xsto CT420SC Operation Manual page 33

NOTE: Don't start CT420SC while the battery is in charging.
4.1.1 Battery instructions and precautions
(1) Storage
When the battery pack to be long-term stored, charge the battery
pack to about 50% capacity, store in dry and ventilated place, charge
for every 3 months.
The battery pack and charger should be stored in clean, dry and
ventilated place, avoid contacting with corrosive materials and be
away from fire and heat.
The charging temperature range is 0-40℃. If the range is exceeded,
the battery performance will be reduced and the battery life will be
reduced.
(2) Transportation
The battery pack and charger should be packaged for transport,
prevent excessive vibration, shock or extrusion in transport process
and prevent the sun and rain.
(3) Maintenance
a) The battery pack should be stored in 40%〜60% charged capacity.
b) If battery pack is not used for a long period, it should be charging
completely and discharging completely one time for every three
month，then charge the battery pack to about 50% capacity, use the
specific charger.
c) In the maintenance process, please do not disassemble the battery
pack, otherwise battery performance will decline.
d) Forbid to remove any cell in the battery pack. Unauthorized
dissembling of batteries is prohibited, and may invalidate your
warranty.
e) Problem handling