[RE-wrenches] Off grid DC Loads: DC Converter

[Drake]

A Concorde AGM PVX 3050T recently failed in a 
bank of 8. Larry mentioned a couple of brands 
experiencing problems. These batteries are 4 
years old and have been kept in float in an off 
grid system, never stressed. Hopefully Concorde 
batteries are not going the way of Trojan L-16s. 
Has anyone else had problems with Concorde?


At 03:34 PM 1/16/2018, you wrote:
>Seems to me that you are on the edge for that size battery in winter. If
>the inverter is going to be on, converters are kind of nutty to me. I
>could see having one 24V for the freezer but... I only use Concorde AGM's
>when I have to. Is there an AH counter or Batt Mon?
>Good Luck
>
>Dave Angelini Offgrid Solar
>"we go where powerlines don't"
>http://members.sti.net/offgridsolar/
>e-mail  offgridsolar at sti.net
>text 209 813 0060
>
> > Answers to questions:
> >
> >
> >
> > The batteries are Discover EVL16A-A batteries. A single string of 8: 390AH
> > @48V nominal. We had one fail last year, showing a significantly raised
> > internal resistance when tested under a load then under charge. There is
> > another one showing signs of weakness, but currently under a 30A draw it
> > is only 0.12V lower than the highest battery in the mix, and 0.05V from
> > the average battery voltage. Readings were: 6.0, 5.88, 6.0, 5.93, 5.92,
> > 5.91, 5.93, 5.94 using a 1500W space heater as a constant load during the
> > test.
> >
> >
> >
> > There are more loads than just networking and security that the client
> > just recently disclosed. Gotta love the added loads to the design. There
> > is a satellite DVR, 2x4 camera webcam systems, cell modem, simplisafe
> > security system, chest freezer, 4 wifi range extenders to serve the less
> > reliable security camera system, and 26W LED dusk-dawn light. I have
> > already talked to them about thinking hard on what items can be removed
> > for the winter at least (DVR is going away, and one of the camera systems
> > too, likely the one requiring the wifi range extenders). All other seasons
> > the system is fine.
> >
> >
> >
> > As for the DC converter(s) we would get a voltage specific converter for
> > any unique voltages, depending on the # of unique items, we would likely
> > abandon that approach if it got to bee too complicated. But thank you to
> > all that provided guidance there. The meanwell units seemed to have the
> > right specs to do the job if we go that route. We would also install them
> > using a LVD of some sort, set somewhere above the standard low voltage
> > cutoff of the rest of the system. We would also only go this route if all
> > AC loads could be removed by doing this, allowing us to remove the 36w
> > idle draw of the Outback.
> >
> >
> >
> > With Regards,
> >
> >
> >
> > Daniel Young,
> >
> > NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90
> >
> >
> >
> > Lead Systems Designer for:
> >
> >
> >
> >  <http://www.dovetailsolar.com/> www.dovetailsolar.com
> >
> > Ph: 740-274-0139
> >
> >
> >
> > We’ve completed nearly 400 renewable energy projects!  Check out a few
> > in our photo gallery:
> > 
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> >
> > From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org] On
> > Behalf Of Starlight Solar Power Systems
> > Sent: Tuesday, January 16, 2018 11:08 AM
> > To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
> > Subject: Re: [RE-wrenches] Off grid DC Loads: DC Converter
> >
> >
> >
> > I too would like to know the make and model of batteries that are loosing
> > capacity. In the past 5 years we have experienced abnormally high failures
> > from 2 brands.
> >
> >
> >
> > Larry
> >
> > On Jan 15, 2018, at 2:00 PM, Jay <jay.peltz at gmail.com
> > <mailto:jay.peltz at gmail.com> > wrote:
> >
> >
> >
> > Can you tell us:
> >
> >
> >
> > Battery make,model and size?
> >
> >
> >
> > Jay
> >
> > Peltz power.
> >
> >
> > On Jan 15, 2018, at 12:32 PM, Daniel Young <
> > <mailto:dyoung at dovetailsolar.com> dyoung at dovetailsolar.com> wrote:
> >
> > Hello Wrenches,
> >
> >
> >
> > I have a client that is running into an issue with his off grid system.
> > The system is 3yrs old and they are starting to notice their AGM battery
> > bank is loosing capacity, in reality they are noticing the generator is
> > triggering more often. They want to try to lower the frequency of the
> > generator triggering if possible.
> >
> >
> >
> > The system is not occupied during much of the winter (unconditioned, which
> > further hurts the battery bank capacity), but the client has a security
> > system with a cell modem installed and always on. This fortunately allows
> > Optics-RE access, but unfortunately based on the FNDC shunt readings, is
> > pulling a consistent 150w from the battery bank. Currently the network and
> > security equipment is powered from standard wall-warts running on AC.
> >
> >
> >
> > I’d like to help the client extend the time between generator cycles by
> > taking the network loads and powering them directly from the battery bank
> > (the loads are all 12Vdc). Does anyone have any recommendations for a
> > decent quality DC_DC converter that would be applicable? Given inverter
> > losses and the efficiency of the typical wall-wart, I’d expect the
> > running loads to be closer to 80-100w rather than the 150w we see now. The
> > intent is to then take the inverter into search mode, or even switch it
> > off, to remove the tare losses there, and also to take all the wasted
> > power from the standard wall-warts and go to a single, more efficient dc
> > power supply.
> >
> >
> >
> > Any recommendations on a good DC_DC converter are appreciated.
> >
> >
> >
> > With Regards,
> >
> >
> >
> > Daniel Young,
> >
> > NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90
> >
> > Dovetail Solar and Wind
> >
> >
> >
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>Dave Angelini Offgrid Solar
>"we go where powerlines don't"
>http://members.sti.net/offgridsolar/
>e-mail  offgridsolar at sti.net
>text 209 813 0060
>
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