Titan 3K Onliine UPS Randomly "Self Testing"

Hi all :-)

Have enjoyed helping many ppl on tech forums for years, but now it's time to ask you wonderful people for some help . . .

I have a Titan 3K online UPS that is randomly going into 'Self Test' and beeping for no reason that I can find.

It has been working wonderfully without fault for over two years, and I have just recently replaced all of it's 8x 12v 7.2 AH battery's with brand new 12v 9 AH battery's.

This battery replacement was due to the unit beeping every now and again and once turned off and shutdown I'd found three(3) of the battery's had not been holding charge and were between 10.5v to 11.5v. So I replaced them all, and restarted the UPS.

Now every now and again it just randomly beeps and enters a "Self Test" showing the usual LED lights for self test, and recording all self tests into it's log file. It has no set...