Hi, I have a five year old UPS (500VA, local made). It's battery is not working now. UPS turns off in 5-10 seconds when the power goes off. How much will a panasonic lead battery cost for this. Is it good to replace battery or should I buy a new one. If you suggest a new, let me know if there is any UPS that I can connect serial port on my PC to monitor battery status and put auto shutdown in case the battery power is low (just like a notebook). I am looking for a 600VA (not more than that). Brand not a problem as my old buddy didn't fail for 5 long years.