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

[Greg Troxel]

Dan Langille via Nut-upsuser <nut-upsuser at alioth-lists.debian.net>
writes:

not Harlann, but my $0.02

> On Tue, Nov 12, 2024, at 11:49 PM, Harlan Stenn wrote:
>
>> - put each battery on a charger for several hours
>
> Do you have a recommendation for a battery charger? Or a list of features to look for?

  - temperature compensation (float voltage varies with temperature)
  - desulphation, for dealing with troubled batteries
  - perhaps, higher voltage until current drops

I have this

  https://optimate1.com/product/om3/

which I don't claim is the best, but it has been reasonable.
 
> The purpose of waiting for a day is for stabilization? Waiting for one
> of them to die? Achieve a solid charge?

Lead acid batteries charge rapidlly when presented with 13.5V and the
batteries are discharged.  The rate of charge will decrease a lot as
they get close.  It takes a long time at 13.5 to get to 100%.   The
other charging program is 14.2 or something like that until the current
drops, but charging at such a high level after it is charged will
damage it.

In my view, the most important thing is not to overcharge.  UPS service
is very rough on batteries, I think because of heat and overly
aggressive charging.

I don't think it matters much if your batteries are at 80% 90% or 100%
charge when inserted.

>> When all the batteries are "balanced" in the parallel string, I then 
>> install them into the battery tray(s) or directly into the unit.
>
> The goal there is to get them all to the published trickle charge voltage
> before installing them in the UPS.

I think Harlan's goal is to not have high-rate charging in the UPS, and
for them to have  a similar state of charge.   This is particularly
important if batteries are in series, as many units have 2 or 4.   THey
all have the same charge current then.  However, charging is more
efficient at lower state of charge, so they tend to balance.   THis is
much easier than lithium which seem to need explicit balancing.

>> Sometimes I will take the "old" batteries and run them thru the above 
>> process to see if they will "recondition".  Sometimes we will use these 
>> for lighting or other non-UPS tasks.
>
> Which makes me consider my next steps: disposal. There are a number of
> commercial battery centers nearby. I'll start calling around before showing
> up with 20 batteries. ;)

I would expect that many places are happy to take them because the cost
of accepting batteries and recycling is probably less than the cost of
lead mining.  My local Advance Auto Parts has been willing to take them
in small quantities; I have not tried large quantities.  Staples also
will take e.g. a 7 Ah, and I have not tried larger.