If the 180 watt panel will provide enough current to run the recovery
process, then give it a try. What I expect is that your current will
vary throughout the day. Not sure if this is a critical point or if it
will just prolong the process. Pay attention to the temperature. I use
a laser temp probe on the terminals every 30 minutes to verify.
Another thing to monitor is the current. It will probably start very
low and build over time due to high resistance from sulfated plates.
During this time the voltage might get really high and then lower
some. Don't worry about the voltage. After a while the current will
begin to drop. This means the recovery process is working.
I just realized that this battery bank must be 4 in series and ten
parallel strings. This is a horrible design that can never work right
without extensive monthly maintenance. The strings with higher
resistance will not be charged properly. Because of this, many strings
will be undercharged every day. EVERY day! So even if you recover
these batteries, someone will need to test and equalize at least every
month. I really want to stress this point as multiple parallel
batteries are the ruin and waste of many thousands of tons of
batteries each year. I never design for more than two strings in
parallel. Do this and be happy.
Larry Crutcher
www.starlightsolar.com
[email protected]
(928) 941-1660
Retail Store & Shipping
2998 Shari Ave.
Yuma, AZ 85365
Mailing address
11881 South Fortuna Road; #210
Yuma, AZ 85367
Renewable Energy Systems Sales, Service, Installations
On Dec 1, 2009, at 6:00 AM, Conrad Geyser wrote:
Thanks for the amazing responses everyone!
Larry, it sound as though the parameters below are a perfect match
for your average ~180 watt PV module in December sunlight wired back
through a diode to a test battery inside? Does it matter if the
process get’s interrupted by a few nights / cloudy days? Do you
have a preferred test approach?
Yeah, this bank represents a huge amount of resources; I want to
make sure it can’t be saved.
Conrad
Cotuit Solar
From: [email protected] [mailto:[email protected]
] On Behalf Of Larry Crutcher, Starlight Solar
Sent: Monday, November 30, 2009 11:17 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] concord batteries, EQUALIZE Them!
Conrad,
We have sold many Concord (Lifeline, Sun Xtender...) batteries over
the years. They are the best and half of our battery sales are Deka
and Concord AGM's.
When our mobile customers abuse their AGM batteries, I use an
equalization process that has a constant current and no voltage
limit to restore them. I am sure you have heard that you should
never equalize an AMG battery. This is not true but the process must
be tightly controlled. I have done it many times and the result is
always to recover some or most capacity.
Do one battery at a time.
1. Battery temp: 77 degrees (+/-5) and stable
2. Apply charge current limited to 5% of the 20hr rate. eg. 220 AH
will be 11 amps. Do not regulate voltage!
3. Monitor temperature and voltage.
4(a) If temperature reaches 130F, stop the process. Start again when
the battery temperature has been lowered to room temperature.
4(b) When voltage reaches 2.6 vpc, continue charging for 4 hours.
Voltage may reach 3 vpc!! Follow 4(a) about temp.
5. After this process, perform a capacity test.
This has worked for me with chronically undercharged AGM's of all
types. I have never had one vent or go into thermal run away. At
the price of these batteries, it is worth the time to try if you
have the power source and time.
For reference this process is outlined in the Lifeline Technical
manual, page 20. http://www.lifelinebatteries.com/manual.pdf
Larry Crutcher
www.starlightsolar.com
[email protected]
(928) 941-1660
On Nov 29, 2009, at 6:48 PM, Conrad Geyser wrote:
In the vein of us on grid folks who’s heads spin when the off grid
folks start talking about charge programming and gen set start up
parameters…
I am servicing an orphaned 48 V off grid system that is only 1 1/2
years old, with 40 Concorde Sun Extender batteries, which are for
the most part, shot (about half of them under 10V after a generator
EQ charge). I’m sure the batteries have been abused at least after
the point that someone lowered the generator start voltage to 40V.
We’re still doing fact finding on the charge parameters for the PV
and wind, but I’m wondering if there is anyone that has an opinion
on the Concorde batteries.
And at least at this point, I’m glad I had to study for some off
grid questions on the NABCEP test, not to mention the conversations
on this list. : >
Conrad
Cotuit Solar
From: [email protected] [mailto:[email protected]
] On Behalf Of Bob-O Schultze
Sent: Wednesday, November 25, 2009 9:59 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] Nabcep - grid tie---Off grid
William,
Nice to meet you -however briefly- at the Solar Zoo in Anaheim.
If you don't see the value in being NABCEP certified, then you
shouldn't bother with it. If your state- as more than a few have-
decides to recognize it in some way that affects your pocket, then
you'll likely change your mind PDQ. I've personally gotten one or
two jobs that I know about because I was Certified and the other
bidder was not, but our bids were very close in price. Low-ballers,
like head lice, are just a nasty fact of life.
While I generally agree with you on your point #2, it varies a lot
state to state. I'm licensed in CA and OR. While I understand the
rules in CA are changing, enforcement is, and has always been, a
joke. In OR, you need a 4000 hour apprenticeship AND 256 hours of
general electrical classroom time to get a Renewable Energy license.
A general journeyman license is twice that. I've had inspectors come
to our job site and check that everyone is licensed. In OR, you
don't lay hands on a wire without a license. Ever hear of the like
in CA? Maybe in the big cities, but nowhere else.
We're totally on the same page about the IBEW. If you understand
that their goal is total domination of the electrical trade
everywhere, a lot of how they operate makes sense. I'm a pro-Union
kinda guy as a rule, but, like religion, too much of a thing is way
worse than none.
As to experience with EMT and the like, again it varies state to
state and certainly region to region. In this neck of the woods, if
you can't bend an offset or saddle bend, you are either a new
apprentice or unemployed.
Best, Bob-O
On Nov 24, 2009, at 11:48 PM, William Miller wrote:
Friends:
I'd like to make two brief points on the training/NABCEP debate:
1. If I thought NABCEP certification would get me one more job I'd
normally lose to a low-ball bidder, I'd be inclined to sit for the
test, but it won't.
2. Most solar electric installers could not be considered
electricians. Until they learn the trade, they are not qualified to
install the most basic grid tie system. Conversely, many
electricians with the most basic electrical skills think they know
all that needs to be known to design and install solar-electric.
Wrong again.
I don't support the IBEW concept of taking over the solar industry
by force, but I do respect their concept of actually encouraging
well rounded electrician's skills. How many solar installers can
actually lay an offset into a stick of EMT? Not many. Most are
glorified stereo installers, plugging and praying.
Respectfully,
William Miller
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