androidbatteryiphone
When I'm at my desk and using my smartphone, it is better to keep it charged or discharged?
If I use it while it's discharging I will use up my charge cycles?
Obviously this would be subjective to the smartphone model I'm using, but generally speaking from a li-io battery point of view?
Does the iPhone offer a better charging/battery lifespan efficiency?
You do not need to disconnect your MacBook Pro's battery. Your battery will stop charging once it is full. Apple's modern batteries are much smarter than previous designs.
To get the most out of your MacBook Pro's battery, follow the Notebook Battery advice from Apple: unplug and use your battery until empty about once a month, then charge back up to full.
At the time of answering, Apple's advice read:
For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her notebook on the train, then plugs it in at the office to charge. This keeps the battery juices flowing.
If you need help following Apple's advice, use Battery Guardian; it is free and will remind you when to deplete your battery.
Deeper discharge/charge cycles shorten an Li-Ion battery's lifespan faster that shallow ones. (e.g. One 100% cycle is more wearing that four 25% cycles, etc.) Therefore, keeping an iPad or iPhone on a charger or always topped off between short uses will tend to lengthen the battery's total lifespan by reducing the number of deeper cycles per annum, all other thing being equal (such as total time of use).
"Calibrating" has almost nothing to do with the battery lifespan. It's mostly needed to help the battery gauge icon behave more accurately. Once or twice a year is probably good enough for that purpose.
Best Answer
This questions risks inviting a lot of opinion, so some may vote to close this down.
However, to try and keep this to the facts, I refer you firstly to what Apple has to say about their batteries. You should also read this.
In a nutshell, the key indisputable points are:
Also, the latest research confirms one of the most important determinants of what ruins a battery is time. (You could purchase a brand new iPhone battery and leave it unused in its original packaging for five years and then find it's capacity is nowhere near what it should be when you start using it)