I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Only 'smart' bit was that it had a 'display pcb of 3 LED's .... one for
power, the other 2 just via a zener diode to measure aprox charge
voltage - no actual control at all.


Thought as the case, transformer, diodes & heatsinks are fine ... could
use this a basis for a proper 3 stage 'SMART Charger'

I have couple of links to full designs, but these use PICs and need
programming, which I do not have facility to do.
There are really SMART and fully programmable for battery parameters
etc. and Deep Cycles batteries .... eg

http://www.swinburne.edu.my/docs/lib...200701_jan.pdf

overkill for my needs ... which is basic low speed charge & float charge.
Anybody know of a simpler circuit ... all I need is ability to charge 6
& 12 V batteries, non-deep cycle.

Rick Hughes explained :
overkill for my needs ... which is basic low speed charge & float charge.
Anybody know of a simpler circuit ... all I need is ability to charge 6 & 12
V batteries, non-deep cycle.

Depending on the current output level of the charger...

Look up a circuit for a 2N3055 (which is a high current transistor)
using a 1amp 5v regulator with a pot on the control pin to set the
output voltage. Add an extra pot and a couple of switches and you
should then be able to get a charge voltage and a float charge voltage
from it.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On 28 Dec, 21:05, Rick Hughes
wrote:
I have a relatively new Car Battery Charger *(twas a gift) * claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Only 'smart' bit was that it had a 'display pcb of 3 LED's .... one for
power, the other 2 just via a zener diode to measure aprox charge
voltage - no actual control at all.

Thought as the case, transformer, diodes & heatsinks are fine ... could
use this a basis for a proper 3 stage 'SMART Charger'

I have couple of links to full designs, but these use PICs and need
programming, which I do not have facility to do.
There are really SMART and fully programmable for battery parameters
etc. * and Deep Cycles batteries .... * eg

http://www.swinburne.edu.my/docs/lib...200701_jan.pdf

overkill for my needs ... which is basic low speed charge & float charge.
Anybody know of a simpler circuit ... all I need is ability to charge 6
& 12 V *batteries, non-deep cycle.


I'd be very interested to learn from where it was bought, if it's not
to much trouble.

In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Then it will blow up when you try and use it.

--
*Re-elect nobody

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

On 28/12/2012 22:20, Mr Fuxit wrote:
On 28 Dec, 21:05, Rick Hughes
wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Only 'smart' bit was that it had a 'display pcb of 3 LED's .... one for
power, the other 2 just via a zener diode to measure aprox charge
voltage - no actual control at all.

Thought as the case, transformer, diodes & heatsinks are fine ... could
use this a basis for a proper 3 stage 'SMART Charger'

I have couple of links to full designs, but these use PICs and need
programming, which I do not have facility to do.
There are really SMART and fully programmable for battery parameters
etc. and Deep Cycles batteries .... eg

http://www.swinburne.edu.my/docs/lib...200701_jan.pdf

overkill for my needs ... which is basic low speed charge & float charge.
Anybody know of a simpler circuit ... all I need is ability to charge 6
& 12 V batteries, non-deep cycle.


I'd be very interested to learn from where it was bought, if it's not
to much trouble.

Halfords .... its an ABSAAR BBL range Type 3 model 1205

High/Low charge rate 12V only

On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output
to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
............ why would it blow up ?

Rick Hughes wrote:

Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output
to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Dave's speciality is the prognostication of doom. He was a Mayan in a
previous life.

Bill

In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output
to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

--
*Why is it that doctors call what they do "practice"?

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

Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.
Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output
to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

--
Tciao for Now!

John.

In message , "Dave Plowman (News)"
writes
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output
to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Could the transformer be designed to operate inefficiently; with the
output voltage drooping to limit the current? Inadequate turns or air
gap in the iron circuit?


--
Tim Lamb

In message , John Williamson
writes
Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.
Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC
output to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?
Because a lead acid battery has a very low internal resistance. To a
power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

Snap:-)


--
Tim Lamb

On 29/12/12 16:02, John Williamson wrote:
Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift)
claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.
Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC
output to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a
power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

Or in older times a nasty copper oxide rectifier with a massive forward
impedance.


