Tuesday, December 18, 2018

UPS Battery Replacement

Commentary: My old UPS battery died.  Rather than buying a new unit, I replaced the battery. A UPS is recommended if you have dirty power -- and my power was dirty because of a power-hungry laser printer that keeps rebooting the PC each time it prints.  Related article:  PC Reboots after printing.

Somewhat humorous update: This article was written in 2010/2012 -- the last time I replaced the battery.  It failed again today, 6 years later.  Time to get a new battery. 

An un-interruptable power supply (UPS) provides power when the main grid fails. During a "power anomaly," these relatively inexpensive devices keep the computer running for about 10 to 12 minutes -- giving enough time to save your work and shut down. If you are not at home, included software can gracefully shut the machine down.

But the real reason for a UPS is to protect the hard disk and motherboard from brownouts and power surges. Power gremlins like these can fry the equipment or corrupt the hard disk -- which would ruin everything. Remember my mantra:  Data is more valuable than hardware.

Related Keyliner Article: UPS turns off and on

My UPS Pooped-out and the PC Reboots:

My then six year-old UPS [now approaching 15 years] APC cs350 has been dying. When it was new, it ran the computer and two monitors for about 10 to 12 minutes -- now it can hold a charge for 2 seconds.

The unit has a sealed, lead-acid rechargeable battery and like a car battery, it can lose its spunk. 

The final straw came last week when my Brother HL-2040 laser printer (Keyliner reviewed here), printed a page and then surprised me by rebooting the workstation. When it crashed, the document was lost and the RAID disk array failed.  See also, this newer keyliner article:  PC Reboots after Printing.

As I noticed later, it was crashing each time someone else printed from their laptops or tablets -- but they never noticed my computer would power-down.  The prior week I noted the RAID was perpetually rebuilding (article: Raid Power Gremlins).  When I put two-and-two together, I understood this was a power issue. 

Laser printers pull an amazing 450 watts and something like 15amps.  Lights throughout the house, and probably throughout the southern part of the State, dim whenever the printer cycles.  The power company rejoices when I print. 

I have always known the UPS was compensating. Each time the printer fired-off a page, the circuit would brown-out and the UPS stepped in to save the day -- that is, until it became too tired.

APC cs350:

I am partial to the APC brand cs350 UPS, which costs about $70 (now $90 and is amazingly still produced).  You can get one at any office-supply store. It features a user-replaceable battery and mine is now it is on its fourth battery and it will fail again in 2025.

Installing a new UPS is a cinch: Plug it into the wall. Plug in the computer and monitor, and you are set. I should, but don't bother with the USB connector, which can tell the computer to shut down when I am away.  I use the UPS to protect me from those one or two-second power blips you see every now-and-then.

Most UPS's, including this one, have two rows of power plugs.  One side is [battery and surge-protected] and the other is [surge-protected with no battery]. Here is the back-side view of the cs350:

Although it is safe to plug an inkjet printer into a UPS (on the surge-side), never plug a laser into the UPS because it would suck even a large UPS to its death. But out of necessity, the printer and computer live on the same household circuit -- which is the same as being plugged into the same power-strip.

User Replaceable Batteries

At first, I was going to buy a new, smaller UPS, figuring it was cheaper than a new battery. That would be a mistake.  Buy this model of UPS and replace the battery for the rest of your life. 

Replacement batteries can be found at these easy locations:

BatteriesPlus $40.00 
Staples for $35 -special order  "RBC2"
Lowes Home Improvement $35, in the lighting section of all places

To replace the battery on this model, turn the UPS on its side, and pull the battery out, unplugging a red and black cable. It takes about a minute to replace.  The battery is surprisingly dense, weighing about 5 pounds.  Old batteries must be disposed of properly at any auto-parts, tire-and-battery shop, or battery store.

I have a second UPS plugged into the house wiring closet, where the routers, wireless, and SAN drives are connected.  This keeps these devices from resetting when the power goes out.  If you hate re-programming fried equipment, protect them with a UPS.

Your comments are welcome.

Related links and products:
Staples: New cs350
Raid Volume Rebuild
Raid Power Gremlins

UPS turns off and on
PC Reboots after printing

Replacement Battery: 12V 28W 7.2AH
GP 1272 F2  (APC)  RBC2
GP1272 F2 1272A
Werker 12Volt 7Ah AGM Battery .250 Terminal WKA12-7F2

Battery size:  15cm (16") long, 6cm (2.5") wide, - about the length and width of a cell phone, by 9cm (3.5") tall.   This is a very standard size, used in this UPS, and in all kinds of battery-powered lighting fixtures.
05201050BAT, 182735, 23275, 6DW9, 6FM6, 6FM6A, 6FM7, 791181624, B00007, BAT0062, BAT0370, BD712, BERBC31, BP127F, BT712, CB1270, CFM12V65, CP1270 , CS36D12V, DG127F, EP1229W, EP1234W, EVA12-7.5F2 , F6C127BAT, GNBSP12V7F1, GP1270, GP1270F2, GP1272, GP1272F2, GT12080HG, HE12V77, HEPNP712, HEPNP712FR, HP712, HR1234WF2, HR1234WFR, HR912, LC-R127CH1, LC-R127R2CH1, LCP127R2P, LCR127R2P, LCR129CH1, LCR12V65BP1, LCR12V65P, LCR12V65P1, LCRB126R5P, MBCFM12V72, NPW3612, NPW4512V, PE12V72F1, POWPS1270F, POWPS1270F2

The vendor rates the battery for 5 years.


  1. Good article. I, too, have had a positive experience with BatteriesPlus. Purchased a cell phone battery. Will use them again.

    An interesting aside - there are true UPS's and battery backups. What's the difference? A true UPS runs on the battery continuously and the AC current keeps the battery charged. This also provides line conditioning. The Battery Backup runs on the AC power & when it fails, there is a split second when it switches from the AC to the battery. While technically this is not a UPS, most home users would be well served by such a device & with the cost savings in their pocket.

  2. I was not aware of the difference. Is it safe to assume that APC cs350 is a UPS?

  3. I didn't know for certain. I went to the APC web site & looked up the CS line. It states
    "APC CS - Best value battery backup & protection for business computers."
    As I remember (it has been a while) most of the true UPS devices started in the $200-$300 range and went up quickly from there.
    This is my OPINON but the odds of a PC writing at that exact second the switch over takes place is far less than a server. Also the value of the data on a server is far greater than that on a PC.

  4. The issue may be moot for a single computer. Whether the power always runs through the battery or if it switches over in a milli-second is probably inconsequential -- as long as the results are the same.

    Thanks for your comments.


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