You've got to clarify what you have, what you're looking for (what's a kite mark?), and answer richard1st's questions. You should identify what company custom made these UPS systems for you (and maybe give some idea why you had UPS systems custom made to begin with).
Even then, if there's no markings whatsoever on the UPS systems, there's not much we'll be able to tell you here.
Have you tried calling your custom manufacturer?