Is It Ok To Leave Your Steam Deck Plugged In Overnight?
Ever since the concept of chargeable batteries was introduced in personal electronics, there's been a bit of a persistent misunderstanding about them. Rechargeable batteries last longer than typical batteries for the obvious reason, but that doesn't mean that they last forever. No electronic device lasts forever, unfortunately, and despite the passage of time, rechargeable batteries still need to be treated with a certain degree of care in order to maximize their potential lifespans and charge capacities.
Case in point, the Steam Deck, a portable computing powerhouse that it may be, uses a rechargeable battery (a 40Wh battery, to be specific). As with other portable electronics like phones or game consoles, there are certain practices you should be wary of if you want this very expensive device to last more than a few years. For example, if you want to recharge your Steam Deck's battery, is it safe to leave it plugged in overnight?
Steam Deck battery health
Valve has not released any concrete statements on whether or not it is safe to leave your Steam Deck plugged in overnight. However, according to the users on the Steam Deck forums, the general consensus answer is "Yes, but don't make a habit of it."
Like other similar portable electronics, the way the Steam Deck's battery recharges is that it powers up to 100%, then internally disables the power cable connection. That connection stays disabled until the battery percentage decreases on its own to 90%, after which the connection starts back up. If you leave the Steam Deck plugged in like this for long stretches, i.e. overnight, it's going to do that little back and forth over and over for hours on end. That kind of short-span charging and depletion will cause unnecessary wear and tear on the battery, shortening its overall lifespan.
Naturally, the usage of the battery will depend on what you're actually doing with the Steam Deck. For instance, if you're actively using it while it's plugged in, then the console will just draw power from the outlet, and the battery won't be affected. If you're planning on leaving the console for multiple days, though, then you should unplug it and power it down completely. Generally speaking, if you're going to use your Steam Deck multiple days back-to-back, just leave it in sleep mode overnight. It'll lose a little charge, but you can just charge it while you're using it.