William, If the battery cases swelled, they saw over 52 degrees C temps for quite some time.
While the swelling is usually only cosmetic, what's happening inside is the negative plates are starting to burn. This is where you will start to lose capacity and life cycle... Extended temps of just 35C will half the overall battery life. One of the issues with the Outback gear is they only temp compensate at 5mv/Degree/cell. For all the AGM batteries I know of, you need to temp compensate at 4mv. In hot temps, this should help, but cold temps could result in an overcharge. Did you check the BTS and make sure it was operating properly? Another issue is that BTSs are often placed on the top or lug of the battery, The top of the battery is about 5-10 deg C cooler than 1/2 way down the side of the battery, Which will also cause problems with proper temperature compensation, especially with warmer/colder extremes. Any kind of sulfation will cause an imbalance when you mix old and new batteries. I'm not a fan of mixing any age AGM batteries as there is no way to tell what the SOC of the old bank vs. the new bank is. They are not like flooded batteries; you can check SGs and dissipate heat much better than AGM or GEL batteries. I discourage doing this if you can. I probably wouldn't have mixed the old and new in the same strings. This way, you keep the higher resistance batteries in a single string, Lastly, bunching them together with no spacing between them is very bad. Batteries should be in a cool, dry environment. Most battery companies want to see 1-3 inches in between each battery to allow for effective cooling. When they are all bunched up together, that is a lot of thermal mass that doesn't have much chance of cooling. I have seen two parallel strings of AGMs take 24-36 hours with no charging or load to drop from 45c to 25C! Hope this helps! Have a good weekend. <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> <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 st...@surrette.com <#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> ------------------------------ 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 Fri, Jul 22, 2022 at 6:48 PM William Miller via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > Friends: > > > > I maintain a system with 16 AGM L-16 batteries. Eight were installed in > September of 2021 and 8 were added in March of 2022. This is 5 months > apart. I have understood that when you install a string of batteries you > have one year in which to add another string before the first string ages > to the point it is contraindicated. When I added the second 8 I put 4 new > batteries and 4 old batteries in each string. > > > > About a third of the batteries are discovered to bulging on top. I assume > this means the batteries are damaged. I checked the FXR and Outback > Extreme Charge controller settings and all were set to absorb at 58.8, and > float at 55.2, as the manufacturer recommends. > > > > I downloaded the charge controller log and got 129 days of data. In that > log I see 68 days where the batteries exceeded 60 VDC. This is over half > the days. > > > > I wonder this: > > > > 1. Why did the voltage go up above 58.8 on so many days even though it > was set at 58.8. (I set the EQ voltage at 58.8 just in case, but EQ was > never engaged.) > > 2. Did the excess voltage damage the batteries? > > Any input is appreciated. > > > > Sincerely, > > > > William Miller > > > > Miller Solar > > 17395 Oak Road, Atascadero, CA 93422 > > 805-438-5600 > > www.millersolar.com > > CA Lic. 773985 > > > > > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@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@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
