So the 24 batteries are actually 72 individual cells that are trying to
charge equally, with essentially no BMS. Its not just max strings, but
max # of cells, and that's double my maximum.
You mentioned they use it pretty hard, so that's the other big part of
how long L16s will last. If the customer is barely using the available
capacity, I've seen batteries last closer to 10 years, but in this case,
I think the remaining cells are close to finished. I'm into using
batteries for as long as possible as well, but customer and installer
suffering come into play, as well as the fact they'll use much more
water at the end of life, and cause a lot more corrosion damage.
Not to be a turd at the pool party, but its not reasonable to plan on
another 2 years of service. My guess is that you will probably have
more cells fail by the time you return with the prorated warranty
replacements. Certainly rolling into the summer months, more cells are
going to start failing like pop corn. (Pop, pop, pop)
Fortress is a good battery, but some of the programming, (especially
LVD) can be tricky with older inverters. I had to use the aux out on
the CC to switch off the inverters. IF the inverters are Outback, they
have a remote switch, if its something else, you might have to actually
switch off a relay on the AC output.
Ray
On 4/4/2023 2:45 PM, Daniel Young via RE-wrenches wrote:
Thanks all for the advice. I figured it was not worth trying on a
different battery brand. I honestly needed to be able to tell them I
researched it and asked my peers.
The client really uses the 3 x strings they have and did not really
want to go down to 3. They are currently choosing to get the two Rolls
under the prorated warranty, and hopes to get another 2 useful years
out of the bank before planning to replace.
Already prepared him on the cost of the equivalent Li+ at todays
prices. So he knows roughly where he is heading.
Side note: I am in the camp of trying for 2 x strings when possible
(agree that 3 x strings is the absolute limit, and not the best
option), simply because if a single cell goes bad, I don’t want a
client with essentially nothing available until we can get a
replacement and get on site. With 2 strings, they can make due at
least. That’ll go out the window with Lithium though. Looking at
Fortress Power for the next battery bank for this client. But we will
see what changes in the market by the time it’s needed.
With Regards,
--
Danny Young
NABCEP PV Installation Professional #031508-90
Engineering Team Lead
Solar Energy Solutions
Lexington | Louisville | Bloomington | Cincinnati | Evansville |
Indianapolis
513-448-5176 (mobile)
877-312-7456 (Main Office)
da...@sesre.com
*From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On
Behalf Of *Dave Angelini Offgrid Solar via RE-wrenches
*Sent:* Monday, April 3, 2023 4:34 PM
*To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
*Cc:* Dave Angelini Offgrid Solar <offgridso...@sti.net>
*Subject:* Re: [RE-wrenches] replace part of rolls battery bank
5 years old on 3 strings, it might not matter to mix, better get ready
for a new bank.
I have never used more than 1 string for my clients and get closer to
10 years life, so maybe there is better advice out there.
Good Luck!
*Dave Angelini Offgrid Solar*
*"we go where powerlines don't"*
*http://members.sti.net/offgridsolar/*
*e-mail offgridso...@sti.net*
*text 209 813 0060*
On 2023-04-03 11:03 am, Daniel Young via RE-wrenches wrote:
Hello Wrenches,
Have a client with 24 x Rolls S550’s. 2 of the batteries have
given up the ghost. Rolls will replace them under the pro rated
warranty.
The issue us, the client is wanting to replace them with non Rolls
batteries to save $. They can get 400AH 6V L-16 form factor FLA
batteries from a local battery house for the same price I am going
to get the new Rolls for. And that also means they don’t need to
pay for freight. The net result is that they could save $4-500 by
getting the batteries locally. No freight, and no markup on the
batteries we provide (I can technically add the lost markup back
in as labor, we do need to make something off of the 3hr one way
drive to swap the batteries)
Question is, has anyone got experience mixing battery brands like
this?
3 x strings of 8 c S550’s (L-16HC would be the replacements) both
dead batteries are on the same string.
Whole battery bank is near the 5yr old mark.
The last rolls battery bank the client had lasted them 10 years.
(they baby the battery bank to be sure, and take maintenance
seriously)
I understand where the client is coming from, but do not want to
let them shoot themselves in the foot, and I simply do not know
what the chances are of swapping in batteries from a different
brand. In my head, I don’t see a big issue, even if they are sub
par, they will likely just get older faster, and fail around the
same time as the rest of the 4-5yr old battery bank. But I’m
unsure if there are any more subtle issue that these other
batteries would cause.
Client has been loyal for more than a decade, so I want to give
them a fair shake at saving some $ now, as they plan to move to
lithium when the whole battery bank finally gives out.
With Regards,
--
Danny Young
NABCEP PV Installation Professional #031508-90
Engineering Team Lead
Solar Energy Solutions
Lexington | Louisville | Bloomington | Cincinnati | Evansville |
Indianapolis
513-448-5176 (mobile)
877-312-7456 (Main Office)
da...@sesre.com
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