Months.

If you're not going to run them when you charge them use storage mode and put them back where you had them stored. Everything I read asys its bad for life to charge lipo to 100% and then just leave it that way.

I had some puff I left for almost 3months when I had to go out of country on business and stayed way longer than I was told I would have to. Those had been left at 50%. I don't use 50% anymore, but 60-80%, usually 80%.