I have a riding buddy that has one in his 2010 EG. He likes it, never had a problem.
That said, I fly R/C planes and they use these batteries. If you drop below 3 volts per cell, it ruins them. Overcharging, ruins them. Under voltage, overcharging, physical damage and things simple as age can cause a fire. It's a very violent chemical fire, too. Go to YouTube and search "LiPo Battery Fire".
Yeah, I know, it's not the same thing, but It Is the same chemistry, and not a risk I'm willing to take. I have no intention of starting a debate, if you want to run one, nothing will likely ever go wrong. I'm just fine with old fashioned lead acid batteries. Keep them on a trickle charger if you're not riding for awhile, and they will last many years.
I hate that motorcycle they make me ride. I'm here to tell you there ain't nothing in the world I hate worse than that elephant under my ass.
Officer John Wintergreen reference his Electra Glide.
-Electra Glide in Blue, 1973-