Sad to hear about the damage. Batteries can be floated at manufacturer's rcommended voltage but not "trickled" with current such that the voltage rises to or above boost levels when electrlysis and loss of electrlyte will occur. I'd guess that your "trickle charging" has had enough energy available to hold the battery at or above boost voltage levels. I do not know the mechanism of dry-out damage. When you replace them the old ones may be able to be partially restored and used in a lesser role - various solar power and off grid groups probably have experience in this area. . Battery data sheet here: http://www.ritarpower.com/upimg/20151211154018926.pdf http://www.auviras.lt/out/media/Ritar-RA12-100.pdf.pdf RA12S http://www.innovative.co.nz/pdf/RA12-100S.pdf Some good information in the data sheet. The recommended float voltage is 13.6 to 13.8 V They can be maintained there indefinitely. Boost voltage is 14.6 - 14.8 V - this is for bringing them to full capacity after a CC CV charge BUT tyhey MUST NOT be left there. They say lifetime in flaot service is 9-12+ years at 10C 5-8 years at 30 C 2-5 years at 40C. So: When not in desert keep in cool place. They say: RITAR Valve Regulated Lead Acid (VRLA) batteries can be stored o for more than 6 months at 25 C. Self-discharge ratio less than 3% o per month at 25 C. Please charge batteries before using. ____________________ Some of this MAY be useful: http://batteryuniversity.com/learn/article/how_to_restore_and_prolong_lead_= acid_batteries Also just maybe this. Stirring up / homogenising the acid as it reconstitutes MAY help. One can hope. http://batteryuniversity.com/learn/article/water_loss_acid_stratification_a= nd_surface_charge *Google search lead acid boil dry damage L*ots of advice. SOME may just possibly be good. Much doesn't seem to be. Russell On 11 June 2017 at 19:37, Justin Richards wrote= : > Purchased 2 x RA12-100 100Ah valve regulated batteries for camper trailer > approx 18months ago. > > They have never been pressed into serious service and mostly been on > trickle charge (big mistake) via a 33w solar panel partially shaded and n= ot > orientated correctly. Regular checks show approx 13v. > > Now out in the Australian desert batteries initially behaved perfectly. > Then they failed. > > Thought i would share my experience as I have some time watching the bike= s > go past. > > Popped the glued down regulator cover and discovered they were dry. > > So, never trickle charge, and check levels even if they are sealed. > > We are out camped along the Finke Desert Race so i am try to breath some > life back into them. Need to run the 5A fridge. > > I am constantly monitoring terminal voltage and at times it bounces aroun= d > like it it virtually open circuit at other times it presents as a stiff > load or how a battery should behave. > > Sometimes i NEED (run water pump or start fridge) it to behave so i find = if > i load it up with a 2 ohm load the voltage drops, bounces between 8-9V th= en > after awhile will jump to approx 12v. If lucky i can then connect the > fridge and works like a charm for maybe an hour or so. > > I get fooled into thinking they are comming back to life but alas I have = no > choice but to replace them. > > So wisdom of the internet seemed to be the less they are deep cycled the > longer they last and always made sure these were never discharged too muc= h > while the whole time i was over charging them. > > Not sure what the best way forward is for these batteries while the campe= r > is parked up months at a time. > > Perhaps a timer that gives them a charge every month or so. > > Justin > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .