Kerry Wan/ZDNET Follow ZDNET:  Add us as a preferred source  on Google. ZDNET's key takeaways Adaptive charging aims to reduce battery wear by keeping charge speeds low. The Anker Nano 45W is the best adaptive charger available. You could get most of the benefits by using a low-power charger for overnight charging. Whether you're using a cheap $10 charger or something that costs an awful lot more, the modern USB charger is simply an amazing bit of tech. It may look like just a box plugged into a wall outlet with a cable going to another box. But behind the scenes, there's a lot going on.  The moment you connect a charger to your device -- whether it's a smartphone, tablet, laptop, or power bank -- the charger wakes up, and the two gadgets quickly negotiate the best and safest voltage and current combo to use before getting on with charging.…