About an hour and a half. It will charge them at a one c rate untill it is at about 90% and then it will charge the last 1% at like a .1 c rate. The astro flight 109 will charge them faster, it will charge the packs at a faster rate then the ice once it hits the 90% capacity. I have also heard that the ice some times doesn't fully peak the packs. If you are going to start running lipo I would sale your ice and pick up a 109 and a balancer.