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

In article ,
John Williamson wrote:
Because a lead acid battery has a very low internal resistance. To a
power supply like that virtually a dead short. A crude charger would
have some form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

You mean use a thin enough wire in the winding so that acts as the
resistance? Doesn't sound like a recipe for decent life.

--
*A cartoonist was found dead in his home. Details are sketchy.*

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

In article ,
The Natural Philosopher wrote:
Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

Or in older times a nasty copper oxide rectifier with a massive forward
impedance.

Oldest charger I've got - '50s - still has a resistor. Or rather a couple
so you can set the charge rate. Approximately.

--
*If at first you don't succeed, redefine success.

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

Dave Plowman (News) wrote:
In article ,
John Williamson wrote:
Because a lead acid battery has a very low internal resistance. To a
power supply like that virtually a dead short. A crude charger would
have some form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

You mean use a thin enough wire in the winding so that acts as the
resistance? Doesn't sound like a recipe for decent life.

As has been mentioned, air gap in the core, a low reluctance core, or
just fiddling with the inductances, all of which work as wattless
droppers, more or less. Transformer designers don't *have* to go for low
impedances all round.

They can also go for low efficiency and cheap, in which case people
don't expect them to last long, and as long as they insert overheating
protection such as a fusible element, they're safe.

--
Tciao for Now!

John.

John Williamson expressed precisely :
Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.
Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output to
a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a sagging
output with increasing load. Saves the regulator and means the transformer's
cheaper, too.

Is the correct answer.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On 29/12/2012 16:02, John Williamson wrote:
Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift)
claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.
Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC
output to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a
power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Unless they've cunningly used the transformer's impedance to give a
sagging output with increasing load. Saves the regulator and means the
transformer's cheaper, too.

No in-line resistor
Only resistors are around the LED's and are typical low current items.

My previous charger was the same .... transformer rectifier output.

I increased its performance by putting large value capacitor on output
.... raised o/p voltage sufficient to make charging more effective ....
no good for float charge though.

On 29/12/2012 16:07, Tim Lamb wrote:
In message , "Dave Plowman (News)"
writes
In article ,
Rick Hughes wrote:
On 29/12/2012 00:11, Dave Plowman (News) wrote:
In article ,
Rick Hughes wrote:
I have a relatively new Car Battery Charger (twas a gift)
claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Then it will blow up when you try and use it.

Why ?

220V AC step down transformer full wave rectifier giving DC output
to a pair of croc clip ended leads ..

Display gives some LED indication, and there is an in-line fuse
........... why would it blow up ?

Because a lead acid battery has a very low internal resistance. To a
power
supply like that virtually a dead short. A crude charger would have some
form of series resistance to limit the maximum current.

Could the transformer be designed to operate inefficiently; with the
output voltage drooping to limit the current? Inadequate turns or air
gap in the iron circuit?




all good stuff guys .... but back to original Q ... anyone got a 3 stage
charger circuit ?

On Sat, 29 Dec 2012 21:20:35 +0000, Rick Hughes wrote:

all good stuff guys .... but back to original Q ... anyone got a 3
stage charger circuit ?

Why bother, wander along to Aldi and pick up one of their 6/12 V battery
chargers for less than 15 squid...

Though ISTR some mention of SLA gell battery rather than a wet cell type.
These are rather more fussy about charging but these days I'd expect to
find a chip that does multi stage charging for SLA's. How else can you
buy one for a tenner?

--
Cheers
Dave.

In article ,
Rick Hughes writes:
On 28/12/2012 22:20, Mr Fuxit wrote:
On 28 Dec, 21:05, Rick Hughes
wrote:
I have a relatively new Car Battery Charger (twas a gift) claimed to
be electronic 'smart' charger.
Took the cover off and found it to be a straight transformer to full
wave rectifier set of diodes ... and out to croc leads.

