I have a lipo battery that when I try to charge it I get a low voltage error. Does that mean the battery is no good.

That's most likely means you drained one or all of the cells too far. Do you have a voltage checker to see what each cell is sitting at?

No I bought the battery from somebody. I can get a voltage checker what do I do?
Thanks

sometimes when this happens you can charge the battery in nimh mode to bring the voltage up to correct charging specs, then switch to lipo mode to charge the battery as normal.

Well with the voltage checker you can confirm which cell is over discharged. Then you can do as said above and do a slow charge in Nimh mode up to around 7v then try to balance charge them again

The only other way you might get that same charge error is if you forgot to connect the balance plug as well as the charge plug.