I've owned both a 969 & 977 and used them to charge both lithium ion and lithium polymer batteries. In fact, I bought the 969 back before lithiums became popular because it was one of the few chargers that could charge lithium packs. My friends and I found that as long as you monitored everything correctly and used the correct charge settings, there were no problems at all. However, if you want to be safe, I would suggest investing in a higher quality charger. I've also owned an ICE, Triton, Triton 2, & Hyperion EOS0610i Duo chargers. I would suggest spending the extra for one of these. The Hyperion EOS0610i (solo charger w/ built-in power supply) looked pretty good for the money as well as the new Venom Pro Charger (this one is cool because the charger and power supply are so compact).