Reference Manual - Segway

Storing Your Segway PT
To maximize the performance of your Segway PT Batteries, fully
charge your Batteries for at least 12 hours, once a month, or after
every 12 hours of operation—whichever comes first. Charge your
Batteries only when they are within the specified charging
temperature range.
Store your Segway PT (and its Batteries) indoors, in a place that is
free of moisture, humidity, and temperature extremes. Even if you will
not be using your Segway PT for an extended period of time, you
should leave it plugged into AC power. Otherwise the Batteries could
fully discharge over time, causing permanent damage.
Store your Segway PT within the recommended charging and storage
temperature ranges, as shown in Table 10 on page 63 to preserve
the full performance capabilities of the Segway PT Batteries.
CAUTION
Failure to charge the Batteries could result in permanent damage to
them. Left unplugged, the Batteries could fully discharge over time,
causing permanent damage.
Use only charging devices approved by Segway.
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