Only 'smart' bit was that it had a 'display pcb of 3 LED's .... one for
power, the other 2 just via a zener diode to measure aprox charge
voltage - no actual control at all.

Thought as the case, transformer, diodes & heatsinks are fine ... could
use this a basis for a proper 3 stage 'SMART Charger'

I have couple of links to full designs, but these use PICs and need
programming, which I do not have facility to do.
There are really SMART and fully programmable for battery parameters
etc. and Deep Cycles batteries .... eg

http://www.swinburne.edu.my/docs/lib...200701_jan.pdf

overkill for my needs ... which is basic low speed charge & float charge.
Anybody know of a simpler circuit ... all I need is ability to charge 6
& 12 V batteries, non-deep cycle.


I'd be very interested to learn from where it was bought, if it's not
to much trouble.

Halfords .... its an ABSAAR BBL range Type 3 model 1205

High/Low charge rate 12V only

I picked up one in halfords, and I could see through the vent grill
that there was just a transformer and rectifier in it. It was much
more expensive than the Aldi intelligent switched mode one, which is
going to be very much better.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
I picked up one in halfords, and I could see through the vent grill
that there was just a transformer and rectifier in it. It was much
more expensive than the Aldi intelligent switched mode one, which is
going to be very much better.

I bought quite a few of those Lidl chargers when they came out as Xmas
presents, so maybe 5 years ago. At least two have failed, including one of
mine.
So I'd say ok for occasional use, but I'm not sure how well they'd last
long term.

--
*Why do they put Braille on the drive-through bank machines?

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

On 30/12/2012 10:58, Andrew Gabriel wrote:
In article ,
Rick Hughes writes:

I picked up one in halfords, and I could see through the vent grill
that there was just a transformer and rectifier in it. It was much
more expensive than the Aldi intelligent switched mode one, which is
going to be very much better.



Only reason I have it as it was a gift .... neighbour borrowed my
charger and lost it ... an felt he had to replace it.

On 30/12/2012 00:19, Dave Liquorice wrote:
On Sat, 29 Dec 2012 21:20:35 +0000, Rick Hughes wrote:

all good stuff guys .... but back to original Q ... anyone got a 3
stage charger circuit ?

Why bother, wander along to Aldi and pick up one of their 6/12 V battery
chargers for less than 15 squid...

Though ISTR some mention of SLA gell battery rather than a wet cell type.
These are rather more fussy about charging but these days I'd expect to
find a chip that does multi stage charging for SLA's. How else can you
buy one for a tenner?

but are they any better ... do they give genuine 3 stage charging.

want to end up with correct float condition.

On Friday, December 28, 2012 9:05:27 PM UTC, Rick Hughes wrote... Anybody know of a simpler circuit ... all I need is ability to charge 6 & 12 V batteries, non-deep cycle.

Similar prob:? --2 year illness meant no charging of two gardening strimmer and cutter batteries. They now dead and dont respond to chargers. Would e.g. a 210 shot (like a defribulator) or similar do it? Or are the batt's dumpers?

On Mon, 31 Dec 2012 13:15:19 -0800 (PST), Jaime Dixon wrote:

Similar prob:? --2 year illness meant no charging of two gardening
strimmer and cutter batteries. They now dead and dont respond to
chargers. Would e.g. a 210 shot (like a defribulator) or similar do
it? Or are the batt's dumpers?

What technology are the batteries?

--
Cheers
Dave.

On Monday, December 31, 2012 9:15:19 PM UTC, Jaime Dixon wrote:

Similar prob:? --2 year illness meant no charging of two gardening strimmer and cutter batteries. They now dead and dont respond to chargers. Would e.g. a 210 shot (like a defribulator) or similar do it? Or are the batt's dumpers?


If they're lead acid, I've heard of people applying relatively high voltage to them to get them going again, but it needs current limiting, multiple cycling and you don't get good capacity in the end.

NiCd and NiMH are practically unrepairable. There are 2 ways to fix them, but neither is really practical.

