[lug] UPS Recommendation
svqueen at gmail.com
Wed Aug 28 07:50:28 MDT 2013
A lot of times, if you buy a SLA battery from a retailer, they have sat on
the shelf for a long period of time, in a discharged state. This greatly
shortens the life of the battery. When purchasing a battery from a
retailer, try to judge how long it has been on the shelf. Sometimes
batteries have some sort of discernible date code on them. Try to check the
state of charge with a multimeter. A fully charged battery should be just
above 13V. (This is not entirely accurate, but what can you do in a store.)
If it is below 12V, try another battery, especially if you judge it to be
older than you would like.
I always put a date on a battery when I install it. I even do this with
primary cells, like in smoke detectors. Time passes for a battery pretty
quickly. You think its been 2 years, and it turns out to be 4.
On Tue, Aug 27, 2013 at 10:23 PM, Jed S. Baer <blug at jbaer.cotse.net> wrote:
> On Tue, 27 Aug 2013 20:57:44 -0600
> Sean Reifschneider wrote:
> > On 08/24/2013 07:57 AM, Jed S. Baer wrote:
> > > This particular UPS is several years old, and I replaced the battery
> > > just a couple years ago. I'm highly skeptical that the battery itself
> > > is bad.
> > "just a couple years ago"? What is the rated life of those batteries,
> > because a couple of years sounds about right to me. You can,
> > apparently, get 10-year rated batteries, but they are a lot more
> > expensive from what I've heard. A 2 to 3 years is about as much as I
> > get from APC batteries before the self-test starts showing them as bad.
> Well, it turns out the battery was bad. I was surprised by this, as the
> first battery (I think it was a Yuasa) certainly lasted a lot longer than
> that. I did try to find info on the rated life, but the web is flooded
> with sales info claiming "long life" etc., so the best I could find was a
> 3-year warranty, which is a good proxy for rated life, or that's my
> understanding from automotive batteries anyway. The replacement was, and
> is, a "Werker".
> This old UPS doesn't have any snazzy metering. I suppose I can set an
> alarm in my phone so I start looking for a better replacement in 2 years
> or so. With more time to shop, I should be able to find a Yuasa at a
> cycle or scooter shop.
> The landlord suggested I just get a SLA automotive battery. Wouldn't fit
> in the case, but wiring is easy.
> So anyway, rule #1: check your assumptions!
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