Lithium-Ion and Lithium-Polymer batteries actually like being charged often. Deep discharges do them more harm than frequent partial charges, so you're not doing anything wrong in that respect. Leaving the charger plugged in doesn't do the battery any immediate harm either: LiIon and LiPol batteries have rather sophisticated charging circuits built into them, to prevent overcharging, and the tablet has its own overcharging protection. If you were to leave the tablet plugged in for weeks on end, eventually something might go wrong (although the odds of a lightning surcharge are probably higher than the circuitry going haywire on its own), but your charging habits are perfectly okay. That said, LiIon and LiPol batteries have one drawback: They "age" on their own. From the moment it has been manufactured, a lithium battery starts to deteriorate and there's pretty much nothing you can do to stop that. Not using it will prolong its life (if you store it in a fridge, charged as close as you can get to 40%), but you have to agree the pointlessness of that strategy. Every charging cycle also shortens the battery's lifetime; originally, lithium batteries would last only 100 to 150 complete charging cycles, but they're now up to 300 cycles and more, with some users reporting 500 charging cycles. For simplicifcation you can add up partial charges (i.e. if you recharge your battery always at 50% depletion, it could last 600 charges or more); it's not exactly that, but close enough. So no matter what you do, depending on your use you still might have to buy a new battery every year. And, given what I wrote above, buying "spare" LiIon or LiPol batteries is not a good strategy -- as the spares will deteriorate -- unless you really need the extra battery regularly. For me, I found it better to invest in an external charger that takes AA batteries for the times when I need extra runtime. I have a 4 AA charger that will almost completely recharge the tablet's battery from 2500 mAh NiMh rechargeables.