Editing Psion Revo General Maintenance (section)

== ⚠️ Charging rules ==

These are the habits that determine how long a Revo's cells last, and they are unusual enough to be worth learning deliberately.

* '''Do not put the machine on charge when the battery is already above about 80 %.''' The charge termination depends on sensing a thermal change that occurs around that level. '''Missing that thermal change can and does lead to overcharging.'''<ref name="wprevo" />
* '''NiMH cells only.''' Because of the way the charging circuit works, no other chemistry is recommended.<ref name="wprevo" />
* '''The red charging light turns off at around 84 %''', not at 100 %. That is normal; it does not mean charging has finished.<ref name="wprevo" />
* '''After any cell replacement, and after a hard reset, charge uninterrupted from 0 % to 100 %''' — about six hours for stock 700 mAh capacity, preferably with the machine switched off — so the hardware can recalibrate. Ignore the battery meter during that first charge.<ref name="wprevo" />

Put plainly: '''let it run down properly before charging, and let the charge finish.''' Topping a Revo up constantly is the worst thing you can do to it.