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

[Greg Troxel]

Harlan Stenn via Nut-upsuser <nut-upsuser at alioth-lists.debian.net>
writes:

> I like batteries from RaionGroup.com or batterywholesale.com.
>
> There are some other companies out there that I will never buy from again.

I know people don't like to say negative things publically, but if you
could manage to say:

  I have in the past bought batteries from X, Y, and Z, raiongroup and
  batterywholesale.  My current practice is to order only from
  raiongroup and batterywholesale.

it would be somewhat helpful.  But I get it that you have tried a bunch
and have only 2 to say positive things about.

In particular, are you getting zeus from batterywholesale?  I am looking
at 12V 7Ah sized, and their 9 Ah, and it looks like zeus is the better
choice.

My own experience is that often batteries are not entirely right, both:
  - capacity somewhat below
  - a weak cell

I charge incoming batteries, and then do a controlled discharge at C/20h
(where C is nameplate capacity) using a West Mountain Radio (WMR)
CBA-II.  I then have a plot of V vs Ah.  Beware that WMR software is
seriously deficient because 1) it only runs on windows and 2) doesn't
run under wine.  So it requires keeping a spare computer with Windows to
use it.  I hear that newer versions have published protocols and perhaps
there is open source code to drive them.

  https://www.westmountainradio.com/cba.php

Often, I'll have a nice discharge curve, but say 6.5 Ah vs 7 Ah spec.  I
call that good -- that is a clue how bad things are.  And, my charging
could be a little under, so I don't get upset about this.

Sometimes, it looks good for a while and then sharply decreases around
e.g. 4 Ah.  This I interpret as 5 ok cells and 1 low-capacity/troubled
cell.  Such a battery is going to be trouble.

My two strategies are:

  - order 5 or 10 and sort.  put matched good batteries in UPS units.
    Use less good batteries in less demanding applications.* Last time I
    did this I got 5, and I think 4 were ok and 1 a bit low capacity but
    not broken.

  - order 10 from walmart.  test them.  return the bad ones to the
    store.   Last time I did this I think 8 were ok (> 6.3 Ah for 7!)
    and maybe 2 were either too low capacity or weak cell, and I just
    returned them.  I think I've also had ok batches.  I think the brand
    was UPG.

I note that while your tests are vastly better than almost everyone, you
haven't done controlled load testing so I think you don't really know if
your preferred vendors' batteries fare better than my UPG/walmart
experience.   However, last time I looked at walmart and thinking about
ordering, I was unhappy.

* I have about 200 Ah nominal of mostly-tired mostly-free-to-good-home
  batteries in parallel, solar charged, for ham use.  Some of them are
  wheelchair pulls, when the user perceived them to be diminished, and
  my testing shows about half nameplate capacity.  They are enormous,
  ~50 lbs for a 73 Ah, but multiple 35 Ah is still very useful in my
  application, vs someone who might be stranded if it failed.  Because
  they are in parallel any battery sees low current.  This strategy
  requires paying a fair bit of attention and I don't really recommend
  it!

> I try to get high-rate batteries, and they are harder to find.  As I
> recall, one should avoid "deep discharge" batteries for UPSes.  A deep
> discharge battery is great for constant load stuff (like wheelchairs,
> golf carts, etc) but UPSes need "shorter" bursts of lots of power.

There are two types of "sealed" batteries.   Both are properly called
"valve regulated lead acid" or VRLA.

  - Absorbed Glass Mat (AGM): electrolyte in fiberglass strands.
    rugged, high current.  Used for starting batteries in (larger) small
    engines and cars.   Most batteries are this type

  - GEL: electrolyte in a gel.  Cannot handle very high currents (C/1h
    bad, I think), either charging or discharging.  However, if you
    avoid that, cycle life more like 1000 than 500 for AGM.

The word "deep discharge" is usually used to contrast the above types
(as a group) with "starting" batteries.  Starting batteries, almost
always the "flooded" type (liquid electrolyte, some semi-sealed, some
where you can add water), are optimized for very high currents, but do
not do well if discharged more than a little.  Typical car batteries are
like this.

Anything not for starting a motor, where you intend to use the whole
capacity, should be AGM or GEL.   A UPS that is going to discharge in <=
1h -- which is pretty much all of them, should be AGM.

I would only consider GEL for a UPS if
  - the published and actual runtime is 4h or more
  - the manufacturer says GEL is ok (partially this is about charging)


re github wiki: how is planning for moving to a forge that doesn't use
open source code for AI training in violation of the license?  I am
growing increasingly cranky.