[Nut-upsuser] Eaton 5PX 3rd party batteries

[Dan Langille]

On Wed, Nov 27, 2024, at 10:56 AM, Greg Troxel via Nut-upsuser wrote:
> Dan Langille via Nut-upsuser <nut-upsuser at alioth-lists.debian.net>
> writes:
>
>>> On the website, they say 5.73 pounds (5 lbs 11.6 oz).
>>>
>>> Two of the batteries were 5 lbs 11 oz.  The rest were all 10, 9, or 8 oz.
>>>
>>> See my bar chart at https://bsd.network/web/@dvl/113555334752647203
>>
>> The batteries are all within 3% of the expected weight. Seems good enough for me.
>>
>> I gave some thought as to how to distribute those 16x batteries within the UPS (4x) and the external battery unit (12x).
>>
>> In the following, I'm omitting the 5lb part of the weight and mention only the ounces.
>>
>> Not that I think it will make much difference, but I'll put all the four equal batteries into the UPS (4x 10oz batteries).
>>
>> That will leave the following for the external pack:
>> '
>> * 2 x 11
>> * 1 x 10
>> * 7 x 9 
>> * 2 x 8
>>
>> The other choice I'd make: put 2 x 11 and 2 x 10 in the UPS, leaving the external battery
>> unit with:
>>
>> * 3 x 10
>> * 7 x 9 
>> * 2 x 8
>>
>> I don't know enough to know if this matters and I expect I'm merely overthinking this.
>
> You are definitely overthinking it :-)  Perhaps you've previously been
> diagnosed as a nerd!

Possibly. I also have a rain-barrel project underway, and I know I'm overthinking that one too.

> But, I would either put the 4 strongest in the UPS, or the 4 weakest,
> making the external pack better, since it is more important.
>
> I would suggest that you get a West Mountain CBA, if you want to
> continue to overthink this.  We are assuming that more lead is more
> capacity, but there are also weak cells, not clearly related to missing
> lead.   What really matters, IMHO, is how many Ah one can pull out of
> the battery, and measuring that directly seems more direct.

I understand, and no, I'm done with this stage of the process. I don't want
to geek out any further.

So far, every battery has been charged. Each took about 30 minutes. When charged
they measured about 13.3-13.5V.  The first batteries I charged are now at about
12.9-13.1V - one was 12.8V

They're sitting in a room that is about 63F.

My next step is to pull the main battery from the 5PX and replace those units. However,
it's 3:30 PM and I'd rather start such a project earlier in the day should
thing take longer than expected. 

One server has a drive ready to be replaced and two drives are to be
relocated from the drive bays at the front to PCI slots in the rear of the server.
That process is waiting on parts. I was going to wait for those parts and do the drives
and batteries at the same time. I changed my mind; I'm not going to wait. Plus,
the batteries may be a big enough job by themselves. I am sure the Eaton 5PX legacy
is not a hot-swappable unit. I'll power everything down.

> Thanks for posting about your journey; it has been illuminating to me.

I'm glad it helps. I write mostly for selfish reasons and encourage others to do so
too. It helps to know what you did should something go wrong and/or you want
to repeat the procedure later. If you make your writing public it will also
help others and I'm thankful of that.

-- 
  Dan Langille
  dan at langille.org