PowerWalker VFI 1000 TG Mode D'emploi page 34

9. Maintenance
9.1 Operation
The UPS system contains no user-serviceable parts.
9.2 Storage
If the batteries are stored in temperate climatic zones, it is
recommended to recharge those batteries every three months for 1~2
hours. It is highly suggested to shorten the recharging intervals in every
two months at locations where subjects to high temperatures.
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