Most AGM's don't like voltage that high and it swells the battery and destroys its storage capability alot of the time Jerry
On Fri, Jul 22, 2022, 7:50 PM Steve Higgins via RE-wrenches < re-wrenches@lists.re-wrenches.org> wrote: > 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 > <#m_-3124562702126219588_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. 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