Lithium I'm not familiar with any repair mthods


NT

In message ,
writes
On Monday, December 31, 2012 9:15:19 PM UTC, Jaime Dixon wrote:

Similar prob:? --2 year illness meant no charging of two gardening
strimmer and cutter batteries. They now dead and dont respond to
chargers. Would e.g. a 210 shot (like a defribulator) or similar do
it? Or are the batt's dumpers?


If they're lead acid, I've heard of people applying relatively high
voltage to them to get them going again, but it needs current limiting,
multiple cycling and you don't get good capacity in the end.

Oh. I am attempting to recover a pair of deep cycle lead acid batteries
from my daughter's houseboat. Why don't they teach women to look after
batteries as well as babies etc.!

Initially showing 2-3Volts eventually climbed up to 13.6V but only
taking a charge of 2 amps. I plan to fully discharge at 4 amps (if I can
find a suitable headlamp bulb) and then re-charge.

The engine battery shows full Volts but will not take a charge......

NiCd and NiMH are practically unrepairable. There are 2 ways to fix
them, but neither is really practical.

Lithium I'm not familiar with any repair mthods


NT

--
Tim Lamb

On Monday, December 31, 2012 9:15:19 PM UTC, Jaime Dixon wrote:
On Friday, December 28, 2012 9:05:27 PM UTC, Rick Hughes wrote... Anybody know of a simpler circuit ... all I need is ability to charge 6 & 12 V batteries, non-deep cycle.



Similar prob:? --2 year illness meant no charging of two gardening strimmer and cutter batteries. They now dead and dont respond to chargers. Would e.g. a 210 shot (like a defribulator) or similar do it? Or are the batt's dumpers?

You can supply a de-sulphiting pulse, it's not that high a voltage just enough to be above cell gassing limit.

On Tue, 1 Jan 2013 04:04:06 -0800 (PST), wrote:

Lithium I'm not familiar with any repair mthods

Not worth taking the chance, imo.
Lithium is a treacherous chemistry, ready to **** you up the arse with
the slightest provocation after it's been annoyed enough.
Iow, if the lithium cell has been under or over charged, bin it. Don't
risk your house burning down or your hand been blown off.

wrote in message
...
On Monday, December 31, 2012 9:15:19 PM UTC, Jaime Dixon wrote:
On Friday, December 28, 2012 9:05:27 PM UTC, Rick Hughes wrote... Anybody
know of a simpler circuit ... all I need is ability to charge 6 & 12 V
batteries, non-deep cycle.



Similar prob:? --2 year illness meant no charging of two gardening
strimmer and cutter batteries. They now dead and dont respond to
chargers. Would e.g. a 210 shot (like a defribulator) or similar do it?
Or are the batt's dumpers?

You can supply a de-sulphiting pulse, it's not that high a voltage just
enough to be above cell gassing limit.


You can buy a kit to make one
http://www.ebay.co.uk/itm/190740037894


-

On 02/01/2013 15:20, Mark wrote:
wrote in message
...
On Monday, December 31, 2012 9:15:19 PM UTC, Jaime Dixon wrote:
On Friday, December 28, 2012 9:05:27 PM UTC, Rick Hughes wrote... Anybody
know of a simpler circuit ... all I need is ability to charge 6 & 12 V
batteries, non-deep cycle.



Similar prob:? --2 year illness meant no charging of two gardening
strimmer and cutter batteries. They now dead and dont respond to
chargers. Would e.g. a 210 shot (like a defribulator) or similar do it?
Or are the batt's dumpers?

You can supply a de-sulphiting pulse, it's not that high a voltage just
enough to be above cell gassing limit.


You can buy a kit to make one
http://www.ebay.co.uk/itm/190740037894



good link ... Thnx

On Wed, 02 Jan 2013 22:08:38 +0000, Rick Hughes
wrote:

You can buy a kit to make one
http://www.ebay.co.uk/itm/190740037894

good link ... Thnx

I bought one of their built ones a couple of years ago.
It's been successful enough to make it worth its while.
http://www.courtiestown.co.uk/index....sulphator.html
They didn't have the LVC option then - that would be handy.