Maybe doesn't belong here but I'll try.

From another RC site I acquired some data relating pack voltage to "State of Charge" for Lipo's, only 7 data pairs. I'd like to find an on-line program (I don't have Excel) that would let me plot this data with useable resolution and accuracy. It might be useful when flying electric and estimating remaining useable flying time. Any ideas where I could find such a program?

Thanks

Frank