I'll work this backwards....first off, if your parents are using Nexii 5, the Bolt is going to be a superb choice for them. Comparatively speaking, the battery life on the Bolt is worlds better than the Nexus 5. Actually, as a phone it blows the Nexus 5 out of the water in every category. Seriously. Your parents would be ecstatic.
Feel in hand is a lot like the iPhone 6/6S Plus.
I'm comparing battery life anecdotally to the LG V20 and iPhone 7 Plus - I get significantly less time (2-3 hours less) per charge on the Bolt than the other two devices with very similar usage patterns. For a "normal" user, the Bolt would probably last all day. I run businesses from my phone and consume a lot of media, so I think my daily usage is probably significantly above average. Not to mention I am rarely on WiFi simply because the places where I work often don't have it.
So, to sum....compared to other modern smartphones that are similarly sized and equipped (like the LG V20 and the iPhone 7 Plus), the Bolt is just not quite up to bar from a battery life standpoint. But for the average user, I doubt it'd be noticeable and I suspect the phone would still last a day for the "average" user. Further, the Bolt's many other attributes far and away make up for slightly reduced battery life. I've been very pleasantly surprised by this one, and I was already a raving HTC fan.
Hope this helps and it's not just a bunch of rambling. I've had 1.5 hrs of sleep over the past 50 hours.