APC UPS question

[Salamander 2]

I just bought an APC UPS (Uninteruptible Power Supply) - the Back-UPS XS-900). I got the battery out on the compartment and then connected the one wire that came unhooked - per the directions. When I first started to connect it, it gave off a small electrical spark. Then I connected it without any further discharges. Is this anything I need to worry about?

Also, the directions say to charge it 18 hours prior to use. Does it really take that long?

[nn_step]

always be concerned but not really a need to worry.
follow the directions

[Salamander 2]

Thanks!