Float charge 12v car battery?

[~misfit~]

I have a 'parts car' that has a good battery that I don't want to die due to
negligence. I don't have a battery charger and was wondering if I can
re-purpose an Asian LED driver and laptop PSU to supply a constant 'float
charge'?

If so what voltage / current should I feed it for medium to long term
storage?

Thanks,
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[Sylvia Else]

On 21/06/2018 11:47 AM, ~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to die due to
negligence. I don't have a battery charger and was wondering if I can
re-purpose an Asian LED driver and laptop PSU to supply a constant 'float
charge'?

If so what voltage / current should I feed it for medium to long term
storage?

Thanks,

See

<http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery>

For good results the float voltage needs to be accurately controlled,
and temperature compensated, and there needs to be an occasional
equalisation charge, which is presumably why cheap chargers stuff the
battery up in fairly short order.

Sylvia.

 

[Computer Nerd Kev]

~misfit~ <shaun.at.pukekohe@gmail.com> wrote:

I have a 'parts car' that has a good battery that I don't want to die due to
negligence. I don't have a battery charger and was wondering if I can
re-purpose an Asian LED driver and laptop PSU to supply a constant 'float
charge'?

If so what voltage / current should I feed it for medium to long term
storage?

I don't know off the top of my head, but if I wanted to do it I'd first
try to find some of the magazine articles covering car battery charger
projects and see what figures they went by for the "float" charging
mode.

That "Battery University" website might also have some useful info.

Though I imagine that most people who need those battery trickle
chargers do so more due to the power drawn by the electronics in a
rarely used car than the battery discharging by itself. I'm not
sure to what extent it will help for storage.

--
__ __
#_ < |\| |< _#

 

[Pete]

~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to die due to
negligence. I don't have a battery charger and was wondering if I can
re-purpose an Asian LED driver and laptop PSU to supply a constant 'float
charge'?

If so what voltage / current should I feed it for medium to long term
storage?

The LED driver will probably be constant current. For a car battery,
you need a constant voltage. Sources vary, but between 13.5v and 13.8v
should be fine for a float charge.

Peter

 

[~misfit~]

Once upon a time on usenet Sylvia Else wrote:

On 21/06/2018 11:47 AM, ~misfit~ wrote:
I have a 'parts car' that has a good battery that I don't want to
die due to negligence. I don't have a battery charger and was
wondering if I can re-purpose an Asian LED driver and laptop PSU to
supply a constant 'float charge'?

If so what voltage / current should I feed it for medium to long term
storage?

Thanks,


See

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

For good results the float voltage needs to be accurately controlled,
and temperature compensated, and there needs to be an occasional
equalisation charge, which is presumably why cheap chargers stuff the
battery up in fairly short order.

Thanks Sylvia.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[~misfit~]

Once upon a time on usenet Pete wrote:

~misfit~ wrote:
I have a 'parts car' that has a good battery that I don't want to
die due to negligence. I don't have a battery charger and was
wondering if I can re-purpose an Asian LED driver and laptop PSU to
supply a constant 'float charge'?

If so what voltage / current should I feed it for medium to long term
storage?

The LED driver will probably be constant current. For a car battery,
you need a constant voltage. Sources vary, but between 13.5v and
13.8v should be fine for a float charge.

Cheers Peter. I have a couple different LED drivers that do both CC and CV
(adjustable). I might whack it on at 13.7 and an amp for now (unless
Sylvia's link says otherwise).
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[~misfit~]

Once upon a time on usenet Computer Nerd Kev wrote:

~misfit~ <shaun.at.pukekohe@gmail.com> wrote:
I have a 'parts car' that has a good battery that I don't want to
die due to negligence. I don't have a battery charger and was
wondering if I can re-purpose an Asian LED driver and laptop PSU to
supply a constant 'float charge'?

If so what voltage / current should I feed it for medium to long term
storage?

I don't know off the top of my head, but if I wanted to do it I'd
first try to find some of the magazine articles covering car battery
charger projects and see what figures they went by for the "float"
charging mode.

That "Battery University" website might also have some useful info.

