Charging iPad With Less Watt Prolong Battery Life?

With the exception of some very old models of iPad, iPad devices require a Power Adapter of at least 10-12W (i.e. 2.0-2.4A @5V) the charge. When attempting to use a 5W Power Adapter, your iPad Air M2 will be drawing power from its internal battery.

Your iPad will automatically optimise and regulate battery charging. When using a compatible USB-C Power Adapter, the iPad will only fast-charge to approximately 80% of its maximum capacity, beyond which the iPad will substantially reduce the charging rate to protect the battery.

Good-_-Advisor wrote:

With a 5W 1 amp, I maintained my iPhone 14 Plus at 100% for 10 months.

That most likely indicates some sort of issue in the measuring of the battery health. It is unlikely that the battery actually retained 100% capacity for 10 months unless you never used the phone.

Apple, AFAIB, promotes faster chargers for faster battery health depletion.

Or, you don't completely understand how batteries work. Something to consider.

Turn on optimized battery charging and charge the phone every night (so that it backs up automatically). Unless something goes seriously wrong, the battery will last you about 2 years. At that point, you decide if you want to replace the battery (fairly cheap at 10% of the cost of a new phone) or buy a new phone. Don't waste your time and cognitive energy trying to micromanage batteries. No matter what you do, they will always degrade. It's just physics.

When to charge your iPhone or iPad - Apple Community

You're very welcome.

Good-_-Advisor wrote:

Thanks Idris, much appreciated.

Best of luck!