sla charging schematics ?

[mark krawczuk]

hi, after some schematics to charge 6 volt and 12 volt sla ( sealed lead
acid ) batteries.... basically dont need to charge them flat out , cause
they dont get used much, something i can leave on trickle charge for a week
or so , would be good....

any body have any or know of any links ?

 

[Martin]

"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:YtedncSTb-DDk5LRnZ2dnUVZ_u6dnZ2d@adnap.net.au...

hi, after some schematics to charge 6 volt and 12 volt sla ( sealed lead
acid ) batteries.... basically dont need to charge them flat out , cause
they dont get used much, something i can leave on trickle charge for a
week or so , would be good....

any body have any or know of any links ?


Go to 'jaycar' spend $59.95 and buy one of these.

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD


No point in messing around getting the parts and building one. Probably cost
more.

Just check the rating you need before you buy.

 

[Phil Allison]

"Martin"

Go to 'jaycar' spend $59.95 and buy one of these.

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD

** No way unless you want your SLAs to explode.

Jaycar have this charger for SLA batteries:

http://www.jaycar.com.au/productView.asp?ID=MB3603&CATID=18&form=CAT&SUBCATID=295

However, WES have 1 amp SLA chargers in 6 and 12 volt for less than half the
Jaycar price.



..... Phil

 

[mark krawczuk]

hi, thanks, but i really want to make one not buy one, i reckon i`ve seen
one using a lm317 , but cant find the schematic , and it would have cost
only 4 or 5 $ !!!

i`ve got a heap of electronic conponents , so i`d rather use them , than
keep buying ready made stuff.....

mark k



"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:878khfFpg2U1@mid.individual.net...

"Martin"

Go to 'jaycar' spend $59.95 and buy one of these.

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD


** No way unless you want your SLAs to explode.

Jaycar have this charger for SLA batteries:

http://www.jaycar.com.au/productView.asp?ID=MB3603&CATID=18&form=CAT&SUBCATID=295

However, WES have 1 amp SLA chargers in 6 and 12 volt for less than half
the Jaycar price.



.... Phil

 

[Grant]

On Wed, 9 Jun 2010 17:36:47 +0930, "mark krawczuk" <krawczuk@adam.com.au> wrote:

hi, thanks, but i really want to make one not buy one, i reckon i`ve seen
one using a lm317 , but cant find the schematic , and it would have cost
only 4 or 5 $ !!!

i`ve got a heap of electronic conponents , so i`d rather use them , than
keep buying ready made stuff.....

Just make the usual LM317 circuit, but 100 or 120 Ohm resistor for the
output to adj terminal to soak up the quiescent current, and put a series
diode from LM317 output to battery to stop the battery powering up the
charger when the mains is off. Appropriate R and trimpot from Adj to
ground for desired output, add a switch for 6 and 12V operation -- no
magic there.

Set output voltage for say 13.5V float on 12V, half that for 6V battery,
only need small heatsink on the LM317.

The schematic is basically from datasheet with the extra diode and lower
Adj resistor. If you want reverse battery protection, add another diode
from battery minus to the series diode's cathode, and put in a polyswitch
or normal fuse to the battery.

Grant.
--
http://bugs.id.au/

 

[Martin]

"mark krawczuk" <krawczuk@adam.com.au> wrote in message
news:wYCdnVDK6v8i1pLRnZ2dnUVZ_j-dnZ2d@adnap.net.au...

hi, thanks, but i really want to make one not buy one, i reckon i`ve
seen one using a lm317 , but cant find the schematic , and it would have
cost only 4 or 5 $ !!!

i`ve got a heap of electronic conponents , so i`d rather use them , than
keep buying ready made stuff.....
8

You didn't mention that. Sorry.

 

[Martin]

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:878khfFpg2U1@mid.individual.net...

"Martin"

Go to 'jaycar' spend $59.95 and buy one of these.

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD


** No way unless you want your SLAs to explode.

No doubt you have a reason to state the above. But I just contacted 'jaycar'

and they informed me that the above was fine on SLA's on a the trickle
setting. But then you never know I suppose. Don't think I'll bother next
time.

 

[John Tserkezis]

Phil Allison wrote:

Go to 'jaycar' spend $59.95 and buy one of these.
http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD

** No way unless you want your SLAs to explode.
Jaycar have this charger for SLA batteries:
http://www.jaycar.com.au/productView.asp?ID=MB3603&CATID=18&form=CAT&SUBCATID=295
However, WES have 1 amp SLA chargers in 6 and 12 volt for less than half the
Jaycar price.

Those suggestions are nice, and cheaper than the DIY method, are a lot
easier, probably a lot better, but they don't help the original poster
with his school project.

His suggestion of using an LM317 adjustable regulator is probably the
more expensive option other than a fixed regulator which is cheaper, and
that you can regulate anyway.

It smells like a school project, and non-compliance with component
requirement would result in a fail.


