Quiz question

On Fri, 11 Oct 2013 17:54:39 +0100, "Dave Plowman (News)"
wrote:

In article ,
Max Demian wrote:
What I want to know is, what *exactly* have they done to car batteries
so that they don't need to be topped up any more. I know that they are
supposed to use a different lead alloy for the electrodes, which
supposedly reduces the amount of 'gassing' (conversion of water to
hydrogen and oxygen by electrolysis) during charging, but what about
loss by evaporation?

The physical design of the battery is designed to 'condense' things back
into the cell.

Also alternator regulators are better designed to prevent over-charging.

Alternator regulators were 'better designed' more or less from day
one of their introduction when compact silicon rectifier diodes of
sufficient current rating became available (late 60s, early 70s ?) to
make the alternator a commercially viable replacement for the dynamo
and its associated electromechanical regulator/cut out control box
that had been the only viable means of supplying electrical power up
until that point.

The vibrating relay voltage regulator left a lot to be desired with
regard to stability and accuracy. The optimum voltage setting for a 12
volt system being adjusted for a nominal 15 volts with a plus or minus
1 volt variation.

The only saving grace being that the cells could be readily topped up
to compensate for the relatively high amount of 'gassing' this
involved. Since automobile drivers had, out of necessity, to be
considerably more hardy and resourceful than today's current crop of
lazy retards engendered by the automobile industry's pandering to the
whims and aspirational desires of successive generations of "Tech
Challenged' drivers, this need for regular maintainance of the battery
wasn't deemed to be a particularly onerous task (nor out of place in a
regimen of other week by week maintainance chores entrusted to the
care of the proud owner/driver).

Although the introduction of alternators made such maintainance free
battery types a viable proposition, their extra expense couldn't
really be justified until the need for the owner to lift the bonnet up
on a weekly maintainance schedule for the sake of other vital
maintaince checks had disappeared leaving only the battery as the one
remaining item being in need of such frequent checks.

Then, and only then, did the idea of a maintainance free battery
start to look like an attractive luxury feature that was worthy of the
extra expense in the eye of the motoring public which led to an
increase in market demand allowing the battery manufacturers to
develop less pricier versions of maintainance free battery types.
There's still a price premium but it's not as great as it used to be
when they they were first introduced onto the market.
--
Regards, J B Good

On Fri, 11 Oct 2013 23:54:25 +0100, "Dave Plowman (News)"
wrote:

In article ,
Roderick Stewart wrote:
We used a lot of smaller nicad batteries that clipped onto the backs
of cameras, or fitted into video recorders and sound mixing desks,
either 1.6Ah or 3.5Ah. These deteriorated after a year or so, but what
affected them most was cold weather. On a winter's day some of them
only lasted about half as long as they should. They also cost a
fortune; a Sony or PAG 3.5Ah nicad battery would cost about £200,
whereas a biggish car battery of about 60Ah would cost about a quarter
of that, and didn't suffer so much in the cold. We tended to use car
batteries or Dryfits in homebrew carry cases except where portability
was an issue, because although they were heavy we didn't have to
change them so often.

Yes. If size weight and portability wasn't a major issue, car batteries
were a very cost effective solution - provided you didn't run them flat.
Use them down to no more than half capacity, and they seemed to last as
well as in a car.

The major problem is that car batteries don't take kindly to
continuous float charging of the type used by most UPSes (normally
13.8v per 6 cell battery's worth) unlike the SLA types which will
quite happilly thrive under this regime.

Purpose designed car battery charger/conditioners maintain the charge
state by allowing the battery voltage to decay after the initial bulk
charge phase by a small amount before topping them up with a short
burst of relativley high charging current to bring the voltage up to
something like 14.2 to 14.5 volts before allowing them to settle back
down over the next few days before the next topping up charge is
applied.
--
Regards, J B Good

In article ,
Johny B Good wrote:
It is in a fully charged state chemically speaking but with the acid
removed. Add acid of the correct SG, and you have a battery ready to
go after an hour or so 'settling'. It's also a safe way to transport
a battery with the acid in a separate sealed container - that's how
most mail order batteries arrive.

I think you meant to say: "that's how most mail order Flooded Cell
Lead Acid batteries arrive.

No I didn't. Not in the context of talking about dry charged lead acid.
The principle doesn't exist with SLA types.

Well, a dry charged lead acid battery (or cell) is simply a Flooded
Cell Lead Acid type that has simply had the electrolyte filling stage
of its manufacture postponed so that the end user can complete this
final stage of manufacture for himself.

Well yes. But I've never seen an SLA type (gel) offered in this condition.
Which means they are 'active' during storage before sale, which might mean
a shorter life.

And of course transporting a wet battery has the risk of it spilling as
it's not really possible to seal it effectively. So keeping the hazardous
acid in a separate sealed container makes sense.

--
*Do infants enjoy infancy as much as adults enjoy adultery?