Though I imagine that most people who need those battery trickle
chargers do so more due to the power drawn by the electronics in a
rarely used car than the battery discharging by itself. I'm not
sure to what extent it will help for storage.

Thanks Kev. I'm worried because I was in a similar situation a decade or so
ago and kept the 'spare' battery for a year or so. When I went to use it
again it was dead as a doornail and I couldn't get it to take a charge
again. I have a bit of info now so off to read Batteryuniversity site...
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[news18]

On Thu, 21 Jun 2018 13:47:32 +1200, ~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to die
due to negligence. I don't have a battery charger and was wondering if I
can re-purpose an Asian LED driver and laptop PSU to supply a constant
'float charge'?

A good way to destroy it.

If so what voltage / current should I feed it for medium to long term
storage?

Pick up battery charger designed for purpose and one a week, use 10% of
capacity then recharge it. I forget the voltage, but lead acid batteries
need to be charged at an optimal voltage and they need exercise to keep
them fit.

 

[~misfit~]

Once upon a time on usenet ~misfit~ wrote:

Once upon a time on usenet Pete wrote:
~misfit~ wrote:
I have a 'parts car' that has a good battery that I don't want to
die due to negligence. I don't have a battery charger and was
wondering if I can re-purpose an Asian LED driver and laptop PSU to
supply a constant 'float charge'?

If so what voltage / current should I feed it for medium to long
term storage?

The LED driver will probably be constant current. For a car battery,
you need a constant voltage. Sources vary, but between 13.5v and
13.8v should be fine for a float charge.

Cheers Peter. I have a couple different LED drivers that do both CC
and CV (adjustable). I might whack it on at 13.7 and an amp for now
(unless Sylvia's link says otherwise).

I fed it 13.8v and an amp and after a few hours the charge it was taking
dropped gradually to 0.25A so I'm assuming that it's topped off.

Thanks to all for the input.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[John_H]

~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to die due to
negligence. I don't have a battery charger and was wondering if I can
re-purpose an Asian LED driver and laptop PSU to supply a constant 'float
charge'?

If so what voltage / current should I feed it for medium to long term
storage?

14.2 will keep it fully charged although you can float it on less. If
you happen to have a 13.8V regulated power supply it's a convenient
way to go.

If you have a solar panel Oatley Electronics sell a nice little
regulator kit for around $25 which is ideal for the purpose.

--
John H

 

[~misfit~]

Once upon a time on usenet John_H wrote:

~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to
die due to negligence. I don't have a battery charger and was
wondering if I can re-purpose an Asian LED driver and laptop PSU to
supply a constant 'float charge'?

If so what voltage / current should I feed it for medium to long term
storage?

14.2 will keep it fully charged although you can float it on less. If
you happen to have a 13.8V regulated power supply it's a convenient
way to go.

If you have a solar panel Oatley Electronics sell a nice little
regulator kit for around $25 which is ideal for the purpose.

I have a solar car battery float charge thing about the size of a car sun
visor I got from Jaycar a few years back (I don't shop there any more) but
with that thing plugged into the cigarette lighter for a couple of weeks the
battery actually got flatter! (In the car I have the cigarette lighter is
always connected regardless of key position.)

I don't suppose you could give me a link to the Oatley thing? I'm in NZ so
shipping would probably be prohibitive but I'm curious. I've cut the
regulator off the Jaycar panel and just the panel outputs 24v in sunlight.
I'm not sure how many (milli)amps it will deliver though, haven't tested
that yet.

Cheers,
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[John_H]

~misfit~ wrote:

Once upon a time on usenet John_H wrote:

If you have a solar panel Oatley Electronics sell a nice little
regulator kit for around $25 which is ideal for the purpose.

I don't suppose you could give me a link to the Oatley thing? I'm in NZ so
shipping would probably be prohibitive but I'm curious.

http://oatleyelectronics.com//product_info.php?cPath=21&products_id=688

You can download the notes but not the schematic IIRC. The less
common components, with the exception of the PCB, should all be
available through AliExpress if you can dig up a cct from somewhere.

