stumbledin
+1y
one= BATTERY
plural= BATTERIES
That being said...
An Optima or ANY gel BATTERY is not meant to EVER be drained fully dead. If you let it go completly dead and leave it like that for a few days, it will never be the same. If you drain it dead, charge it as soon as possible.
The thread asks for the best BATTERY'S, and so the question is which BATTERIES are the best. Kinetic seems to be a very good BATTERY, and the Optima line is a very good series of BATTERIES. like I said, you cant run them dead.
On another note, most small independent BATTERY shops will sell you a generic gel BATTERY. Its the same as the Optima, just without the name.