Replacing an APC UPS XS 1500 Tower?

[Anonymous user]

Hi, It's been some 5-6 years since I purchased this unit. This APC unit has worked well for me and it hasn't had to work very hard in that I have a home backup generator. As such when power is lost it's only a matter of a few seconds before the generator kicks in and it gets up to speed. My questions regarding the APC UPS XS 1500 Tower:

If I was to replace it what would be a comparable model today?
If the needs are not much more than stated above should I replace it or just get new batteries and forget it?
If I'm over simplifying; what are today’s considerations?
Should I just let it go until it just dies then consider a new one?

I realize there is no one answer but I'm happy to research if pointed in the right direction.
Oh and the reason I'm looking is the past few months the unit has kind of booted beeped a few times, without a visable power outage, and on this last outage it cycled between green light, yellow light and reboot/off. Kind of caused my PC to start to boot and then get dumped cycling on and off and it did this for about 30 min before I caught it. I just shut it off until the power came back on. FYI, I've not ever seen the replace battery light come on but it must be about due.

Thanks, Greg