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Johny B Good wrote:
Probably the same as anything else these days that is regarded as
"maintenance free". You just throw it away before it needs any.

Not so - I've just replaced an 11 year old battery which never had any
attention. Some years ago that would have been unthinkable.

That, quite obviously, must have been a genuine "Maintainance Free"
design with pressure relief vent caps and catalytic materials
incorporated into each cell to recycle the hydrogen/oxygen mix back
into water (and low grade heat).

Not sealed, it had the usual filler caps concealed below a cover. It has a
vent tube attached too. Just an ordinary Bosch Silver - hadn't much choice
due to the odd shape. Of course I've no idea about the internal
construction.

I bet you were taking full advanatage of an engine that could fire up
within one revolution of being cranked on the starter to minimse wear
and tear on both battery and starter motor. Some (most?) people will
keep the starter running for a second or so after the engine has
actually fired up which puts additional stress on battery and starter.

Yes it does start promptly. But cars in a good state of repair and tune
always have done, ever since I've been driving.

--
*Do infants enjoy infancy as much as adults enjoy adultery? *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Johny B Good wrote:
Also alternator regulators are better designed to prevent over-charging.

Alternator regulators were 'better designed' more or less from day
one of their introduction when compact silicon rectifier diodes of
sufficient current rating became available (late 60s, early 70s ?) to
make the alternator a commercially viable replacement for the dynamo
and its associated electromechanical regulator/cut out control box
that had been the only viable means of supplying electrical power up
until that point.

I've seen plenty of early alternators with badly designed regulators. Some
even adjustable.

--
*You're just jealous because the voices only talk to me *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Johny B Good wrote:
We used a lot of smaller nicad batteries that clipped onto the backs
of cameras, or fitted into video recorders and sound mixing desks,
either 1.6Ah or 3.5Ah. These deteriorated after a year or so, but what
affected them most was cold weather. On a winter's day some of them
only lasted about half as long as they should. They also cost a
fortune; a Sony or PAG 3.5Ah nicad battery would cost about £200,
whereas a biggish car battery of about 60Ah would cost about a quarter
of that, and didn't suffer so much in the cold. We tended to use car
batteries or Dryfits in homebrew carry cases except where portability
was an issue, because although they were heavy we didn't have to
change them so often.

Yes. If size weight and portability wasn't a major issue, car batteries
were a very cost effective solution - provided you didn't run them flat.
Use them down to no more than half capacity, and they seemed to last as
well as in a car.

The major problem is that car batteries don't take kindly to
continuous float charging of the type used by most UPSes (normally
13.8v per 6 cell battery's worth) unlike the SLA types which will
quite happilly thrive under this regime.

But if they're being used on location, they wouldn't be on charge. If
mains were available, you'd use that. And for anything which needs to be
battery powered on the move say the camera you'd use the correct battery.

I'm talking about powering up some form of base station or reasonably
static equipment.

--
*Nothing is foolproof to a sufficiently talented fool*

Dave Plowman London SW
To e-mail, change noise into sound.

On Fri, 11 Oct 2013 23:50:57 +0100, "Dave Plowman (News)"
wrote:

In article ,
Max Demian wrote:
I think I must have looked at that article befo Wikipedia would
usually be my first port of call. It seems to be rather
old-fashioned/generalised. I haven't seen a car battery with removeable
caps for years, and the ones I have looked at don't seem to be 'sealed'
in the sense of being able to be mounted in any orientation, and they
do appear to have liquid electrolyte, but just no way to top them up.

They usually have normal caps under some sticky back plastic. But simply
don't need topping up - unless you have a faulty alternator. Even on my 30
year old Rover.

This discussion reminds me of when I was in the RAF in the 1950s. There
was alleged to be a difference in the batteries used in bomber aircraft
and fighter aircraft. They were all said to be lead-acid batteries.
The explanation was that fighter batteries were designed to be used in
all positions including upside down.

The joke was that if a bomber was flown upside down the acid would pour
out of its batteries.

Obviously, fluid would not pour out of a battery just because it was
upside down, so I assume that the caps/bungs/seals on the bomber
batteries were not designed for frequent upside-down use with increased
g-force.

The Vulcan bomber which was very manoeuvrable and could perform like a
fighter plane was said to be equipped with fighter batteries.

--
Peter Duncanson
(in uk.tech.digital-tv)

In article ,
Peter Duncanson wrote:
On Fri, 11 Oct 2013 23:50:57 +0100, "Dave Plowman (News)"
wrote:

In article ,
Max Demian wrote:
I think I must have looked at that article befo Wikipedia would
usually be my first port of call. It seems to be rather
old-fashioned/generalised. I haven't seen a car battery with removeable
caps for years, and the ones I have looked at don't seem to be 'sealed'
in the sense of being able to be mounted in any orientation, and they
do appear to have liquid electrolyte, but just no way to top them up.