The original was published in Silicon Chip but Oatley have since
modified it considerably.

--
John H

 

[news18]

On Sun, 24 Jun 2018 16:07:05 +1200, ~misfit~ wrote:

Once upon a time on usenet John_H wrote:
~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to die
due to negligence. I don't have a battery charger and was wondering if
I can re-purpose an Asian LED driver and laptop PSU to supply a
constant 'float charge'?

If so what voltage / current should I feed it for medium to long term
storage?

14.2 will keep it fully charged although you can float it on less. If
you happen to have a 13.8V regulated power supply it's a convenient way
to go.

If you have a solar panel Oatley Electronics sell a nice little
regulator kit for around $25 which is ideal for the purpose.

I have a solar car battery float charge thing about the size of a car
sun visor I got from Jaycar a few years back (I don't shop there any
more) but with that thing plugged into the cigarette lighter for a
couple of weeks the battery actually got flatter! (In the car I have the
cigarette lighter is always connected regardless of key position.)

I don't suppose you could give me a link to the Oatley thing? I'm in NZ
so shipping would probably be prohibitive but I'm curious. I've cut the
regulator off the Jaycar panel and just the panel outputs 24v in
sunlight. I'm not sure how many (milli)amps it will deliver though,
haven't tested that yet.

I've no experience with the vehicle sun screen solar panel you purchased
from Jaycar, but the basic battery charger/solar panel regulator they
were selling comes set to SLA chartging and you need to change it to
output for wet cells if that is your type of battery.

the solart panel probably didn't do anything as the panel was't in optmal
conditions, aka facing north and perpendicular to rays from full sun.
also a good change that being in a closed car in full sun, the output was
limited by thermal load.

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

Cheers,

 

[~misfit~]

Once upon a time on usenet news18 wrote:

On Sun, 24 Jun 2018 16:07:05 +1200, ~misfit~ wrote:

Once upon a time on usenet John_H wrote:
~misfit~ wrote:

I have a 'parts car' that has a good battery that I don't want to
die due to negligence. I don't have a battery charger and was
wondering if I can re-purpose an Asian LED driver and laptop PSU
to supply a constant 'float charge'?

If so what voltage / current should I feed it for medium to long
term storage?

14.2 will keep it fully charged although you can float it on less.
If you happen to have a 13.8V regulated power supply it's a
convenient way to go.

If you have a solar panel Oatley Electronics sell a nice little
regulator kit for around $25 which is ideal for the purpose.

I have a solar car battery float charge thing about the size of a car
sun visor I got from Jaycar a few years back (I don't shop there any
more) but with that thing plugged into the cigarette lighter for a
couple of weeks the battery actually got flatter! (In the car I have
the cigarette lighter is always connected regardless of key
position.)

I don't suppose you could give me a link to the Oatley thing? I'm in
NZ so shipping would probably be prohibitive but I'm curious. I've
cut the regulator off the Jaycar panel and just the panel outputs
24v in sunlight. I'm not sure how many (milli)amps it will deliver
though, haven't tested that yet.

I've no experience with the vehicle sun screen solar panel you
purchased from Jaycar, but the basic battery charger/solar panel
regulator they were selling comes set to SLA chartging and you need
to change it to output for wet cells if that is your type of battery.

the solart panel probably didn't do anything as the panel was't in
optmal conditions, aka facing north and perpendicular to rays from
full sun. also a good change that being in a closed car in full sun,
the output was limited by thermal load.

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

I don't know my meter only goes up to 10A and the fuses aren't cheap.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[~misfit~]

Once upon a time on usenet John_H wrote:

~misfit~ wrote:
Once upon a time on usenet John_H wrote:

If you have a solar panel Oatley Electronics sell a nice little
regulator kit for around $25 which is ideal for the purpose.

I don't suppose you could give me a link to the Oatley thing? I'm in
NZ so shipping would probably be prohibitive but I'm curious.

http://oatleyelectronics.com//product_info.php?cPath=21&products_id=688

You can download the notes but not the schematic IIRC. The less
common components, with the exception of the PCB, should all be
available through AliExpress if you can dig up a cct from somewhere.

