[RE-wrenches] Outback MX-60 - Li-ion charging
Steve Higgins
steve at surrette.com
Wed Dec 1 16:09:35 EST 2021
I have found this to be true as well, especially when multiple LFP battery
blocks are in parallel . I like to see the charge rate around the C2 to C8
Rate... the lower the charge rate the longer the absorb. On the LFP's we
advise around 20-60 mins absorb time again depending on the amount of
current availability, and quantity of parallel connections.
With the MX60 you can adjust the float voltage to the 3.65vpc, and set the
timer for the rest of the solar day to ensure the batteries are getting
balanced...
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
<http://www.rollsbattery.com> <http://www.rollsbattery.com>
Steve Higgins ⋅ Technical Services Manager
t +1.902.597.4020 m +1.206.790.5840
f +1.902.597.8447 e steve at surrette.com
<#m_4615892711811776411_SignatureSanitizer_SafeHtmlFilter_>
<http://www.facebook.com/RollsBattery>
<http://www.facebook.com/RollsBattery> <http://www.twitter.com/RollsBattery>
<https://www.youtube.com/user/RollsBattery>
<https://www.linkedin.com/company/rolls-battery-engineering>
<http://www.instagram.com/RollsBattery>
<http://www.instagram.com/RollsBattery>
<http://www.instagram.com/RollsBattery>
------------------------------
<https://web.cvent.com/event/b25b313d-fc01-4ce3-87e6-4971a81d5199/summary>
*Register using 10% discount code **ROLLS22*
------------------------------
CONFIDENTIALITY: The information transmitted herein is intended only for
the addressee and may contain confidential, proprietary and/or privileged
material. Any unauthorized review, distribution or other use of or the
taking of any action in reliance upon this information is prohibited. If
you receive this email in error, please contact the sender and delete or
destroy this message and all copies.
------------------------------
On Wed, Dec 1, 2021 at 12:24 PM bob at midnitesolar.com <bob at midnitesolar.com>
wrote:
>
> Thanks Larry.
>
> The information to stop when absorb voltage was reached is like, 10 or
> more years old and so I
> don't know if that voltage reach and stop charging algorithm is still used
> by any BMS's.
>
> This is probably why we had to add a logic input to tell the controller to
> stop charging from the BMS.
>
> After the 0.3 hours at Absorb for balancing (which makes perfect sense for
> a BMS), does the MX/FM then
> go to float at 3.65V per cell after that ?
>
> Does your systems just restart a new bulk/absorb cycle the next morning or
> do you also do a Re-Bulk if
> or when battery voltage falls below a certain point ?
>
> Also, listening (reading) chat here on what might be needed that may not
> have been addressed by
> Li battery, BMS and/or charge controller manufacturers.
>
>
> Thanks,
> boB
>
>
>
>
>
> On 12/1/2021 12:03 PM, larrycrutcher wrote:
>
> If you stop charging a Li-ion battery when the CV (absorb voltage) is
> reached, you may reduce or stop the needed cell balancing time. We have had
> customers develop unbalanced series cells from continuous undercharging.
> Because of internal cell resistance, one cell will always reach saturation
> before others in the group. This can happen at less than 1mv difference.
> The more unbalanced a group of series cells are, the sooner one cells
> voltage will spike causing over voltage events at a lower terminal voltage.
>
>
> Our Li batteries (Elite Power Solutions-GBS and LiFeBlue) can be held at
> 3.65Vpc continuously, no problems. We have customers using both MX and FM
> controllers for 8 years now. Our recommended setting for the Absorb timer
> is 0.3 hours. This allows for cell balancing and for the capacity meter to
> recalibrate. Some chargers will stay at CV for several hours. No problems
> doing this either as long as cell voltage is lower than 3.8V (LFP chem.).
>
> Larry Crutcher
> Starlight Solar Power Systems
>
>
>
> On Dec 1, 2021, at 9:38 AM, bob at midnitesolar.com wrote:
>
>
>
> Depends on the requirement for the BMS.
>
> Usually, but not 100% always, the requirement is to get the voltage up to
> "absorb" and then stop charging.
>
> Just set the min and max times very low, like 1 minute and that should
> satisfy that one.
>
> I do not remember if the MX60 had a Re-Bulk setting but I think it did ?
>
> The MX did not have a logic input for turning it on and off of course. OB
> had a communications
> device that converted their communications protocol to Modbus or Ethernet
> I think it was which
> may (or may not) be able to make it work.
>
> Could always buy something newer and keep the MX60 as a spare.
>
> boB
>
>
>
> On 12/1/2021 9:10 AM, frenergy wrote:
>
> boB,
>
> Interesting...Sounds like this is not a candidate for L-ion
> batteries.
>
> Bill
> On 11/30/2021 10:47 PM, bob at midnitesolar.com wrote:
>
>
> Hi Bill....
>
> As I remember, the min is of course... Minimum time in Absorb.
>
> Max is maximum time in absorb but depended on how long it took to get from
> Bulk MPPT to that Absorb voltage.
>
> So if it took 3 hours to get to Absorb that morning and you had t set for
> Max 2 hours, it would Absorb for 2 hours.
>
> If it only took 1 and 1/2 hours to reach Absorb voltage, the MX60 would
> Absorb for 1 and 1/2 hours.
>
> It worked "OK" but these days I would probably just set it for min of
> some 2 or 3 hours and then a max could be the same
> time or longer for FLA batteries.
>
> boB
>
>
>
> On 11/30/2021 7:16 PM, frenergy wrote:
>
> Yes, the old one, not the FM. This oldie had an interesting way to set
> the absorption time. You would set the "min" time (in minutes) and you
> would set the "max" time (in hours, you have to set it to 1,2,3 or 4 hours).
>
> I need to know if I set the "min" to 10 minutes and the "max"
> time to one hour or two or three or four, how long will it stay in absorb?
>
> I called Outback and Megan there didn't know how this old fart
> works, apparently tech support isn't supporting us their old relics.
>
> Bill
>
> Feather River Solar Electric
> Bill Battagin, Owner
> 4291 Nelson St.
> Taylorsville, CA 95983
> 530.284.7849
> CA Lic 874049
> solar powered since 1982
>
>
>
>
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon> Virus-free.
> www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link>
>
>
> _______________________________________________
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> 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/re-wrenches@lists.re-wrenches.org/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: RE-wrenches at lists.re-wrenches.org
>
> 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/re-wrenches@lists.re-wrenches.org/
> 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
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches_lists.re-wrenches.org/attachments/20211201/264a4766/attachment.htm>
More information about the RE-Wrenches
mailing list