Frequently Asked Question
Please remember that the life of the battery starts at the time of production (not at the time of first usage). This time might be considerably long (even a full year in some cases). A battery must be recharged every 2-3 months in storage, otherwise it depletes its capacity.
How to read voltage level: https://support.powerwalker.com/kb/faq.php?id=68
How to choose the right batteries for replacement: https://support.powerwalker.com/kb/faq.php?id=76