External battery connector to UPS sparked small fire

[paulhung]

I just recently purchased an APC SmartUPS 2200RMXL3U along with the external battery pack (SU48R3XLBP). Right after unpacking and mounting in the rack, I connected the batteries in each, then proceeded to connect the external battery pack to the UPS. What happened next was shocking. Sparks and flames shot out from the rear connector, melting the connectors themselves.

I have heard of this happening before, but this is the first time it has happened to myself. I've always thought that the others may have done something wrong, but I did this install by the book and it happened anyway.

I have no tip to offer anyone to avoid this, other than test your UPS as soon as you receive it to avoid any hassling to obtain an RMA. Anyone else have a story like mine to tell?

 

[jaymaechtlen]

Was it connected backwards, or was the connection bad?
(or was it some other problem?)

 

[paulhung]

The connectors have housings shaped like an upper case "B" so that they can only fit one way.

I'm not sure what caused the problem, however normally when I have connected these batteries there would be a slight spark, not a massive one like this that melted the connectors.