Got mine today. The charging of it may be simple but here goes. First of all I read somewhere that the connection on the battery is always loose it's a common fault and sure enough it was very loose. Tightend it up and pluged the charger in the backpack. Light came up red. Pluged it into the msins and it came up green and made humming noise as if charging. Should the light be green and also should my voltage metre be moving. This is it's first charge. Just need to know if all this is correct. Thanks guys.