Editing Psion Revo Troubleshooting Guide (section)

== Step 1: battery and charging ==

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Battery and charging faults'''
! Symptom !! Cause !! Action
|-
| '''Runtime collapsed; will not hold a charge''' || Worn NiMH cells. Original stock is '''700 mAh''' and dates from 1999–2003 || Replace them. See [[Psion Revo Battery Replacement]].
|-
| '''Dies intermittently; resets for no reason; will not charge''' || '''The battery connector working loose.''' Original Revos suffer from '''batteries coming loose and unplugging''' — '''fixed on the [[Psion Revo Plus|Plus]]''' || Open the machine and secure the connector with hot-melt glue or silicone. Not superglue.<ref name="wprevo" /><ref name="r3uk" />
|-
| '''Battery meter obviously wrong''' || The hardware has not been recalibrated || Hard reset, then '''charge uninterrupted from 0 % to 100 %''' — about six hours at stock capacity, preferably switched off. '''Ignore the meter during that charge.'''<ref name="wprevo" />
|-
| '''Red charging light goes out well before full''' || '''Normal.''' It turns off at around '''84 %''' || Not a fault.<ref name="wprevo" />
|-
| '''Cells get hot; charge never terminates''' || '''Overcharging.''' Charge termination senses a thermal change around 80 %; if the machine is put on charge above that level the change is missed || '''Do not charge either Revo model when the battery is already above about 80 %.'''<ref name="wprevo" />
|-
| '''Charges erratically after a cell replacement''' || '''Damaged thermistor.''' A strip of circuit ribbon wrapped in with the cells acts as the temperature sensor || It must be intact and '''held against the cell body'''. Rewrap the pack correctly.<ref name="r3uk" /><ref name="wprevo" />
|-
| '''Replaced cells behave oddly''' || Wrong chemistry || '''NiMH only.''' The charging circuit is designed around it.<ref name="wprevo" />
|-
| '''Fitted higher-capacity cells and the charge seems short''' || Expected || Work out and extend the charge time proportionally.<ref name="wprevo" />
|}