Getting battery runtime correct for a Symmetra LX with a SYAOPT4 cable

[chefash_apc]

Has anyone played with this cable and battery configuration?

APC sells it as "Accessory solutions to tailor the Symmetra to meet your specific needs"
http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=SYAOPT4

The manual shows it connecting to an "external Non APC" battery array"
To me this means I can connect a giant 120vdc battery array with some good HRL12500W batteries to my Symmetra 16k LX.
It seems like a great solution to avoid the low quality, short lifetime and overly expensive SYBT5 architecture.

My question, is without the battery communication cable and battery cabinet brain...
How will the Symmetra LX know it has the additional battery cabinet.
How will it figure runtime?

[BillP · Accepted solution]

there is an option via the installed network management card (and maybe the powerview..?) to add amp hours for external battery cabinets so that the UPS can factor in that "dumb" external cabinet and help provide a more accurate runtime estimate. i don't think that the UPS could every technically report more than 24 hours 0 minutes which may not even be realistic anyway.