To clear up the point,
lead sulphate is very much more soluble in water than sulphuric acid,
and when batteries get flat all the sulphuric acid is reacted leaving
only water. That is why no current will flow when trying to charge them.
It is all well documented, see:
Vinal.G.W. (1945) Storage
Back to time related discussions please.
Thanks
Dave
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Neville,
Sorry, I don't agree. There is plenty of ion exchange
capability in the water left over from a totally dead
lead acid battery to corrode the skin off of your hands.
I have never found one where the specific gravity of the
water reached 1.0. Even a couple of drops of acid in
the water
Ever use batteries to back up your time toys David?
I would bet they were lead acid. More that a few
folks on this group are using lead acid to run such
things. Discussions of charging, discharging, and
care of batteries is just as apropos, in my opinion,
as discussions on which coax to use,
. A treasure trove of information.
Regards, John K1AE
Sent: Monday, July 28, 2014 8:39 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT Gel Cell question
Ever use batteries to back up your time toys David?
I would bet they were lead acid. More that a few folks
Hi:
Using lead acid batteries and a precision frequency standard is not a good
thing if they are too close together.
A number of decades ago (before the Time Nuts or the internet) I was able to purchase a rack mount Gibbs 5 MHz double
oven frequency standard that used a very nice Bliley glass
On 7/28/2014 1:12 AM, David C. Partridge wrote:
Back to time related discussions please.
Thanks
Dave
I worked on cesium standards (5071A)
at HP/Agilent with Len Cutler of flying clock
fame. You better believe that batteries are
time related. We jumped through all sorts of
hoops to get the
As I understand it, the only time that any sealed lead acid battery will
vent is in the case of gross overcharging. The battery is designed so
that normal charge rates and correct float voltage will result in
recombination of any hydrogen and oxygen produced. Was there a fault in
the
as long as it is not a gals/ceramic seal, there is no way to stop
sulfuric acid to get out from the cell, just imagine the dilatation
diffrence between plastic and metal...
73
Alex
On 7/28/2014 10:12 AM, Ed Palmer wrote:
As I understand it, the only time that any sealed lead acid battery
will
That said, I have never seen a gel cell, or a glass mat lead acid battery
leak acid, or emit fumes. I'm not saying it can't happen, just that in
all of my battery work, I haven't seen it... [unlike with nicads, where I
think something is wrong when I don't see leakage.]
The seal is something
I think we crossed some wires here. Pun intended.
Brook said the fumes ate away the traces and he is right. On a flooded cell
batteries such as he describes the fumes are nasty. Its quite normal on a
flooded cell to purposely drive them into overcharge. This is known as
equalizing. I have to do
Hi Ed:
I don't know. When I got the unit the batteries had been removed. The power supply consists of two 723 based voltage
regulator curcuits the first to drop the line voltage to about 20 V (float charging 3 each 6 V Gell Cells) and the
second 723 circuit to take in battery voltage and
Clearly under an abused situation I have seen cracked/fractured gel cells
as an example. Due to I speculate pretty much the poorest of charge design.
This includes powdery stuff, corrosion and metal that has been etched from
what at sometime was a liquid.
Almost the first thing I check is the
Hi Charles:
It turns out that Made in China does not in and of itself mean inferior.
There's a spectrum of quality levels.
For example there are some very high end companies in China and during working shifts they turn out products that are
very bit as good as any you would find.
But there
Paul wrote:
Stay away from hamfest/flea market batteries. They are almost always
bad and nothing really revives them. Pay the money and make sure you
get a recent build date.
Also, know that there is a huge range of quality represented by the
batteries available on the market.
In my previous work I was developing UPSs: I can confirm that in the last
years the quality of the typical gel batteries has declined.
What once was 7Ah batteries now are sold as 9Ah ones!
And 5-6Ah ones are sold as 7Ah... :(
One of the best way to identify the quality of sealed batteries is to
Elio
Oh man I have seen the amp hour magic also.
Thought maybe I was just getting older batteries. We have major home chains
in the US that batteries sit around for quite some time as measured by the
dust on them. So I was thinking that was the case.
