Because you are pulling more energy from a given cell. Current typically flows in one direction at a time. If you are pulling current off of the whole system all the time, AND pulling more from part of the system, then there is never a chance for the system to come back to equilibrium. Think of it like having four tanks of water each connected with siphon hoses. If you have two hoses pulling water from one of the tanks, it will drain faster than the other three tanks with only one hose. Your charger doesn't realize that one cell is being drained faster as it is only looking at total voltage across the system.
Cameron On Thu, Oct 18, 2012 at 10:36 AM, Tim Kerns <[email protected]> wrote: > I just put up 2 new solar panels yesterday to replace 2 that were now > to small of wattage to cover the expanded load at the tower. > > Panels with no load were putting out 35 vdc, at the batteries with load I > was seeing 28 vdc. > > I use the tycon voltage regulator to maintain 24 vdc to the radios. Added > cost, yes, but this is a remote site with important backhaul and I don’t > need to burn a radio out. > > I was also taking 12 vdc from one of the batteries, but found it would > drain it in about 2 weeks... the batteries do not charge evenly, maybe one > of our EE members can explain this. > > 4 12 vdc batteries, 2 in series, then the 2 sets in parallel., most > equipment is taken from the 24 vdc, one switch takes power from the 12 vdc. > Why does this not keep all batteries charged equally, when using the solar > at +27 volts. > > Tim Kerns > CV-Access, Inc. > > > *From:* Josh Luthman <[email protected]> > *Sent:* Thursday, October 18, 2012 7:49 AM > *To:* WISPA General List <[email protected]> ; [email protected] > *Subject:* Re: [WISPA] Another Ubiquity question > > > Because batteries are 27v. > On Oct 18, 2012 10:45 AM, "Faisal Imtiaz" <[email protected]> wrote: > >> Call me Stupid... but what is the point of this discussion ? >> >> Operating the Radios @ 27V is exceeding the Mfg. Specs. ..... >> Will they work ? maybe... >> Will they fail ? maybe.... >> If you burn them up..... you are on your own.. ? or at least at >> UBNT's discretion, since you are voiding the warranty, by operating our >> of Specs. >> Will it shorten the life of the Radio ? maybe... >> Will is just work fine ? maybe..... >> >> This reminds me of the discussions on the CPU Over-Clockers Forum...... >> If you want to play, sure nothing wrong with that.. but you are on >> your own .. >> If you expect it to preform well for a long time, then it is best to >> stay within the Mfg. Specs ... >> >> I have often said this to folks.... In our industry, when you exceed >> Specs.... things don't just 'break'.... but they do start doing 'funky >> stuff'.... >> >> Of Course YMMV >> >> :) >> >> Faisal Imtiaz >> Snappy Internet & Telecom >> >> On 10/18/2012 10:06 AM, Justin Wilson wrote: >> > We see 27.3 volts at the battery. And 27.1 volts at the top with >> no load. >> > Obviously load will have an impact on this. >> > >> > Justin >> > >> > -----Original Message----- >> > From: Jeromie Reeves <[email protected]> >> > Reply-To: WISPA General List <[email protected]> >> > Date: Thursday, October 18, 2012 9:15 AM >> > To: WISPA General List <[email protected]> >> > Subject: Re: [WISPA] Another Ubiquity question >> > >> >> That depends on wire size. That distance is not going to be ethernet >> >> so I will assume #12 AWG, 400ft, copper wire, etc. You should be >> >> seeing a 5.6% drop under a 1amp load or about 25v under load. >> >> >> >> >> >> On Thu, Oct 18, 2012 at 6:02 AM, Justin Wilson <[email protected]> wrote: >> >>> 27 volts at the base. DC has very little loss over 400-500 >> foot >> >>> distances. We are seeing about .1 volt loss on a 400 foot run. >> >>> >> >>> -----Original Message----- >> >>> From: Scott Lambert <[email protected]> >> >>> Reply-To: WISPA General List <[email protected]> >> >>> Date: Thursday, October 18, 2012 12:16 AM >> >>> To: <[email protected]> >> >>> Subject: Re: [WISPA] Another Ubiquity question >> >>> >> >>>> On Wed, Oct 17, 2012 at 10:14:03PM -0400, Justin Wilson wrote: >> >>>>> Many UBNT deployments running at 27volts of clean DC power. Not >> >>>>> saying it's ideal but it works. >> >>>> 27v at the ethernet port or 27v at the base of the tower? >> >>>> >> >>>> -- >> >>>> Scott Lambert KC5MLE Unix >> >>>> SysAdmin >> >>>> [email protected] >> >>>> _______________________________________________ >> >>>> Wireless mailing list >> >>>> [email protected] >> >>>> http://lists.wispa.org/mailman/listinfo/wireless >> >>>> >> >>> >> >>> _______________________________________________ >> >>> Wireless mailing list >> >>> [email protected] >> >>> http://lists.wispa.org/mailman/listinfo/wireless >> >> _______________________________________________ >> >> Wireless mailing list >> >> [email protected] >> >> http://lists.wispa.org/mailman/listinfo/wireless >> >> >> > >> > _______________________________________________ >> > Wireless mailing list >> > [email protected] >> > http://lists.wispa.org/mailman/listinfo/wireless >> > >> >> >> _______________________________________________ >> Wireless mailing list >> [email protected] >> http://lists.wispa.org/mailman/listinfo/wireless >> > ------------------------------ > _______________________________________________ > Wireless mailing list > [email protected] > http://lists.wispa.org/mailman/listinfo/wireless > > > _______________________________________________ > Wireless mailing list > [email protected] > http://lists.wispa.org/mailman/listinfo/wireless > >
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