Multiple battery banks of different topology work fine charging and
discharging. Think about how you can do it and not how you can't.
Any takers?
-------------------------------------------------------------------------------------------------
John Blittersdorf via RE-wrenches [4] Thu, 06 Apr 2023 15:06:08 -0700
[5]
Multiple battery banks work well as long as you are consuming. When
charging the charge parameters change. I'm running 8 Interstate L16's,
1
Fortress e-flex, And 3 Simpliphi 3.8. With big switches between them. I
was using all three but changing charge parameters on
My two controllers and inverter got to be too much trouble. I ran all
with
lithium settings but I'm retiring the L16s and putting in a second
eFlex.
2 eFlex or 3 Simpliphis do a great job replacing the 8. The 3
simpliphis
will be leaving for their summer home at a fishing club. Hi
John B
On 2023-04-06 8:43 am, Dave Angelini Offgrid Solar via RE-wrenches
wrote:
And the next step for hi reliability offgrid is to have both types of
battery in there own independent inverter power systems. Just switch
the DC bus from one power system or the other. I like the LFP just
turned off sitting as a spare power system. You can rotate or do a
monthly test like it is a genset.
This is also a good way to use up the old flooded and retire it when it
becomes useless and ready to recycle. Some LFP manufactures do provide
a spare BMS but probably better to just have an extra battery at the
offgrid home.
Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail [email protected]
text 209 813 0060
On 2023-04-05 6:30 pm, Scot Arey via RE-wrenches wrote:
Just attended the NABCEP conference last week and took in CEU classes
from Rolls and Midnite on battery charging and design. Just awesome
classes and I walked away thinking the FLA were kind of like my old 7.3
Powerstroke diesel…I could work on them and could see when issues were
developing. The lithium batteries are kind of like my 6.7 PSD. Great
power, fast but when something happens with a BMS…no idea except to go
to the manufacturer.
Just wanted to share this after reading your awesome post.
Scot
From: RE-wrenches <[email protected]> On Behalf
Of Tump via RE-wrenches
Sent: Wednesday, April 5, 2023 6:24 PM
To: RE-wrenches <[email protected]>
Cc: Tump <[email protected]>
Subject: Re: [RE-wrenches] RE-wrenches] replace part of rolls battery
bank
I would suggest that adding additional batteries to increase battery
voltages is fine 48 to 54V or what ever, I too have used this many
times on very remote sites. Please also increase your inverters hi
voltage cut out settings, as this can be a real bummer having the
system shut down in full sun.
Another thing; IF you have battery strings, cables of equal length
from each string should be connected to a buss bar then buss bar to
inverter or inverters, this will reduce wiring headaches, voltage drop
as well as providing equal charging to all strings. (depending on
internal resistance).
I would also suggest fewer batteries of bigger cells. My preference is
2 volt cells, less holes to water, less copper interconnects. Yeah
there heavy but for hi charging & discharging, a large battery is
always my choice. OR the Surrette 6CS25P has been the MOST reliable
battery Surrette has put out. After almost 30 + years of installing
their batteries this one has been the best. They do have a EX series 2
Volt cell that has the same plate thickness as the 6 CS but I have had
issues w/ them. IF you are using the EX 2 volt check the polarity PRIOR
to installing them & mark the positive side. I have had the plastic
covers installed incorrectly and it plays havoc on your install.
Yep LEADITE I am, refractometer and a DVOM and I have a client that can
spot problems way before things become critical. AND that Surrette
warrantee Pit BULL Mr. Higgins & your client will be very happy when
Steve OKs a replacement because you have recorded your Spg readings.
My $.02 TUMP
On Apr 5, 2023, at 5:26 PM, greg egan via RE-wrenches
<[email protected]> wrote:
Danny, My experience is if you are careful and use equal length
conductors for all 3 strings you can get good results. The main
problem I have with 3 strings of 6 V cells @ 48 vdc is leaving the
customer with 72 cells to check and fill. That's a lot of work if you
don't have a watering system.
I totally get why you'd want to give them 2 strings in case they lose a
battery or 2. Most of my off grid customers live quite a ways from the
battery store and it's not uncommon for it to take a month to get
replacements - during the best of times.
Another option I've done is give them a string of 25 - 2V cells for a
48V system. You just set the charging parameters accordingly and go.
That way if they lose a cell or two, the remaining battery bank should
be able to keep them limping along until the replacement battery(s)
show up. Need to check and make sure your charge controller and
inverter can charge at the slightly higher V but usually that's not a
problem.
Best,
Greg Egan
Remote Power Inc.
[email protected]
Message: 1
Date: Tue, 4 Apr 2023 20:45:44 +0000
From: Daniel Young <[email protected]>
To: "[email protected]" <[email protected]>, RE-wrenches
<[email protected]>
Subject: Re: [RE-wrenches] replace part of rolls battery bank
Message-ID:
<bl1pr12mb5921cde5991f65fa842bc82cbb...@bl1pr12mb5921.namprd12.prod.outlook.com>
Content-Type: text/plain; charset="utf-8"
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)
[email protected]<mailto:[email protected]>
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org [1]
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
"We must all learn to live together as brothers,
or we all will perish as fools."
MLK
Tump [2][email protected] www.SWNL.net [3]
Solarwinds Northernlights _ _
_ Serving Mid Coast Maine & Northern California_
_ 207-832-7574 Cl. 610-517-8401
_
_ __Blair "TUMP" May_
******** MAINE'S CHARTER ********
_ NABCEP "Certified PV Installer"_
******** MAINE'S CHARTER ********
_ Trace Xantrex "Certified" Dealer / Installer"_
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try
the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
Links:
------
[1] http://re-wrenches.org/
[2]
blocked::mailto:[email protected]%22%20%5Co%20%22blocked::mailto:[email protected]
[3]
blocked::http://www.swnl.net/%22%20%5Co%20%22blocked::http://www.swnl.net/
[4]
https://www.mail-archive.com/[email protected]&q=from:%22John+Blittersdorf+via+RE%5C-wrenches%22
[5]
https://www.mail-archive.com/[email protected]&q=date:20230406_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
