Alphasmart NEO User Manual page 141

hold a successively better charge each time until they reach full
capacity.
To charge the batteries:
Plug the AC adapter into a working electrical outlet and connect it
to the power port on the left side of your Neo.
To condition the batteries:
1. Fully charge your Neo with the AC adapter.
2. Use your Neo without the AC adapter until the low battery
message appears. (This may take 60–150 hours of use.)
3. Repeat steps 1 and 2 three to five times.
You'll get the longest life from your batteries if you wait for the low
battery warning to appear onscreen so the batteries aren't needlessly
recharged. Charging with the AC adapter for about 8–16 hours fully
charges it; if you charge it with an AlphaHub or USB cable, it may
take as long as 24 hours. Don't, however, charge the batteries for
more than a week. Doing so may damage the batteries.
Neo's indicator light turns green when the device is fully charged.
Storing and recharging Neos
Rechargeable batteries that aren't used over time "self discharge."
That is, they lose their charge and need to be fully charged again
before being used.
If the batteries self discharge too much while in storage (which can
happen if you store your Neo for longer than you intended), the
batteries themselves may become damaged, which in turn can
damage the device.
Important:
charge it before you store it, and then again after you take it out of
storage to compensate for the batteries' self discharge.
Understanding Batteries
If you're going to store your Neo for a month or longer,
Internal rechargeable batteries
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