargeable battery with up to hours viewing time.
Laptop computer uses: If you keep the battery in your laptop for everyday use, and power it from the wall socket, unplug the power every few days and let it run off the battery, as a battery at 40% capacity lasts longer than one at 100% capacity. if you don't travel with it, you should remove the laptop battery when on fixed power.
With government incentives, the cost of one of these EV's can be reduced to a more acceptable range, keeping the cost closer to a conventional gas vehicle. There are also reduce maintenance costs with an EV, no oil changes and the electric motors are mostly maintenance free.