From my point of view (as the technical manager of a company that manufacturers lithium polymer cells), all batteries consisting of lithium polymer cells should have a protection circuit for both over chare and over discharge. The cells should also be inside a plastic case to protect them from physical damage. The "hobby" argument does not work for this technology.. it is far too volatile.
Lithium polymer cells (like lithium ion cells) do not like being overcharged. They contain highly active materials and a non aqueous flammable electrolytes Charging cells >4.2V can be dangerous and this is what can cause them to explode during charge. Over discharge is more of a performance issue rather than a safety one.
I think that high drain cylindrical lithium ion cells would be a better long term move rather than lithium polymer. A cell size of 26 dia and 70mm length is emerging as the new standard for high drain lithium polymer cells - these are 3.7V and 3Ah, capable of 30A drain rates - they are currently being designed into professional power tools (the market that drove the development of the high drain capable NiMH cells we are using today)
And to cap all of this.. if you modify any lithium ion or polymer battery in any way.. you CANNOT take it upon an aircraft.
I will stick with GP4300SCHR for now... although i am currently working on a design for a 24V 3Ah lithium ion battery for power tool applications... no that will have a kick!
Neil
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