How to drain a battery

This is in the faq for the LiFePo4 batteries I got.

How does lithium’s shelf life compare to that of lead acid? Unfortunately, lead acid batteries deteriorate unless you charge them every day. Lithium maintains most of its usable capacity even if you store it without charging for a year. For optimal protection, experts recommend storing LiFePO4 batteries at 50 percent depth of discharge (DOD)

I will answer the portion of how to drain a battery. The next time you blow out a 12 volt car battery (providing it is a conventional light) pop it out, odds are it is the low beam that died, which means the high beam should still be good. Wire up a negative and a positive  wire to the High beam terminals and let it suck the battery dry, if that is what you want to do. Put the bulb somewhere it is safe to store it (heat may cause an issue, and no one wants a fire).