32V seems a bit high - even for an infrequent equalise I'd not go over 30Vmax - and then with a low current limit or approach it very slowly. I stuffed a (12V VRLA) battery up a while ago with a 14.5V charge & got thermal runaway. Not a deep cycle type though. Adding bicarb will increase the PH of the electrolyte (decrease the acidity) and utimately stuff things up totally. The battery won't get sulphated if it's not left discharged for a reasonable length of time. I've been doing tests on batteries lately due to my scooter batteries wearing out and it seems to me that a higher charge voltage just charges the batteries quicker - the capacity when fully charged is pretty much unchanged. But that's by varying the charge voltage from 54 to 56V ("48V" battery). Equalising at 58V did appear to help a little - but I've ordered replacements anyway as I now have to charge the battery after every 6km trip, rather than daily (12km). But it sounds like the guy concerned won't be told so will have to find out the hard way. RP On 13 February 2014 10:49, IVP wrote: > I had a call this morning from someone I (unfortunately) know, who > Russell is aware of too. Someone whose depth, or lack, of knowledge > about electrical matters is quite hard to describe. He frustrates me so. > > He asked me how to adjust his solar regulator up to 32V, rather than > the 28V set by the installer. He claims that 32V "will add 10A to the > charging and won't harm these deep-cycle batteries at all". He has a > knack of alienating people, so the installer won't come back to do it > free of charge. My caller has the unit and instructions, not much I can > do from here, even if I wanted to. > > It's one of these. AFAICT, they are meant to be set to ~ 28 - 29V. > > > http://www.chinasolarregulator.com/solar-controller-1215-2215-3215-4210-e= tracer-mppt-dual-battery-charge-controller.html > > He's probably seen the "Max battery voltage, 32V". Based on what > I've read in this thread so far, I feel he's sacrificing the batteries fo= r > some apparent short-term gain and isn't going to get the wanted 10 > years out of these batteries. Am I wrong ? > > Then he claims that he rejuvenates his batteries by adding bicarbonate > solution. Desulphates them, he reckons - "you can see it fizzing off". > Chemistry 101 says what happens when you mix an acid and a base. > In this case the fizzing is a lot of CO2. Apart from the addition of a > few sodium ions, I just can't see how neutralising the sulphuric acid > improves a battery. > > Joe > > -- > 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 .