Some lithium technologies are more tolerant than others. Paraphrased from http://www.candlepowerforums.com/vb/showthread.php?317698-Lithium-IMR-vs-ICR-vs-IFR:

ICR == LiCoO2 == What most people think of when they say "Lithium Ion batteries" == can be prone to "venting with flame" when violating the loading specs. Be sure to use high-quality, protected cells.

IMR == LiMn == Good for high-drain use but has less capacity == Can overload but significantly less likely to go into thermal runaway and also less likely to hurt you or your equipment if it does. Always use high-quality cells, nobody makes them with PCB protection as far as I can tell (because you don't need it).

IFR == LiFePO4 == Longer cycle life, better power density and safer than ICR, needs a LiFePO4-aware charger in order to charge safely. Be sure to use high-quality, protected cells.


Most of my rechargeables are NiMH or ICR, but I do have some IMR cells for specific applications. I also only buy high-quality cells and use a high-quality charger.