APC Battery Time Remaining question

[BillP]

This question was originally posted by garu on APC forums on 2/2/2009

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Hi Guys:

I'm new and glad to see you here.

The remaining time in the pic bellow seems change all the time.
This UPS only supports one Cisco 4510 and some small device, while other UPSs which support 6510 or more devices show a stable remaining time chart.

All the enviroment looks the same, such as AC Cooling etc.

Do you know what's the reason? Thanks!

[blackAces_apc]

This was originally posted on APC forums on 2/24/2009

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Hi Guys

All APC UPS came with this? if on-line the runtime is estimated but if goes to battery mode is the accurate runtime, if ever i want the runtime about 30 min ( actual runtime ), any idea on how to get the actual runtime of the UPS, because most of the time i just check at the runtime chart. Yeah i notice that when the UPS is online the runtime is high but when the battery will kick the runtime will drop almost half from the on-line runtime.

[BillP]

This reply was originally posted by Angela on APC forums on 2/24/2009

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if you have never done a runtime calibration, it may be an idea to do so. you should be able to initiate this through the software. after a calibration, the runtime should be fairly accurate give or take a couple minutes - assuming the load doesnt fluctuate that much.

[blackAces_apc]

This was originally posted on APC forums on 2/24/2009

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As what you said the if the UPS is online the runtime is estimated but if the UPS on battery the runtime is accurate, so if i do the runtime calibration i can get the accurate runtime value even the UPS is online? basically what model came with this?

[BillP]

This reply was originally posted by Angela on APC forums on 2/24/2009

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this customer was using an SURT5000XLT/XLI unit. a runtime calibration SHOULD correct the issue but in theory the online versus on battery estimate should be fairly accurate. if its skewed, the calibration is one of the tools that can help adjust that. if it doesnt, depending on the model you have, there are a couple of other tricks to try and fix it.

[blackAces_apc]

This was originally posted on APC forums on 2/25/2009

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How about for the Back-UPS Series and SUA Series UPS..,? I try our SUA1500I and i found out that the Online runtime is higher than the on battery, i try to simulate power failure in order to see if the online runtime is a little bit close with the on battery runtime, but then i was shock when i saw the runtime on battery, the runtime was drop about 20 min. from the Online runtime.

[BillP]

This reply was originally posted by Angela on APC forums on 2/25/2009

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it is the same for all these smaller UPSs. it shouldnt drop 20 minutes - i would suspect no more than 10 at most.

after you let the UPS charge back up, was there still a huge difference?

[BillP]

This reply was originally posted by garu on APC forums on 2/26/2009

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Thanks,

If on-line the runtime is estimated, do you meet the similar situation? It seems the APC is estimating the remain running time all the time, 🙂 I wonder what was going on that time.

[blackAces_apc]

This was originally posted on APC forums on 2/26/2009

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after the ups was charge, its back from the original online runtime, i suspect, maybe the battery is weak already or need to replace..do you think its a battery problem?

[BillP]

This reply was originally posted by Angela on APC forums on 2/26/2009

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how old is the battery? if its brand new there are a couple of items we can check. it seems to be a problem with the UPS calculating it incorrectly to be honest with you. there isnt much we can do if the battery isnt new.

let me know

[blackAces_apc]

This was originally posted on APC forums on 2/26/2009

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its not a brand new unit, we they replace the battery already almost 2 yrs from the date we change. so if we change a new battery, i can expect that i can get the accurate runtime?

[BillP]

This reply was originally posted by Angela on APC forums on 2/26/2009

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you should get accurate runtime and then i can give you a couple things to do to get the UPS to report the accurate runtime through the interface as well.

the only trick to doing it with older batteries is a complete discharge and recharge which you have already done.

[BillP]

This reply was originally posted by Angela on APC forums on 2/3/2009

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hi,

may i ask what UPS this is? generally, on the smaller UPSs, the runtime remaining when the UPS is online is an estimate. when the UPS goes to battery its actually updated and is a lot more accurate based on the load. is the UPS going to battery a lot where maybe it is calculating the runtime better so the value is changing?

but yeah, if you have a static load, it shouldnt fluctuate THAT much.

[BillP · Accepted solution]

This reply was originally posted by garu on APC forums on 2/4/2009

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Thanks man,

The model is RT 5000, the load is only around 15%...
At first, I thought maybe it's caused by the self test, but no, self test schedule is every 14 days, so that isn't the reason.

Also I check the log, and didn't find the UPS change to battery mode a lot...

Weird...

Message was edited by: garu