Regards
Paul.
On Mon, Jul 28, 2014 at 6:50
in the RF/Telecom World.
-Brian, WA1ZMS
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: Monday, July 28, 2014 8:17 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT Gel Cell question
Brooke wrote:
It turns out that Made in China does not in and of itself mean inferior.
I did not say that it did -- please actually read what you are
replying to. Here is what I said:
These manufacturers are capable of designing and constructing
first-quality products, but the batteries
World.
-Brian, WA1ZMS
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of paul swed
Sent: Monday, July 28, 2014 8:17 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] OT Gel Cell question
Elio
Oh man I have
Anyone know why Gel Cell batteries go HI-Z if discharged below a certain level?
Also is there a way to rejuvenate a dead one?
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office
908-902-3831 cell
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Robert Roehrig
Sent: Sunday, July 27, 2014 12:52 PM
To: time-nuts@febo.com
Subject: [time-nuts] OT Gel Cell question
Anyone know why Gel Cell batteries go HI-Z
I think the PbSO4 forms crystals rather then spongy deposits that can
re-disolve on the lead plates and reduces the effective surface are of
the plate. Lower effective area means higher internal resistance.
With any lead acid battery the number of charge/dischage cycles
depends on how far you
Basically, it is a matter of thickness, and the quality of an insulator.
All lead acid cells work essentially the same: A lead oxide electrode
immersed in sulfuric acid converts to lead sulfate when power is drawn from
the cell. Lead sulfate is a very good insulator when it gets thick enough.
Hi Robert:
I've spent a lot of time charging batteries using different methods and on
various chemistries.
When the charge is in the form of a pulse, ideally including a reverse polarity
pulse, the charge is more effective.
This is also a way to sometimes, but not always, will recover a
27, 2014 3:41 PM
Subject: Re: [time-nuts] OT Gel Cell question
Robert wrote:
Anyone know why Gel Cell batteries go HI-Z if discharged below a certain
level?
Also is there a way to rejuvenate a dead one?
As others have explained, the problem is sulfation. I have had good
results de
Robert wrote:
Anyone know why Gel Cell batteries go HI-Z if discharged below a
certain level?
Also is there a way to rejuvenate a dead one?
As others have explained, the problem is sulfation. I have had good
results de-sulfating lead-acid batteries of all types (flooded, gel,
AGM) with
At 04:09 PM 7/27/2014, Tom Miller wrote:
If the battery is more than five years old it is most likely time to trade it
in for a new one.
I have used uninterruptable power supplies and standby power supplies for
decades at work to keep mission-critical hardware online. I concur fully with
Tom
I too have spent a lot of time charging batteries using different methods on
various chemistries. Once upon a time, I build a number of suitcase battery
chargers for the US Army that allowed them to charge every portable secondary
battery type that they had in inventory... SLA, AgO, NiCD, NIMH,
it is not a high performance battery but extremely robust, see there
http://www.nickel-iron-battery.com/
it is no polluting, it could be shorted out overcharged
if you are lucky and find one old forklift with Edison Battery -- which
was built some fifty years egoit will out last you too
you
Hi,
Lead acid cells have lead supports carrying lead oxide and lead metal active
material
in an electrolyte of sulphuric acid.
When they discharge, the sulphuric acid electrolyte is reacted with the oxides
and metal
to form lead sulphate and the concentration of the acid falls, that is why
...@febo.com
[mailto:time-nuts-boun...@febo.com] On Behalf Of Alex Pummer
Sent: Sunday, July 27, 2014 15:48
To: time-nuts@febo.com
Subject: Re: [time-nuts] OT Gel Cell question
it is not a high performance battery but extremely robust, see there
http://www.nickel-iron-battery.com
A small disagreement on a couple of points
Lead sulfate does not dissolve (in the normal battery chemistry),
and does not go all over the place. It forms at the lead and the
lead oxide plates, during discharge, and there it stays
(unless it breaks off) until you charge the cell. It is the
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