In the long-term, it's better not to charge the device t0 100%.
Microsoft says you can use 5 cycles a week for 4 or 5 years before your battery only holds 80% of original capacity.
If you want the device to last longer, then charge it to 90% and unplug it. You could also charge to 80% and unplug it, or even 50% and it will live longer, but then it will likely run out on you, so you need to find your own sweet spot between long-term and short-term battery life.
Personally I charge the device at night before I sleep and I charge it to about 90%. I'm not too worried about it because in less than a year I'll probably have a SP4.
For comparison, I charge my phone without a care in the world as the battery is easily replaced, however I don't upgrade phones like I do computers, I just don't really care about having the greatest phone.