The original was published in Silicon Chip but Oatley have since
modified it considerably.

Thanks John.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[news18]

On Sun, 24 Jun 2018 19:35:53 +1200, ~misfit~ wrote:

I have a solar car battery float charge thing about the size of a car
sun visor I got from Jaycar a few years back (I don't shop there any
more) but with that thing plugged into the cigarette lighter for a
couple of weeks the battery actually got flatter! (In the car I have
the cigarette lighter is always connected regardless of key position.)

I don't suppose you could give me a link to the Oatley thing? I'm in
NZ so shipping would probably be prohibitive but I'm curious. I've cut
the regulator off the Jaycar panel and just the panel outputs 24v in
sunlight. I'm not sure how many (milli)amps it will deliver though,

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

I don't know my meter only goes up to 10A and the fuses aren't cheap.

Which is what I get out of a 120watt full solar panel, so it would have
to be incredible if something the size of a car visor got anywhere near
it. Stick some "resistance" in the circuit at first.

 

[John_H]

~misfit~ wrote:

Once upon a time on usenet news18 wrote:

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

I don't know my meter only goes up to 10A and the fuses aren't cheap.

You don't need to measure the current. Load the panel with a wire
wound resistor (22 ohm ought do) and measure the voltage when it's
facing the sun. Ohm's Law being the clue.

Don't hang about too long as the resistor is likely to get very hot.

Power (which is what you really need to know) = V^2/R.

--
John H

 

[~misfit~]

Once upon a time on usenet news18 wrote:

On Sun, 24 Jun 2018 19:35:53 +1200, ~misfit~ wrote:


I have a solar car battery float charge thing about the size of a
car sun visor I got from Jaycar a few years back (I don't shop
there any more) but with that thing plugged into the cigarette
lighter for a couple of weeks the battery actually got flatter!
(In the car I have the cigarette lighter is always connected
regardless of key position.)

I don't suppose you could give me a link to the Oatley thing? I'm
in NZ so shipping would probably be prohibitive but I'm curious.
I've cut the regulator off the Jaycar panel and just the panel
outputs 24v in sunlight. I'm not sure how many (milli)amps it will
deliver though,

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

I don't know my meter only goes up to 10A and the fuses aren't cheap.

Which is what I get out of a 120watt full solar panel, so it would
have to be incredible if something the size of a car visor got
anywhere near it. Stick some "resistance" in the circuit at first.

Yeah I mis-read, checking the newsgroup quickly. I thought he meant SCC of
the battery!
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[~misfit~]

Once upon a time on usenet John_H wrote:

~misfit~ wrote:
Once upon a time on usenet news18 wrote:

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

I don't know my meter only goes up to 10A and the fuses aren't cheap.

You don't need to measure the current. Load the panel with a wire
wound resistor (22 ohm ought do) and measure the voltage when it's
facing the sun. Ohm's Law being the clue.

Don't hang about too long as the resistor is likely to get very hot.

Power (which is what you really need to know) = V^2/R.

Thanks. I mis-read when checking the newsgroup quickly. I thought you meant
SCC of the battery! I'll check the solar panel when I get a chance. It's
'stored' so might take some finding.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

 

[~misfit~]

Once upon a time on usenet ~misfit~ wrote:

Once upon a time on usenet John_H wrote:
~misfit~ wrote:
Once upon a time on usenet news18 wrote:

You've posted the OCV(open circuit voltage),
What is the SCC(short circuit current)?

I don't know my meter only goes up to 10A and the fuses aren't
cheap.

You don't need to measure the current. Load the panel with a wire
wound resistor (22 ohm ought do) and measure the voltage when it's
facing the sun. Ohm's Law being the clue.

Don't hang about too long as the resistor is likely to get very hot.

Power (which is what you really need to know) = V^2/R.

Thanks. I mis-read when checking the newsgroup quickly. I thought you
meant SCC of the battery! I'll check the solar panel when I get a
chance. It's 'stored' so might take some finding.

Also we've not had any really sunny days here for a while.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)