Hello, Drake & All~ Drake described his service dilemma about batteries bought elsewhere & whether to correct the original hinky pack wiring (copied below). My reply below may seem cynical & I may seem too eager to declare the existing battery as: "Failed". Call me jaded.
Mick's $0.02 is: If there's no amp-hour monitor in the system, I suggest you first try to persuade the homeowner to buy a metering shunt & a modest amp-hour meter such as the Tri-Metric--which could be used to measure & display the battery bank's amp-hour capacity. If the client won't approve that expenditure (& hourly labor for explanations), the service tech is hamstrung. Nobody can measure the health of a battery bank by just looking at it or talking about it...and clients sometimes receive the inevitable "battery bad news" if they are shown the diminished capacity on a digital display after an equitably managed "pump & dump". Your thought, Drake, of holding back on any re-wiring of the battery pack...seems prudent...until the first set of amp-hour measurements are recorded as a baseline. From there...a common pattern is a series of attempted remediation efforts--all for pay, of course--until the homeowner acknowledges that it's time to start afresh. Oops, I left out an important step: getting a read on whether the client has the money for new batteries or not. I'm personally terrible at getting that reconnaissance done early enough. If the client isn't materially blessed to be able to get new batteries, they might be better off spending limited funds on fuel for the engine generator instead of on battery testing & tutorials. The Wrench List is the Bomb~ Mick Abraham, Proprietor www.abrahamsolar.com Landline: 970-731-4675 Cell phone or for text messaging: 970-946-6584 > > ---------- Forwarded message ---------- > From: Drake <drake.chamber...@redwoodalliance.org> > To: RE-wrenches <re-wrenches@lists.re-wrenches.org> > Cc: > Bcc: > Date: Tue, 20 Nov 2018 11:41:17 -0500 > Subject: [RE-wrenches] Batt Cap AGM > Hello Wrenches, > > An owner of an existing system has a bank of twenty, 100 AH, 12 V Deep > cycle batteries of the Batcap > <http://www.xstaticbatcap.com/what-is-a-batcap-.html> > <http://www.xstaticbatcap.com/what-is-a-batcap-.html>brand. > > The bank is made up of four sets of 5 batteries in parallel to produce *500 > AH battery sets at 12 V.* These four parallel sets are then wired in > series to give a 48 V nominal bank. > > The battery voltages vary from around 13 to 15 volts. The bank is about 5 > years old. The CEO of Batcap told the system owner that these batteries > have lasted up to 30 years in solar applications, so he has high > expectations for these batteries being around for a while. > > My first impulse is to rewire the bank in a normal series - parallel > configuration. But there are too many strings to do this without a bus bar. > Besides, the batteries are likely damaged, and rewiring them might cause > the bank to exhibit unsuspected problems. How much money is worth putting > into this bank? $0? > > The owner seems like a reliable guy who likely hired the wrong installer. > He could use some help. What would you do in this situation? Rewire the > bank, leave it well enough alone or run for the hills. > > Thanks, > > Drake > > Drake Chamberlin > > > > > > *Athens Electric LLC OH License 44810 CO License 3773 NABCEP Certified > Solar PV 740-448-7328 *http://athens-electric.com/ > > ᐧ ᐧ
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