Do any UPS's run with dead batteries?

[Anonymous user]

Hello,
I've got a couple of questions regarding my Smart-UPS 700 and other APC UPS's.

#1. I've got a server that has been randomly rebooting (once every 5-8 days) for the past few months. I've eliminated RAM, power supply, and software as possible causes. Recently my batteries in my Smart-UPS 700 died. Is it possible that the cause of the reboots was the dying batteries?

#2. I always assumed that if the batteries on my UPS died, the UPS would continue to provide power and surge protection to the connected server. The UPS would just be unable to provide any battery backup in case of power failure. I have learned this is NOT the case and the unit will do very little (or nothing) without charged batteries. So, the question, is there a suitable single server UPS that DOES continue to provide power, even though the batteries are dead?

Obviously I need to evaluate my current method of testing my UPS, but I'd much prefer the unit could just alert me of failed batteries and continue to operate with dead batteries until they are replaced at a time convenient for me (aka: not at 5am Monday morning)

Thanks for any advice,
Aaron

[Erasmus_apc · Accepted solution]

toadly wrote:
#1. I've got a server that has been randomly rebooting (once every 5-8 days) for the past few months. I've eliminated RAM, power supply, and software as possible causes. Recently my batteries in my Smart-UPS 700 died. Is it possible that the cause of the reboots was the dying batteries?

Yes it is possible that the bad battery in your UPS was causing the reboots. If the UPS ever had to go to battery, this would have of course caused the UPS to "drop" or reboot the load. If you were using any software with the UPS this could also have contributed to the UPS rebooting the load.

#2. I always assumed that if the batteries on my UPS died, the UPS would continue to provide power and surge protection to the connected server. The UPS would just be unable to provide any battery backup in case of power failure. I have learned this is NOT the case and the unit will do very little (or nothing) without charged batteries. So, the question, is there a suitable single server UPS that DOES continue to provide power, even though the batteries are dead?

While not designed to run for long periods of the with a "dead" battery, our SUA line of Smart-UPS units will provide power to the load if the battery is disconnected during operation and/or if the battery is in "need of replacement" per the "Replace Battery" LED on the front of the system. This LED should come on a few weeks prior to the unit's battery actually failing completely. The units will also come "on" and provide power to the load if the battery is disconnected. I have an SUA1500 at my desk which is powering my computer, phone, monitor, and a small hub here at my desk...and currently the battery is sitting on my lap disconnected. It's going to beep and be very annoying but the SUA units do behave better with a bad/disconnected battery than the older SU Smart-UPS do.

[Anonymous user]

Thanks Erasmus. Very helpful.

I think I'm going to replace the Smart-UPS 700 (PN: SU700BX120).

The only piece of equipment this UPS is meant to protect is a file/print server with a 340watt powersupply (no monitor or additional equipment). I was thinking I would replace the unit with PN: SUA750.

The SUA750 provides 500watts for 4.6 minutes. Really I just need time for a graceful shutdown if needed. What would the formula be to figure out how long the SUA750 would power my 340watt server?

[Erasmus_apc]

340 watts running on an SUA750 would allow for about 10 minutes of runtime. I cannot provide the actual algorithm we use to calculate runtime, but you can go to our website and get the product page for any of our UPS systems, and go to the "Compare Models" tab to see a small calculator where you can put in any wattage amount you want a runtime estimation for.

This link should take you to the Compare tab for the SUA750:

http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SUA750&tab=compare

[Anonymous user]

I've decided to go with the SUA1500 to get a much longer run time as well as have some overhead for future devices. Your input was very helpful. Thanks again.

Aaron

[Anonymous user · Accepted solution]

Similar question:

I've got a Smart-UPS 1000, had been running with a bad battery for a while. I've put it on the bench and removed the battery, and it won't power on now.

I've got a replacement battery coming but now i'm worried it's not working normally. Should I be able to plug it in with no battery and have it power on normally?

Thanks!

Stew

[BillP]

Hello,

One thing to note with one of our units (Smart UPS) with a bad/discharged, or no battery is that when it turns off, and has no incoming power after a period of time the internal voltage of the unit will discharge. When this happens the unit is no longer be able to sample the internal voltage to actually turn on.

So, if you have a unit without a batt, or a totally discharged bad battery, and it has been off for more then 10-15 minutes without power, it will not start again until a good battery has been placed inside it.

You can test this on any working unit (Smart UPS), a quick way to do so would be to unplug the unit, turn it off, unhook the battery and hold the OFF button (the one with a circle on it) until it makes a beep/click noise, plug it in, and try to turn it on. Then connect the battery back up, and it will turn on as normal.

If the unit has no battery, and does NOT lose power for more than a few minutes, it will indeed turn on.

This is not abnormal.

Message was edited by: syn2083

[Anonymous user]

Whew! I will just sit tight until the replacement battery arives then. This unit was actually replaced with a larger one and this unit will be re-purposed when the battery arrives, so I should be good.

Thanks for the quick replies!

Stew

Message was edited by: Stew-2