SC said:
VanguardLH wrote ...
*** That depends on the set up. In my experience, most of the APC's
that use 2 batteries have them in series, which is not going to
increase the amperage, but is going to make it like a single 12v
battery of the same amperage as the 2 6v batteries. If the batteries
are in parallel, then the amperage would be increased and the
charging voltage would still be 6v.
I saw in Jo-Anne's reply that she said they were 6V batteries (instead
of 12V batteries). So, yes, they are probably in serial to get 12V
which then gets stepped up.
Tis too bad they went with two 6V batteries. The packaging results in a
fixed minimal cost for each battery and why Jo-Anne had to spend $50 on
2 batteries (to get 12V) rather than $32 for 1 battery (at 12V already).
I'm not sure which UPS she got. From the image and dimensions listed at
http://www.pricedbelowmarket.com/assets/img/253912_4_600w.jpg, it seems
they had room to put in taller 12V batteries. One place listed the
battery pair (
http://excessups.com/backups-bk600-p-17.html) for $35 but
then add in their $9 shipping cost for a total of $44. BatteriesPlus
isn't the cheapest place to get batteries but they have most any that
you need, they're convenient, if there's a problem then there's a store
to take them back, you're paying for their expertise, and you get a
guarantee (might only be a year), plus you're not paying extra for the
shipping of the batteries (well, that cost is probably already rolled in
to the retail price), and you get the battery now instead of maybe 10
days later and without worrying about damage during shipping.
*** $250 seems awfully steep to me for a 600VA UPS. Even Staple's (as
high
priced as they usually are) has a 1kVA APC for about half that:
http://www.staples.com/APC-Back-UPS...g-UPS/product_803761?cmArea=FEATURED:SC3:CG75
I didn't check and thought that is what she said she paid. I looked
this time and don't see her say that. Yes, that would be a steep price
NOW but I don't have an ancient retail price list to see what she
would've paid 13 years ago. Remember that UPS'es have dropped in price
just as has memory, drives, and other computer components. When my
father bought the 2kVA UPS (with a huge 50-lb isolation transformer for
true sinusoidal output) UPS back way over a decade ago, it's cost was
close to the same as its VA rating. That's not true today; however, the
VA rating is only one measure of a UPS and other features can quickly
add cost to a UPS. In fact, I've read where the "active" power supplies
might not work with the typical UPS (that has stepped sinusoidal output)
so you have to not get one of those active PSUs if you get a cheap UPS.
I didn't bother to lookup what her UPS would cost (now). Cost analysis
is always a requirement to figure out if you repair a device or replace
it. $50 is still cheaper than $80. I don't think her old APC
Backup-UPS 600 gave her any more features or protection than would one
of the Cyber Power brick UPS'es of today at $74 (Newegg's price). If it
had been one battery at $32 then it was a good deal to replace the
battery since that would be 43% the cost of getting a new UPS. At $50,
the new batteries are 68% the price of a replacement UPS. I usually
consider not repairing a device when its repair cost exceeds two-thirds
the cost of a replacement (and often start pondering a replacement
versus repair at just 50% repair cost).
For some folks, saving $24 is still something they want to do. After
all, coupons would be worthless product lures if consumers didn't want
and use them.
*** You may or may not get more run time out of the 9Ah than the 7Ah.
It depends on the charging circuit in the UPS. If it's output is only
rated for 7Ah batteries (or maybe 7.5Ah for design and wear
purposes), then that's all the 9Ah battery is going to be charged to.
Odds are, like in my previous statement, those two batteries together
are still 12Ah since they are in series. If the charger isn't
designed for a larger battery, it can't charge it to its full
potential.
Huh? Since when would a charger circuit know or care about the
*capacity* of a battery? It's concerned with voltage and its charge
rate. It's not like the charger would only charge for a specified
period of time based on the charging rate for some unknown but limited
capacity. An older battery will take longer to charge. In fact, one of
the measures by which you can determine if your battery is becoming
weak[er] is how long it takes to charge. An older or weak battery would
take longer to charge. If the charger shutoff after some fixed time
interval then the battery may never get fully charged and eventually
never will get fully charged. A 9AH battery would simply look like the
7AH battery that isn't yet fully charged and still need more charge.
So, yeah, it will take longer to charge just like it will take longer to
discharge.