Thats a A123 battery I keep those in my glove boxes in all my cars will jump start a dead battery and very safe the just have weird voltages that we really can run in rc but a few of my Larger quads and airplanes do ..they are 3.6 volts fully charged..There was the main factories in cities...
I have always stored my Lipos at . 3.7 to 3.85 volts a cell. I use a numbers of dischargers some home made others modified from Nixx days. Leaving a lipo fully charged is a dangerous thing to do.It leads to swelling and can cause a fire