The complete guide
How long does 55 hours of battery actually last night to night?
A battery figure like "55+ hours" is easy to skim past on a spec sheet, but translated into actual nights and naps, it changes how often you think about charging at all.
Turning hours into nights
If a typical night runs 10 to 12 hours of continuous play, plus a couple of daytime naps at an hour or two each, you're looking at roughly 14 hours of real-world use per day. At that rate, 55+ hours comfortably covers close to four full days before a recharge is needed, which is why this machine tends to get charged on a loose weekly schedule rather than plugged in every single night.
Why this matters more for travel than for home use
At home, charging nightly isn't really a hardship, the machine is probably near a socket anyway. The real benefit of a long-lasting battery shows up during travel: a weekend away, a hospital stay, or several nights at a relative's house where finding a spare socket isn't guaranteed. Knowing the battery will comfortably outlast the trip removes one thing to think about while already juggling everything else that comes with being away from home.
Don't let a long battery become an excuse to ignore it entirely
Even with 55+ hours available, it's worth building in a habit of topping up during the day rather than waiting for it to run flat, ideally while you're out and about or during a nap rather than overnight when you need it working. Treating a long battery life as "never needs attention" rather than "needs less frequent attention" is the one way to still end up caught out.
What the child lock adds on top
Long battery life solves one kind of interruption; the child lock solves another; an older sibling or a curious toddler pressing buttons and changing the sound or volume mid-night. Combined, the two features are aimed at the same goal: fewer unplanned interruptions to however many hours of sleep everyone's actually getting.