Lithium Polys are safer than the old Li/Ions
The polymer is supposed to make them handle higher charge rates without overtemping and contain gasses better if they are overcharged....ie, slower release of gas as opposed to outright explosion.
They are very popular with the Mini RC crowd...being used to power 1/18th scale MiniT trucks to 40-50mph resulting in spectacular crashes. I've not heard of one exploding yet. I think the technology has come a long way.
Charge rates for the little packs run in the 1 to 2 amp range (about 1/3rd as fast as NiCds) with discharge rates way up in the 10 to 15amp range. This is for the tiny little 3 cell 11.1V 1,100mAh packs. Larger packs can handle 3-4 times that much current.
My Xray M18 which runs a 5,400Kv Mamba brushless with a Li/Poly pack will motivate around 45mph, geared for acceleration...not top speed.
Packs run in series and parallel. Parallel for more energy storage. Series for more voltage. 3.7 volts per cell. A typical 11.1V 3 cell (often designated as a 3S for 3 in series) Li/Poly pack is much lighter and smaller than a 8 cell 9.2V NiMh pack.
Last edited by Disaster; 10-01-2004 at 07:17 PM.