Let me start with.
"DON'T DO THIS IF YOU DO NOT KNOW WHAT I AM TALKING ABOUT"
Now that that is over!! Ha!!
Have you ever wanted a good source of cheap batteries for your models?
Well look no further than an old laptop battery pack.
Nine times out of ten when a laptop battery dies it is from one or more of the cells dropping out.
The protection system in the laptop will not know the difference and will not charge correctly.
If you take apart the battery pack and measure the cells you will normally find only one or two are bad.
The rest can usually be cycled back to a usable condition.
You will not get 100% out of them but as most lithium ion batteries are normally 2500-5000 MA you can get a good run time out of them.
The cells are rated at 3.7V just like the Lithium Poly cells but are a hard case battery.
Obviously working with batteries and battery packs requires you know something about them first.
So I don't recommend this for anybody that is clueless as to what I am talking about.
As the Mythbusters say, "Don't try this at home, we are professionals"
I will not get into what is involved in scrapping a battery for cells.
This is just to let you know they are out there, and a good source. BD.