seeSURTD6000RMXLP3U EPO draining battery?

[tpangburn]

We had a case on a test rack where we disconnected the power and had the EPO button on and the battery died over the weekend. Does the EPO button being set drain the battery when the unit is powered off? Its possible maybe the battery was going bad but I just wanted to see if the EPO would have anything to do with it?

Also how long can you leave the UPS unplugged assuming a fully charged battery can you leave the UPS off and un-powered?

[Teken]

The EPO can be wired in two ways Normally Open (N.O.) or Normally Closed (N.C.). The preferred way is N.O. wiring configuration as N.C uses the UPS internal 24 VDC power circuit all the time. You can confirm which EPO wiring method is being used by looking at the (green, blue, grey) phoenix connector on the rear of the UPS EPO port.

If there is a jumper wire inserted in the screw ports it’s wired as N.C. You’ll want to validate the same on the EPO Switch in case they placed the jumper in there instead which isn’t very common but validate to be sure! ☝️

All battery cells lose power (self discharge) when at rest and depends on the chemistry, technology, temperature, age, and usage. You can look up the battery specifications and see what percentage of charge is lost simply by sitting idle. Keeping in mind those values and specs are based on a brand new cell.

You can get a rough idea of the battery cells in the UPS by completing a self test. If it fails immediately after being fully charged they need to be replaced. A more accurate method is to measure the internal resistance of the individual cells with a conductance tester. Measuring surface (voltage) charge is not accurate. 

A true test is loading the battery with a defined current draw and see if it reflects the specifications from the battery maker. Combined with measuring the internal resistance of the cell you can than know how good, bad, the cell is.

All we want to see is reasonable operation runtime based on a defined connected load. If it was 30 minutes when new and now it’s 1 minute it’s easy to decide. If the the runtime is 25 minutes that’s up to the company to decide balancing cost, uptime, reliability, and risk!

Regardless, batteries are consumable’s and should be budgeted for replacement like any other maintenance item in the business. The industry average is 3-5 years of service based on ideal conditions. 

[tpangburn]

So, I did find this answer in the FAQ (below) for that said your unplugging the UPS for over 24 hours you should unplug the batteries. That being said are the batteries disconnected when they are shipped to us when we buy them? I haven't gotten an answer from my end yet, so I am curious.

With SmartUPS RT (1kva to 10kva):

Any time a SmartUPS RT (1kva to 10kva) will be turned off without input power present, or allowed to operate in bypass for over 24 hours, the battery modules should be disconnected to prevent unnecessary discharge. Depending on the health of the batteries, they can discharge below start-up voltage (approximately 85vDC) within 72 hours if the UPS is not operating normally.

[Teken]

All units ship with the battery disconnected from the main system. Often times the ends of the connector is covered in a bright yellow caution tape.