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To tell your Cyrusher XF690/ XF770/XF590 battery whether works properly, you need to use a voltmeter to help to test input and output voltage.
If both voltages are the same but higher than 42V, which means the battery is fine;
If there is some difference between input and output which means there may be an issue with the battery input or output connection or even the battery cell, in this case, please contact us support team directly with your test image or video by visiting the following link: