The protective shell can be only the bottom side which replaces the bottom of the case. The internal laptop batteries are quite safe to handle if you don't use anything sharp on them. We let people handle phone batteries for ages and they weren't nearly as protected as those old laptop battery tubes.
They were certainly more protected than the almost naked ones I see right now which I can singlehandedly bend (but won't given the fire hazard). And not LiPol batteries too, which are super nasty in that regard: the more energy-dense the battery is, the more of a hazard.
