RE: Lipo vs. Nicad?
OK, from someone who uses lithium ION batteries in all his jets let me give you the other side of the facts.
Yes, LIPO and LI-Ion have to be taken care of or they can catch fire. Usually what happens is somebody is fast charging them or charging them with the incorrect charger and something goes wrong. I have been using duralites in my jets and my TX now for almost 18 months. I charge them in my trailer and have never had anything go wrong because I use the suggested charger for them and nothing else.
Yes, depending on the application that you are using them for you can fly for almost 2 months without recharging. A club member that I fly with substituted a 4800 mah 4 cell lithium ion battery for his 1100 mah nicad on a trainer. The current draw on that airplane is almost nothing (4 standard servos) and he can fly 3 -4 flights a week without having to recharge for almost 2 months (5.1 volt regulator on the RX also).
No, if you are going to put them in a very high current drain airplane it would be wise to charge them after every flying session.
Yes the Li-Po are more sensitive to shock than others as they are a soft shelled battery where as Li-Ion's are packed in a metal can that can take a little more abuse. If you are going to use them, I would go with Li-Ion and protect them in the aircraft the same way you would protect nicads.
There are alot of people out there using these batteries and if they were so dangerous you would hear about more problems with them than just the occassional, "My garage caught fire story." I would say 99.5% of the time you hear these kinds of stories it is user error and not the batteries fault. If that were the case you would see cell phones, pda's, laptops, handheld kids games, etc exploding and catching fire all over the place. The reason you don't is that the manufacturer gives you a charger to use and if you use the correct charger nothing goes wrong.
This is just my .02 worth. Like I said I have been using them for 18 months now and I love them. If I thought they were unsafe I would not trust my $7K jets to them.