They usually have normal caps under some sticky back plastic. But simply
don't need topping up - unless you have a faulty alternator. Even on my 30
year old Rover.

This discussion reminds me of when I was in the RAF in the 1950s. There
was alleged to be a difference in the batteries used in bomber aircraft
and fighter aircraft. They were all said to be lead-acid batteries.
The explanation was that fighter batteries were designed to be used in
all positions including upside down.

The joke was that if a bomber was flown upside down the acid would pour
out of its batteries.

Obviously, fluid would not pour out of a battery just because it was
upside down, so I assume that the caps/bungs/seals on the bomber
batteries were not designed for frequent upside-down use with increased
g-force.

The Vulcan bomber which was very manoeuvrable and could perform like a
fighter plane was said to be equipped with fighter batteries.


However, at that time batteries used in planes were totally sealed NiFe
ones.

--
From KT24

Using a RISC OS computer running v5.18

On Sat, 12 Oct 2013 12:34:34 +0100, Peter Duncanson
wrote:

On Fri, 11 Oct 2013 23:50:57 +0100, "Dave Plowman (News)"
wrote:

In article ,
Max Demian wrote:
I think I must have looked at that article befo Wikipedia would
usually be my first port of call. It seems to be rather
old-fashioned/generalised. I haven't seen a car battery with removeable
caps for years, and the ones I have looked at don't seem to be 'sealed'
in the sense of being able to be mounted in any orientation, and they
do appear to have liquid electrolyte, but just no way to top them up.

They usually have normal caps under some sticky back plastic. But simply
don't need topping up - unless you have a faulty alternator. Even on my 30
year old Rover.

This discussion reminds me of when I was in the RAF in the 1950s. There
was alleged to be a difference in the batteries used in bomber aircraft
and fighter aircraft. They were all said to be lead-acid batteries.
The explanation was that fighter batteries were designed to be used in
all positions including upside down.

The joke was that if a bomber was flown upside down the acid would pour
out of its batteries.

Obviously, fluid would not pour out of a battery just because it was
upside down, so I assume that the caps/bungs/seals on the bomber
batteries were not designed for frequent upside-down use with increased
g-force.

The Vulcan bomber which was very manoeuvrable and could perform like a
fighter plane was said to be equipped with fighter batteries.

There was a simple mechanical modification to the flooded cell type
battery which would make them "Spill Proof" for most practical
purposes. The trick was basically to enlarge the space above the
plates to accomodate specially modified vented filler caps to be used
which had an extended tube that could act as a coffer dam in the event
of total inversion (the extra volume also allowed the electrolyte
level to remain below the tubular extension in all other orientations
as well).

However, unlike the modern SLA types, their performance would be
completely compromised when totally inverted and partially so for
lesse departures from upright. The design function was primarily to
avoid electrolyte loss and consequencial damage from an acid spill due
to handling mishaps.

I think there was a a varient of this principal based on the use of a
weighty ball valve built into the vent caps (sort of opposite to the
use of a boyant ball in a snorkelling tube) so that during rotations
just in excess of 90 degrees from perfectly upright wrt to the
gravitational field, the ball would press against an O ring and
totally seal the cell.

This was fine for short (transient) periods of inverted operation and
only slightly compromised the cell's performance since the plates
never had to suffer complete electrolyte deprivation (provided the
electrolyte level was properly maintained).
--
Regards, J B Good

On Sat, 12 Oct 2013 12:49:31 +0100, charles
wrote:

In article ,
Peter Duncanson wrote:
On Fri, 11 Oct 2013 23:50:57 +0100, "Dave Plowman (News)"
wrote:

In article ,
Max Demian wrote:
I think I must have looked at that article befo Wikipedia would
usually be my first port of call. It seems to be rather
old-fashioned/generalised. I haven't seen a car battery with removeable
caps for years, and the ones I have looked at don't seem to be 'sealed'
in the sense of being able to be mounted in any orientation, and they
do appear to have liquid electrolyte, but just no way to top them up.

They usually have normal caps under some sticky back plastic. But simply
don't need topping up - unless you have a faulty alternator. Even on my 30
year old Rover.

This discussion reminds me of when I was in the RAF in the 1950s. There
was alleged to be a difference in the batteries used in bomber aircraft
and fighter aircraft. They were all said to be lead-acid batteries.
The explanation was that fighter batteries were designed to be used in
all positions including upside down.

The joke was that if a bomber was flown upside down the acid would pour
out of its batteries.

Obviously, fluid would not pour out of a battery just because it was
upside down, so I assume that the caps/bungs/seals on the bomber
batteries were not designed for frequent upside-down use with increased
g-force.

The Vulcan bomber which was very manoeuvrable and could perform like a
fighter plane was said to be equipped with fighter batteries.


However, at that time batteries used in planes were totally sealed NiFe
ones.

That wouldn't suprise me. The story and related joke about acid pouring
out of batteries may have been decades old.

--
Peter Duncanson
(in uk.tech.digital-tv)