Jay Sorry I should have explained that too... Absorb starts off at around 50% of the available amps and tapers down to around 20% So I divided 20 by 50 = .40 there's a 5% loss factor hence .42
Tom Duffy Senior Solar Design Engineer Toll Free 888-895-8179 t...@thesolar.biz Customer Service and Accounting 888-895-6810 Grid tie sales 888-895-7847 Off Grid sales 888-895-4058 Other Product Sales 888-895-9612 Central America Sales (Panama) 507-6-126-1253 Shipping and Receiving 888-895-6497 Tech Support 888-895-8179 SKYPE: thesolarbiz -----Original Message----- From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jay Peltz Sent: Monday, July 22, 2013 1:27 PM To: RE-wrenches Subject: Re: [RE-wrenches] Trojan L-16s Hi Tom Where did you get the .42 from? Jay Peltz power Sent from my iPhone On Jul 22, 2013, at 11:04 AM, Tom Duffy <t...@thesolar.biz> wrote: > Drake > > Keep the absorb rate recommended for the CC. The trimetric strays over > time and will become accurate again when you overcharge (equalize) > > The math: > Amp hours of battery @ 20 hour rate divided by max charge available in > amps, from whatever you using to charge (solar or inverter/charger) > Times .42 = absorb time in hours > > i.e. your system 980 watts, 980 divided by 28.8 (average volts) = 34 > amps max charge > 370 AH divided by 34 = 10.88 X .42 = 4.57 round up to 4.6 hours absorb > time for the CC Your inverter VFX3524 max charge 85 amps... 370 > divided by 85 = 4.35 X .42 = 1.82 absorb time for the inverter/charger > when running generator > > Tom Duffy > Senior Solar Design Engineer > > Toll Free 888-895-8179 > t...@thesolar.biz > Customer Service and Accounting 888-895-6810 Grid tie sales > 888-895-7847 Off Grid sales 888-895-4058 Other Product Sales > 888-895-9612 Central America Sales (Panama) 507-6-126-1253 Shipping > and Receiving 888-895-6497 Tech Support 888-895-8179 > SKYPE: thesolarbiz > > -----Original Message----- > From: re-wrenches-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Drake > Sent: Monday, July 22, 2013 10:04 AM > To: RE-wrenches > Subject: Re: [RE-wrenches] Trojan L-16s > > Hi Larry, > > I will bump up the absorb voltage to 29.6 V. How long do you think the bank > should stay in absorb at that rate? The bank now seems healthy, with the bad > battery replaced. It does accept charge, without going high prematurely. > The max charge rate from the array is around C/10. The system can also be > fast charged from a Honda 6500 inverter generator through the Outback 3524 > VFX. > > We have a Trimetric meter on the system. The discrepancy between the percent > charge and the voltage is what demonstrated that we had a problem. > > Thanks, > > Drake > > > > At 09:30 PM 7/19/2013, you wrote: >> Hi Drake, >> >> It always concerns me when I hear that a battery bank reaches absorb >> setting very quickly. It typically means one of two things: very few >> AH were removed from the bank; the battery bank has sulfated cells >> due to chronic undercharging. Far too often I find the latter to be true. >> >> Healthy batteries will accept current and hold the charge voltage >> down with a fairly linear, slow climb to absorption voltage. Sulfated >> batteries do not accept current well which allows voltage to climb >> rapidly as the battery presents little load on the charging system. >> I'm not sure how this plays into your original post about a bad cell >> but it seemed worth mentioning. >> >> My opinion is to aggressively charge, by using higher voltage, large >> flooded batteries. This is especially true when the PV system is >> moderate or undersized. 29.6 volts is what Trojan recommends. You can >> go as high as 32 volts on the L-16's but make sure the temperature >> compensation is installed properly and working. You will use more water. >> >> One last comment, I highly recommend that ALL off grid systems have a >> battery capacity monitor installed. It's kind of like flying an >> airplane without a fuel gauge...it might not end in disaster. >> >> Larry Crutcher >> Starlight Solar Power Systems >> >> >> >> On Jul 18, 2013, at 1:11 PM, Drake >> <drake.chamber...@redwoodalliance.org> wrote: >> >> Tom, >> >> The batteries usually reach absorb voltage shortly after the sun hits >> the array. The reason the bank wasn't working correctly is that one >> cell was dead in one of the batteries. >> >> I could increase the absorb time to 4.6 hours and the voltage to >> 29.6, especially since the bank has a new battery. That is longer and >> higher than I'd previously heard recommended. >> What would be the effect on water >> consumption? How did you calculate the absorb time? >> >> Thanks, >> >> >> Drake >> >> _______________________________________________ >> List sponsored by Home Power magazine >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Change email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out participant bios: >> www.members.re-wrenches.org > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Change email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Change email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
