[ale] UPS

[Ron Frazier (ALE)]

Hi all,

I've been meaning to post a message about battery maintenance, and this seems as good a time and place as any.

You may or may not know that you cannot trust the charge meter in your PC to accurately read the state of the battery.  But, you can't.  However, the PC depends on being able to read this information in order to conduct a shutdown in the event of a power failure.  If the charge meter is wrong, the PC can end up losing power abruptly when the battery fails after being exhausted while the PC still thought it had charge.

To anyone reading this.  I need help setting the warning and shutdown power levels for a PC running Mint 13 with Mate.  I had this same problem with Ubuntu 11.04, and never did figure it out.  I'll elaborate more below.

Here's how you can test your battery's charge indicator.  This works with the live DVD for Mint 13 with Mate.  It should also work with Ubuntu 11.04, before they went to Unity.  In order to test the battery, you have to drain it completely, while watching the charge indicator.  Gnome provides a utility that can do this.  Even if the charge meter is wrong, draining and recharging the battery will sometimes fix it.

In general, you don't want to always be draining Lithium Ion and Lithium Polymer batteries to the bottom.  They don't like it, and lose a little bit of capacity each time.  However, if the charge meter is radically wrong, this causes other problems.  Doing a drain / recharge cycle a few times / year is probably a good idea.

Here's how to do it.

Don't try this in a VM.  Even if the VM thinks it has a battery, it probably won't react properly to a power failure.

Boot the Mint 13 with Mate or the Ubuntu 11.04 live CD or DVD.  The rest of the instructions assume you're using Mint.

For this to work, the PC must recognize your battery or UPS and be able to read the charge state.  If it can't fix that first.

Click the battery icon.

Click preferences.

Go through the menus and set the PC to never sleep on AC, never sleep on battery, never dim the screen, never blank the screen under normal conditions, and never spin down the hard drives.  Set it to only blank the screen if the laptop lid is closed rather than suspend or shut down.  Set it to shut down if the power button is pressed.  Set it to shut down if the critical battery limit is reached.  Save the settings.

Click the button for the main system menu.  Type screensaver in the search box.  Go to the screensaver settings and disable the screensaver.

Start the file manager and verify that none of the system's hard drives are mounted, which they shouldn't be unless you mounted them.

Now, unplug the power supply from the PC.  The battery icon should change to show that it's running on battery power.

Click the battery icon.

There should be a line that says something like laptop battery, or battery, or UPS, and then a percentage of charge.

Click that line.

This brings up a monitoring utility.

On the left side, click battery.  On the top tabs, click history.  Select graph type charge.  Select data length 2 hours.

You should now see a graph on the screen.  You can resize this window if desired.  This graph will only show data if the battery is discharging or charging.  Once it's full, the graph goes away.

You may now use the computer as desired while keeping one eye on this graph.  I've seen a few occasions where the graph doesn't seem to update.  This may be when minimized, but I'm not sure.  If you don't think it's updating, click the details tab then go back to the history tab.

Run the PC and watch the graph go down.  You want to keep running it until the PC shuts off.  Try to approximate a normal usage level.

If the battery is healthy, the machine should complain about a low battery around 20% and 10%.  Around 3%, mine complained about a critical battery and said it would shut down soon.  At around 1%, my machine shut down.

The battery was so low, I couldn't even start up the BIOS without plugging the system in.  I plugged it in, rebooted the live DVD, and am now watching the charging graph climb back up.

This drain / recharge process helps recalibrate the charge meter, which is in the battery, as far as I know.  It may eliminate inaccuracies in the meter.

The above is what happens with a good healthy battery.  With a not so healthy battery, or an older battery, you may see the charge graph abruptly drop from say 20% to 0% and then the computer shuts down.  I have one very old battery that actually shuts down at 50%.  If this happens, let the machine shut down.  Plug it in, reboot the live DVD, and charge it up.  Then, try the drain test again.

If the result improves, so the graph doesn't drop off a cliff, you can try the process a few more times, until you get a consistent drain cycle which drops from 100% to under 5% without anomalies.  In the case of the old battery I mentioned that drops off at 50%, it still does that, even after doing this process, but at least now I know it.

Now I can tell you why I need help.  I need to know how to change the percentages at which the Mint 13 fork of Gnome 2 warns me of low and critical battery and the percent at which it shuts down the system.  I don't want it waiting until 1% to shut down.  I want it to shut down at 10%, when there's still 15 minutes of battery life left.  As you can imagine, if the battery was not quite healthy, and it drops off a cliff and dies at, say, 8%, my PC would abruptly lose power.  If anyone knows how to change these settings, please let me know.

So, there it is.  That's how you can test your batteries and know how well they work and how much run time to expect and how well the charge meter works.  I think it's a good idea to do this to everything you have that has a battery, to cycle the batteries a few times per year, and to tweak your warning and shutdown settings to match what you can realistically expect from each battery.

Hope this helps.

Sincerely,

Ron



gcs8 <gcsviii at gmail.com> wrote:

>I have plan's to mod the APC UPS in my rack with 245ah
>batteries, instead of the ~10ah that is in the 3000va unit stock.
>
>
>On Mon, Feb 4, 2013 at 5:31 PM, Michael Nolan
><michaeldnolan at gmail.com>wrote:
>
>> In the past ~15 years, I've probably been through about 20 UPS units,
>and
>> had the best service out of APC. All of the 5 units I have now are
>APC.
>>
>> The last set of replacement batteries I bought were DOA, and I bought
>them
>> through the APC website, via a "recommended" partner. I could get APC
>to do
>> nothing about this and they offed me to the third party vendor who
>wanted
>> me to ship the batteries back at my expense and wait until they
>evaluated
>> them before replacement.
>>
>> These were APC labeled batteries and this apparently how they handle
>> replacements now.
>>
>> This would have left me with no backup on some critical and expensive
>> electronics. So I reconfigured using other units I already had.
>>
>> APC in the past has been very good, but I don't know what is going on
>with
>> their change in the way replacement batteries are handled.
>>
>> The batteries sit on the bench untouched since, and this thread may
>or may
>> not reawaken me to do something about it.
>>
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>> http://mail.ale.org/mailman/listinfo/ale
>> See JOBS, ANNOUNCE and SCHOOLS lists at
>> http://mail.ale.org/mailman/listinfo
>>
>>


--

Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9 Mail.
Please excuse my potential brevity.

(To whom it may concern.  My email address has changed.  Replying to former
messages prior to 03/31/12 with my personal address will go to the wrong
address.  Please send all personal correspondence to the new address.)

(PS - If you email me and don't get a quick response, you might want to
call on the phone.  I get about 300 emails per day from alternate energy
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Ron Frazier
770-205-9422 (O)   Leave a message.
linuxdude AT techstarship.com