Probably not enough, or not the right things to know. It’s not your fault, it’s that you were used to the memory effect of NiCads [nickel-cadmium] or NiMHs [nickel-metal-hydride]. Those batteries didn’t like to be recharged until they had reached near total discharge. If you topped them off they would “remember” that and soon could only be recharged to the point where you started to recharge them. Over time each charge got shorter and shorter until the battery became useless.
Smart phones and laptops use lithium-ion batteries, or Li-ion. These batteries do not have he dreaded memory effect and you can safely top them off anytime. In fact, Li-ion batteries will actually last longer if you regularly top them off when they still have a lot of charge left. Topping off a Li-ion still at 70% charge is actually good for it.
For a treatise on how Li-ion batteries work check out this article in Popular Mechanics. I found it fascinating. Basically, anode throws a big party for a lot of guests and when things get crowded they all want to depart for cathode’s house, where they proceed to drink and make merry as a result of you turning on your portable device. After a while some of them want to go back to anode’s place to sleep it off, but the party will be over if too many of them leave cathode’s. So you put a halt to the migration by putting your portable device on the charger and the guests begin to sober up and return to cathode’s where all the best action is happening. The party continues until all of the guests are too pooped out to party any longer. That should take about 2,500 trips back and forth between anode’s and cathode’s. If not too many guests are allowed to be at anode’s for too long the party might last even longer.
I just noticed my iPhone battery is at 64% charge, so I better go put it on the charger.