How long can you safely leave a Lipo without using it
 

As the title says i left a Lipo for a about a month without recharging it after use and went to charge it and it worked which made me think how long can you leave them if you dont do the discharge thing

Always charge or at least half full when storing or leaving for a while - that way you will be fine - a lot more than 1 month if left with charge in it

I left mine for 9 months, but they are older spec ones, i heard new lipos don't like that.

Self discharge on a lipo is so small it is not worth worrying about. Best practice with lipo especially the latest generation is to charge it just before you use it.

Normal storage voltage for lipo is 3.85v per cell although i have experimented with leaving lipo stored for extended periods at 4.1v per cell. The lower the voltage you store them at the lower the cell degredation is. At 4.2v per cell the degredation is at its highest.

If storing for a couple of days 4.1v per cell is ok but any longer than a few days i would recommend taking them to storage voltage. If you want absolute maximum life from your lipo always store at 3.85v per cell. Charge just before you use it and set your LVC to 3.5v per cell.

There are a few other ways to extend the life of your lipos by a very large margin but these methods are not really practical for RC use. I have a lipo i have been doing an ongoing experiment on with over 200 cycles on it and it has still got almost identical Ri and capacity as when it was new.

A long time but leave at half charge not full!

so what happens if it reads low voltage when i plug it in

should i charge it the nicad way to get the voltage or not