I have to agree that the voltage is pretty aggressive for that system. With, absob timers they are typically based on how much current is going into the battery bank when in Bulk.
The inverter current realistically would be around 130 to 140 amps... at that rate 3.5 to 5 hours at the most... Generally I would have started around 4 hours and if the SGs sagged I would have added time, reduced time if the SGs rose above 1.275.... With the array, assuming they have around 6 kw of PV... that'll be around 100 to 120 amps of real current at peak, and to maximize pv production I may have set this to 4 to 6 hours. I still like to set the inverter charger .2 to .4 less in voltage than the solar charge controller. I have found, Even today most of the inverters and charge controller dont share true charging info. On Wed, Sep 12, 2018, 2:44 AM Mac Lewis <maclew...@gmail.com> wrote: > Hello wrenches, > > I inspected a system that another company had installed. It had single > string of 12 x Trojan L16RE-2V batteries about 2 years old. They had > experienced a battery melt-down. It looks as though the meltdown had > occurred internally, not from a bad connection. > > The system was dual stack Outback VFXR-3524A inverters (to be precise one > was a sealed unit). The set-points were as follows: > Absorb Voltage was 29.8V > Absorb Time was 6.0 hours > Float Voltage was 27.0V > Rebulk Voltage was 27.0V > End Amps was 0A > > These settings extended similarly to 2 x FM80 charge controllers. > > I was able to jumper the melted battery and get her power in 15 minutes. > Her installer had left her without power for 2 weeks. My clients will kill > me if that happened! > > Anyway, I believe these set-points are way out of whack and too > aggressive. The voltage is OK (Trojan recommends ~29.6V for this) but the > Absorb time seems way too long, Rebulk is too high and end amps isn't > helping. However, Im not finding a definitive article from Trojan that > describes typical Absorb times or even how to adjust towards a good Absorb > Time, based on specific gravity measurements or amperage absorption. > > My diagnosis is that these batteries have been cooked over the past 2 > years. In the electrolyte, there is noticeable "floaties". The client > said that the original installer had accused her of not using distilled > water, but I don't believe that would cause her symptoms. I believe the > floaties are plate material. > > I'd be interested in wrenches opinions familiar with these batteries if > these are appropriate settings for a low energy user. I will attempt to > get through to Trojan as well. > > Thanks in advance > > > > -- > > > > Mac Lewis > > *"Yo solo sé que no sé nada." -Sócrates* > _______________________________________________ > List sponsored by Redwood Alliance > > 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 > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > ,
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