Remember, his quoted prices of $4-$5 is component value only (and I
think is still overestimated) and of course does not include heatsink,
power supply, wiring, clamps, connectors, case etc, because the school
is only interested in the design.



Unless of course Mark can show he *can* build it for $4-$5 complete,
instead of the commercial ~$30 or so. In single quantities of course.
In bulk orders, China can build them for less than his quote anyway.

 

[John Tserkezis]

Martin wrote:

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD

** No way unless you want your SLAs to explode.

No doubt you have a reason to state the above. But I just contacted 'jaycar'
and they informed me that the above was fine on SLA's on a the trickle
setting. But then you never know I suppose. Don't think I'll bother next
time.

He's probably right on this one. (odd, I'm on Phil's side for once..).

Be careful what you state about Jaycar gear unless you test and
evaluate it properly.

The term "trickle" when it comes to lead-acid batteries can mean MANY
things. Usually it means a less-than-full charge rate that is selected
when the full rate charge is over.
In other words, if you leave it long enough, you will fry your battery
anyway.

What you want, is a float charge. If they *meant* a float charge, they
would have SAID float charge. And in fact, they DO say float on some of
their other chargers.


The SLA battery may not "explode", but at the end of the day, there's
little difference between "explode" and "molten mass of toxic, corrosive
goop all over the desk".



But hey, it's your money.

 

[terryc]

On Thu, 10 Jun 2010 10:30:03 +1000, Martin wrote:

"Phil Allison" <phil_a@tpg.com.au> wrote in message
news:878khfFpg2U1@mid.individual.net...

"Martin"

Go to 'jaycar' spend $59.95 and buy one of these.

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%
2D3522&form=KEYWORD


** No way unless you want your SLAs to explode.

No doubt you have a reason to state the above.

I don't know about him but for SLa I'd aim at C/20, so they would be fine
for 160AmpsHr SLA (and at that size you could buy twice the capacity of
simple Deep Discharge Lead Acid batteries(at a decent battery seller and
not chains).

But I just contacted
'jaycar' and they informed me that the above was fine on SLA's on a the
trickle setting.

What was the current of the trickle current? That is the catch 22. IME,
most SLAs are small stuff and the Jaycar plugpack SLA (@375ma?) can stuff
those if left on continuously.

 

[terryc]

On Thu, 10 Jun 2010 10:32:44 +1000, John Tserkezis wrote:

It smells like a school project, and non-compliance with component
requirement would result in a fail.

What level and what subject would they do this?

 

[Phil Allison]

"Martin"

"Phil Allison"
"Martin"

Go to 'jaycar' spend $59.95 and buy one of these.

http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD


** No way unless you want your SLAs to explode.

No doubt you have a reason to state the above. But I just contacted
'jaycar' and they informed me that the above was fine on SLA's on a the
trickle setting.

** Well - Jaycar would say that, wouldn't they ?

But unless the SLA is a VERY large example, that 8 amp charger will
certainly damage it on either setting.

But then you never know I suppose. Don't think I'll bother next time.

** Despite appearances, battery chargers that work well, are safe for the
battery and the user under all conditions are NOT trivial designs.

The AC transformers used in mains powered types have to be sized just right
for the intended battery type and also must meet class 2 insulation and
safety requirements - they are "prescribed items" under the electrical
safety laws for that reason.

You are NOT likely to find anything suitable in your junk box !!!

Lead acid car battery chargers are NOT safe with SLA batteries, or any
other type AFAIK.

It is very much a game of horses for courses.


..... Phil

 

[John Tserkezis]

terryc wrote:

It smells like a school project, and non-compliance with component
requirement would result in a fail.

What level and what subject would they do this?

Subject? Er, when I was in school they called it "Electronics". Who
would have thought? And that was starting in year 8 or 9 I think.

As far as level goes, this would require complicated mathematics
involving multiplication AND division, also with addition and
subtraction. So that would be around year 10 or so?

As long as you can teach the principal of voltage offsets, past that,
the above maths apply.

But half the time they never bothered to properly explain theory of
operation either. Shut up, here's a project, make the board and put it
together.

A pass if yours flashes the lights in the correct order, and an
automatic fail if you ask stupid questions like "what does it do?".


They don't teach you, (and you don't have to know) the detailed
workings of the inndards of the component you're working with, basic
theory of operation is enough to get you by for now.

They taught us all about resistors and capacitors, but I didn't really
get to know all the implications of each type till well into my career.
And even then, the importance of some types over others in specific
applications. Especially the more common applications where you might
know *why* it's there, but not that you should be using a particular
grade of component there regardless of the fact that "everyone else"
appears to use garden variety.


My point being, perhaps not with "school" but with private tutoring,
you can get on your way with apparently complex components in albeit
non-critical applications very early.

