[RE-wrenches] FLA battery problelm

[Steve Higgins]

The SW series inverters don't have non-volatile memory, so if the renter
discharges the battery below the low-voltage point, all settings will be
reset to default.   That will definitely cause charging issues.

If they were overfilling the batteries, this would push sulfate out of the
battery, diluting the acid mix and lowering overall capacity.   You can try
adding more back, but it will require a lot of premixed acid. It might help
to drain 1/2 out and add back premixed 1.265-1.280 acid to correct. If the
sulfate levels are already low and there is mostly just water in the
battery, corrosion can occur within weeks, resulting in permanent damage.

Also, if you add too much or the sulfate has precipitated on the plates,
this will increase the sulfate in the battery and lead to a significant
loss of overall capacity.

My guess... is this battery is done for... You can try the above, but
you'll likely spend a lot of time adjusting electrolyte levels and many
hours of cycle charging to recover.  Even if you recover to some capacity,
the SGs will always be "All over the place," and the bank will likely
remain questionable until they are replaced.    In the end, the "Renter"
probably killed these due to lack of interest/education...

Steve Higgins.

On Fri, Dec 12, 2025 at 10:21 AM David Coale via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Hi Wrenchers,
>
> I have a client with an old off-grid Trace system and he is having trouble
> with the batteries.  He has HUP Solar One FLA batteries that are about 4
> years old, so they should be in good shape.  The last set lasted almost 20
> years with a fair amount of abuse.
>
> Here is he history and what I think is going on. 7/21 they got new
> batteries after about 19 years of use.
>
> 7/22 I get a call saying the batteries are not charging up all the way.
> When I check out the system, the batteries needed cleaning, and I found
> three low cells, and the charger settings were back to default, not set
> high enough to charge the batteries all the way (it’s always multiple
> problems).  The client (now a new renter, new to the system) said he was
> filing the batteries once a month and experienced some overflowing when the
> batteries were charged up.
>
> I cleaned things up, reset the charging parameters and set up an
> equalizing charge to even out the cells. Hopefully this will fix things.
>
> 11/25. The client calls and said the batteries don’t charge up all the way
> and he is running the generator a lot and worried about getting though the
> wintertime.
> When I check things out, there are three bad cells and there is soda on
> the batteries. It is hard to get a good voltage readings because of the
> soda. Most of the cells are reading 2.1 volts under about a 40 amp load.
>
> Yesterday I check things out, and all the cells are reading between 1.93
> to 1.98 under a 40 amp load in the morning, and I don’t find any bad
> cells.  The charging voltage is never going over about 52 volts so the
> system is never getting fully charged up.  The charge setting look OK, so
> not sure what is going on. This is acting like an old battery pack but
> these batteries are relatively new.
>
> My guess at this point is that maybe the batteries lost acid with the
> overflowing event and lost capacity.  Maybe adding acid back in would bring
> them back up to working order.  The SG measured at 1.150 or less.
>
> At this point the client (renter) has had enough of these battery problems
> and is wondering every morning if the batteries will last long enough to
> until the sun comes up.  The renter is pushing for a replacement LFP
> battery, but there should be lots of life left in this battery pack.
>
> Let me know what you all think.
>
> Thanks,
>
> David
>
>
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