Congratulations on that - even more impressed that somebodycan stay awake all
that time!
Regards,
Bill Coleman C&C 39
-------- Original message --------
From: Michael Brown via CnC-List <cnc-list@cnc-list.com>
Date: 7/21/17 09:52 (GMT-05:00)
To: cnc-list@cnc-list.com
Cc: Michael Brown <m...@tkg.ca>
Subject: Re: Stus-List Voltages
We have a number of UPSes in our customer base we support. I have recycled
at least 60 AGM batteries this year and sometimes play with them to see if they
are good or can be recovered.
Even fairly flat batteries may recover. If they can be charged back up, and I
use
a constant current power supply instead of a battery charger, I see how long the
charge takes. Having a 100 amp hour battery come to full charge after 10 hours
at 1 amp means it isn't chemically taking a charge.
After the battery has been charged, and that may take days, I put a light load
on
it to remove a small amount of AH, say 10%. The battery is left to sit for a
week
or so and then I measure the voltage. What I am looking for is one or more cells
that are self discharging. If the battery settles in at around 12+ volts there
is
hope, but if it shows 10 ( or 8 ) then a cell has gone.
I can put the batteries back into a Smart UPS and do a run down load test,
basically the UPS switches to battery and runs it down to some voltage,
switches back to AC and then sends me a report. That will tell me how much
capacity the battery has in it.
A lot of the time one battery out of the set has gone, some UPSes have
10 batteries in series, some up to 14 in parallel and series. If the UPS is
only 2 - 3 years old I may find only one completely bad battery, and maybe
three that recover. They are not new, may have 80%+ of original capacity
but can be reused in a less critical application.
So charge them up, let them sit and check for around 12 volts. If that is
good do a run down test ( the old 12v camper bulbs are great for this )
and see what capacity is left.
Michael Brown
Windburn
C&C 30-1
PS: I finished the Lake Ontario 300 last weekend ( and Monday ). Finish times
ranged from 45 to 61 hours, a result of the wind dying on Monday. Windburn
took first in division, first in fleet and line honours on the Scotch Bonnet
course.
These C&Cs keep going and going.
Date: Fri, 21 Jul 2017 13:11:30 +0000
From: "Della Barba, Joe" <joe.della.ba...@ssa.gov>
It is not absolutely 100% the batteries are done for. 99% maybe, but sometimes
wet cells, especially traction batteries, can take a good equalizing charge and
come back to life with some capacity left.
My old extra car had a short that would run the battery stone cold dead. It
survived about 3 of these and still could be used as a start battery, but it
had almost no reserve.
Joe
Coquina
From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of RANDY via
CnC-List
Sent: Thursday, July 20, 2017 7:24 PM
Well, if I learned an expensive lesson, I'll just have to accept that. I
checked all the cells before putting the charger on them, and they were full.
After charging they are still full (even though I heard the liquid bubbling
i.e. creating and venting gas toward the end of the charging period).
The one battery I put back on the boat yesterday was able to start my A4 and
run my electrical stuff no problem, just like normal before all this. I'll
take the other down to the boat tomorrow and measure its voltage with my
multimeter- it will have been at rest, disconnected, for 24+ hours by then.
But I know there is a difference between instantaneous voltage and amp-hour
capacity. These are deep-cycle batteries, and I cycled them very deeply :)
I'll just have to monitor the situation for the rest of the season and see how
bad my mistakes are going to hurt :)
Cheers,
Randy
From: "Fred Hazzard via CnC-List"
<cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>>
Sent: Thursday, July 20, 2017 3:27:38 PM
I can tell you from personal experience that AGMs won't servive either. I had
4 hooked in parallel that I flattened to 4.5 v . A painful experience. At the
same time I lost my inverter charger.
Fred Hazzard
S/V Fury
C&C 44
Portland, Or
On Jul 20, 2017 12:34 PM, "Bill Bina - gmail via CnC-List"
<cnc-list@cnc-list.com<mailto:cnc-list@cnc-list.com>> wrote:
I'm sorry to be the bearer of bad news, but if those voltages of 4.7 volts and
5.7 volts were correct, they mean these batteries have been quite severely
damaged and will never have anywhere near full capacity again. That is not a
maybe. You can get many batteries like that to take a surface charge and appear
okay with a voltage reading that looks somewhat normal. There is no muscle
behind it. The charger is telling you they are 100% charged to their new and
very diminished capacity. Some of the cells may also have run dry. This was
not survivable for any flooded battery regardless of quality, or how it was
treated otherwise.
Bill Bina
On 7/20/2017 10:10 AM, RANDY via CnC-List wrote:
An update on this. Monday morning I brought my batteries home (I've got two of
these:
https://www.walmart.com/ip/EverStart-Maxx-Marine-Battery-Group-Size-29DC/20531539
dated May/June 2014 with relatively light use and constantly maintained by a
3amp solar charger). And I bought this inexpensive charging unit:
https://www.walmart.com/ip/Schumacher-Electric-15-Amp-Battery-Charger/46167057.
One battery measured 4.7v before charging, and the other 5.7v, according to the
charger's test function. Each battery was on the charger for about 33 hours to
charge back up to 13.2v / 13.5v and 100% charge according to the charger. I
haven't measured their voltage independently after charging with a multi-meter,
but I did that at the start of the season and they were healthy.
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