Again, contrary to what you said. Different source.Periodically calibrate your battery.
Most batteries that have a “fuel gauge”, like those in laptops, should be periodically discharged to zero. This can be accomplished simply by letting your computer run until it reports a low-battery state and suspends itself. (Do not let your computer deep discharge, as I’ll explain in the next item.)
The gauge that measures the remaining power in your laptop is based on circuitry integrated into the battery that approximates the effectiveness of the battery’s chemical compounds. Over time, a discrepancy can develop between the capacity that the internal circuitry expects the battery to have and what the battery can actually provide. Letting your computer run down to zero every month or so can recalibrate the battery’s circuitry, and keep your computer’s estimates of its remaining life accurate.
And again, another source:
And again, another source:Charge often - Older electronic devices commonly used Ni-Cd batteries which benefited from deep cycling - allowing the battery to fully drain before recharging. Li-ion batteries on the other hand benefit from being charged often and early on in a fresh cycle. What this means is that a li-ion battery should be charged well before it is fully drained; think about when you plug your cell phone in to charge at night. You don't need to wait until the battery is running low to recharge it if it is a Li-ion battery.
Re-calibration - The exception to the above rule about charging is that about every 30th recharge or so, you should allow the battery to be nearly drained before recharging. This helps to re-calibrate the external battery meter on your electronic device. Your cell phone, laptop, or other device displays the amount of battery life left on it's display usually. Re-calibration ensures that your electronic device is giving you an accurate reflection of the actual battery life left since the last recharge.
Should I keep going?Fully charging and discharging actually taxes your battery more than if you charged it before full discharge. There is still room for full discharge before charging, though. If you do it once every 30 charges or so, you’ll not only keep your battery running longer, but you’ll keep your battery gauge properly calibrated. This is important, since an improperly calibrated battery gauge can lead to your phone being shut off while there is still actually a charge in the battery.
As for the charging, when has your iPad ever gotten particularly hot when leaving in plugged in? Mine shows absolutely no difference in heat whatsoever when plugged in. THAT is the danger of plugging it in over night, because exposure to heat shortens battery life...