I run my packs twice a day all the time.
Just make sure you let the cells rest between runs. They should be cool, and have at
least two hours rest. The cells often feel "cool" on the outside after sitting for 30minutes, but they are still warm on the inside.
For a while, I was getting by with 2 Nicad packs, not something i would suggest, as the cells don't get enough rest time. I would suggest at LEAST 3 packs. Four is nice to have.
Let the cells rest, and you should be fine.
