RE: A123 Question
I've continued to use Lithium-ion batteries because monitoring their capacity is a quick and simple procedure that can be performed with the voltmeter in my field box. Lithium-ions are reliable, lightweight, have good longevity and are safe to charge in the plane. Remember, many electronic devices that we use in our homes have Lithium-ion batteries such as cameras, laptops, phones, universal remote controls, iPads, etc., etc. and the batteries are charged without removing them.
I never have to charge at the field because I never have to guess how much of the charge remains as one has to do with A123 batteries. A123 batteries are great for DeWalt power tools since there won't be a disaster when the battery suddenly quits.
By the way, A123 Systems Inc. has failed because they were turning out bad batteries. They will go completely out of business if the government rejects the huge bail out offer by a Chinese company. Who knows, you may be using some good Chinese batteries soon