UPS maintenance question

By Tedster
May 25, 2005
Topic Status:
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  1. I have an APC BackUPS Pro 500. Is it required to deep-cycle the battery once a month or sooner? I bought it used, so I have no documentation. I just popped a new battery in it and charged it once, then drained it once.

    What is proper maintenance on UPS batteries? I want to maximize life.
  2. Rick

    Rick TechSpot Staff Posts: 6,304   +52 Staff Member

    The UPS batteries I am familiar with are lead-acid, like a car battery. Unlike with other rechargable batteries technologies like NiCd, NmH and Lithium, "deep charging" isn't necessary for this type of battery.

    Just give the battery plenty of consistent use and expect it to last for a few years. Of course, there's things that can go wrong with a lead-acid battery, but that's not really anything under your control. Just depends on the design of the UPS itself.
  3. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    Wasn't sure. I've heard both suggestions.... to deep drain and recharge, and also not to - keeping 'em charged.

    I know it's not good to not have them charged if you're storing them, but I want to know about regular use. :confused:
  4. tdeg

    tdeg Newcomer, in training Posts: 348

    I know car batteries don't like to be drained entirely, so I'm going to assume that you shouldn't do that with your UPS.
  5. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    Well I have deep drained it only once. I don't think I will do that anymore.
  6. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    So only partially drain them every once in a while?
  7. patio

    patio TechSpot Maniac Posts: 700

    A buddy of mine from another Forum replaced his UPS battery with a motorcyle battery 2 years ago and has had nary a problem...
    i'll ask him about cycling and if he does it.

    patio. :cool:
  8. RealBlackStuff

    RealBlackStuff Newcomer, in training Posts: 8,165

    I have an APC Back-UPS 500.
    It is now nearly 5 years old, and works like a charm.
    Attached are 2 PCs, 1 monitor, 1 printer, and the mouse/network/KVM AC-DC adapters.
    Lots of construction in my area, and power goes out regularly because som eejit cuts a cable with his JCB.
    The UPS has never failed yet! And I have never done any maintenance.
  9. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    The old battery I pulled is about the size of a motorcycle battery. I'm sure a motorcycle battery would work. I don't know what the voltage is on motorcycle batteries.

    I'm just trying to maximize the life of the battery. I have had people tell me that deep-draining is not good and others tell me that you should once in a while.
  10. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    So you have never purposely drained it?
  11. RealBlackStuff

    RealBlackStuff Newcomer, in training Posts: 8,165

    I don't even know what you are talking about (drained...), do you?
  12. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    drained = discharged all the way
  13. RealBlackStuff

    RealBlackStuff Newcomer, in training Posts: 8,165

    I see no reason whatsoever to do that. My UPS is working perfectly, as I said before.
    You paranoid about batteries, or what?
     
  14. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    not paranoid, but ups batteries aren't cheap - about $30 a pop

    The more I have been reading, the more I'm seeing that they should always have a charge on them. Deep cycling in not recommended.
  15. RealBlackStuff

    RealBlackStuff Newcomer, in training Posts: 8,165

    If it's any help, I power down everything "computer" overnight, with a masterswitch, meaning that the UPS also is not connected to the mains.
    As I said, never a problem.
  16. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    From what I've read, it's good to always keep a charge on them. So I'm going to try it and see what happens over the long term.
  17. patio

    patio TechSpot Maniac Posts: 700

    My buddy says he has never dis-charged the battery fully and it's still ticking along...
    BTW motorcycle batteries come in both 6 and 12 volt models...
    He used one because it was cheaper as a replacement than the UPS battery.

    patio. :cool:
  18. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    I've heard you can do that. I suppose any battery with the same voltage and amperage output would work - provided it was rechargable.

    From my understanding deep-cycling would stop "memory developmemt", however it also creates sulphur crystals which shortens battery life.
  19. SNGX1275

    SNGX1275 TS Forces Special Posts: 12,280   +223

    You don't want to do deep cycling (full discharge then full recharge) on lead acid batteries. Now that may not be true for all lead acid ones the gel ones might be able to take it. But its definately not good on your common car battery, or motorcycle battery.

    As for memory effect. Thats largely regarded as a myth, and only in any truth in NiCads from what I've read. It is true that you can develop a memory in NiCads, but only highly regulated conditions, not normal conditions. So supposedly to remove that memory you would need to fully discharge and fully recharge a NiCad. Problem is that not all cells in a multicelled battery (battery packs for example) discharge identical to each other, one will be out before the others, and then it ends up being charged a little by the others, its not a very acceptable way to it. If you had to you should do each cell individually and to the exact same voltage.

    I did try to do a little research on various types of batteries and what acceptable and unacceptable care for them is, and didn't find any 1 good source for that. Plus a lot of sites tend to disagree with each other. I was suprised to not find any scientific papers on this area, I'm sure they exist, I just didn't get any with limited googling.
  20. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    yeah, I googled quiite a bit on this topic. We have motorola radio batteries at work that develop a memory after a while, but I think they're ni-cads. I wasn't sure about lead-sulphate. I do know from my readings that lead sulfates have to be kept wet (particularly car batteries.) The ones inside UPS are usually sealed and a gel type and therefore no maintenance is required other than keeping them fully charged.

    I agree that there is not a whole lot of information readily available on the net - however I haven't really done scholarly research (like a library visit.)
  21. dtkenmo

    dtkenmo Newcomer, in training

    Look here: Battery Book

    The author has very generously made the entire text of his book available online. Table of contents in menu on the left links to corresponding chapters, or you can read from end to end... :)

    Also check out the sister site: Battery University

    So now everyone can stop swapping misinformation & hearsay and get educated on the subject ;) :D
  22. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    Very informative. I guess lead-acid UPS batteries should always have a full charge on them if possible according to the article. Capacity will decrease slowly over time, but this is unavoidable.
  23. SNGX1275

    SNGX1275 TS Forces Special Posts: 12,280   +223

    Thanks dtkenmo, I just now started to look at it, so I haven't read enough for an opinion, but hopefully its good information and I can learn something.

    I used NiCads in RC Cars for years back in the early to late 90s, but haven't hardly touched 7.2V Packs since (and their quick chargers (15 minute)). I have dealt with the AAs and such for cameras and gps, but with both NiMH and NiCad, but the chargers for them are so much slower. I'm guessing with RC you want fast recharge at expense of battery overall life, but not sure. I'm more intersted in the 'wet cells' and types, and how they deal with charge/discharges. Hopefully that link will help.
  24. Bobcat1132

    Bobcat1132 Newcomer, in training Posts: 94

    my father in law uses a ups in the isp not sure on how big but its huge about 5 and a half feet tall and large enough to run a computer farm and it is NEVER discharged so...
  25. Tedster

    Tedster Techspot old timer..... Topic Starter Posts: 10,067   +13

    So far, the research indicates that lead-acid should not be deeply discharged and should also have a charge on it as often as possible.
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