 

[mark krawczuk]

mmmmm * found * a circuit, using a lm317, 3 resisters, 2 capacitors ,
which i think comes in well under 5$

i wasnt talking about the transformer , only the circuit,,,,


"John Tserkezis" <jt@techniciansyndrome.org.invalid> wrote in message
news:4c1032ac$0$26118$afc38c87@news.optusnet.com.au...

Phil Allison wrote:

Go to 'jaycar' spend $59.95 and buy one of these.
http://www.jaycar.com.au/productView.asp?ID=MB3522&keywords=MB%2D3522&form=KEYWORD

** No way unless you want your SLAs to explode.
Jaycar have this charger for SLA batteries:
http://www.jaycar.com.au/productView.asp?ID=MB3603&CATID=18&form=CAT&SUBCATID=295
However, WES have 1 amp SLA chargers in 6 and 12 volt for less than half
the
Jaycar price.

Those suggestions are nice, and cheaper than the DIY method, are a lot
easier, probably a lot better, but they don't help the original poster
with his school project.

His suggestion of using an LM317 adjustable regulator is probably the
more expensive option other than a fixed regulator which is cheaper, and
that you can regulate anyway.

It smells like a school project, and non-compliance with component
requirement would result in a fail.


Remember, his quoted prices of $4-$5 is component value only (and I
think is still overestimated) and of course does not include heatsink,
power supply, wiring, clamps, connectors, case etc, because the school
is only interested in the design.



Unless of course Mark can show he *can* build it for $4-$5 complete,
instead of the commercial ~$30 or so. In single quantities of course.
In bulk orders, China can build them for less than his quote anyway.

 

[mark krawczuk]

its not a school project , and so what if it was ????



"terryc" <newsninespam-spam@woa.com.au> wrote in message
news:hupekt$7sl$2@speranza.aioe.org...

On Thu, 10 Jun 2010 10:32:44 +1000, John Tserkezis wrote:


It smells like a school project, and non-compliance with component
requirement would result in a fail.

What level and what subject would they do this?

 

[John Tserkezis]

mark krawczuk wrote:

its not a school project , and so what if it was ????

I'm not doing your homework for you.

The answers you seek are available on the net, which you clearly have
access to since you're posting on newsgroups.

 

[Charlie+]

On Wed, 9 Jun 2010 13:14:58 +0930, "mark krawczuk" <krawczuk@adam.com.au>
wrote as :

hi, after some schematics to charge 6 volt and 12 volt sla ( sealed lead
acid ) batteries.... basically dont need to charge them flat out , cause
they dont get used much, something i can leave on trickle charge for a week
or so , would be good....

any body have any or know of any links ?

Try take a look at the C200 data sheet, you can make a charger from

schematics on there with settable max charge rate AND settable max V with
this chip - total cost of charger probably around Ł10. If C200 are still
available!
Much cheaper if you use a C200 ic plus bits out of your scrap boxes!
Charlie+

 

[Charlie+]

On Thu, 10 Jun 2010 08:04:06 +0100, Charlie+ <charlie@xxx.net> wrote as :

On Wed, 9 Jun 2010 13:14:58 +0930, "mark krawczuk" <krawczuk@adam.com.au
wrote as :

hi, after some schematics to charge 6 volt and 12 volt sla ( sealed lead
acid ) batteries.... basically dont need to charge them flat out , cause
they dont get used much, something i can leave on trickle charge for a week
or so , would be good....

any body have any or know of any links ?

Try take a look at the C200 data sheet, you can make a charger from
schematics on there with settable max charge rate AND settable max V with
this chip - total cost of charger probably around Ł10. If C200 are still
available!
Much cheaper if you use a C200 ic plus bits out of your scrap boxes!

Sorry in above post - for C200 Read L200 and here is any ole website from
search, with schematic ....
http://www.zen22142.zen.co.uk/Circuits/Power/l200.html
Charlie+

 

[terryc]

On Thu, 10 Jun 2010 15:36:49 +0930, mark krawczuk wrote:

its not a school project , and so what if it was ????

As John said. It is basically my undestanding of the level at which this
might be YOUR project. In which case, you should be able to do something
as basic as search the internet and find a circuit that could be used and/
or modified.

The point about school work is that you should do the work and learn from
it and this is actually a good project for that. You do not learn much,
if anything if it is dished up to you.

Well, that has been given to you anyway. Now your job is to build it.

Good luck.

 

[terryc]

On Thu, 10 Jun 2010 16:05:55 +1000, John Tserkezis wrote:

Subject? Er, when I was in school they called it "Electronics". Who
would have thought? And that was starting in year 8 or 9 I think.

Wow, something useful,,,, or not. I thought it was mostly mickey mouse
subects now.

They don't teach you, (and you don't have to know) the detailed
workings of the inndards of the component you're working with, basic
theory of operation is enough to get you by for now.

Circuit analysis, 2nd year uni for me.

My point being, perhaps not with "school" but with private tutoring,
you can get on your way with apparently complex components in albeit
non-critical applications very early.

Yes.