Charge Regulators vs Voltage Regulators

[Josiah]

I am making a 12v battery charger. The thing is I don't want to ruin
my batteries due to overcharging. So I've been researching charge
regulators and voltage regulators, but everything I've found seems to
be major overkill and too costly for what I am doing.

I have made a solar panel made up of 16, 3v / 40mA solar cells. It has
4 rows of 4. Each row is made up 4 cells wired in parallel, then the
rows are stacked and wired in series so the end result is 12v / 160mA.

Is there any kind of voltage or charge regulator I can build that
deals with 12v / 160mA? Instead of these expensive 12v / 5 Amp+ ones
I am finding?

Thanks for any help you can give me 
~Meanmon13~

P.s.: I'm only going to need 1 diode for this simple charger right?

 

[Jeff Liebermann]

On 20 Mar 2004 20:04:48 -0800, Meanmon13@hotmail.com (Josiah) wrote:

I am making a 12v battery charger.

What kind of batteries do you have? Different battery types and sizes
require different methods of charging. Be specific (mfg and part
number).

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# jeffl@comix.santa-cruz.ca.us
# 831.421.6491 digital_pager jeffl@cruzio.com AE6KS

 

[Ken Smith]

In article <96ffefc0.0403202004.4307023d@posting.google.com>,
Josiah <Meanmon13@hotmail.com> wrote:

I am making a 12v battery charger. The thing is I don't want to ruin

I assume these are 12V nominal lead acid batteries.

rows are stacked and wired in series so the end result is 12v / 160mA.

What is the unloaded voltage of the panel? If it is under 13V the design
will be fairly easy.

Is there any kind of voltage or charge regulator I can build that
deals with 12v / 160mA?

Yes there is. If your panel has an upper limit of voltage lower than the
float voltage, the heart of the charger will be a very simple booster.


Instead of these expensive 12v / 5 Amp+ ones

I am finding?

Thanks for any help you can give me 
~Meanmon13~

P.s.: I'm only going to need 1 diode for this simple charger right?

--
--
kensmith@rahul.net forging knowledge

 

[R.Legg]

Meanmon13@hotmail.com (Josiah) wrote in message news:<96ffefc0.0403202004.4307023d@posting.google.com>...

I am making a 12v battery charger. The thing is I don't want to ruin
my batteries due to overcharging. So I've been researching charge
regulators and voltage regulators, but everything I've found seems to
be major overkill and too costly for what I am doing.

I have made a solar panel made up of 16, 3v / 40mA solar cells. It has
4 rows of 4. Each row is made up 4 cells wired in parallel, then the
rows are stacked and wired in series so the end result is 12v / 160mA.

Is there any kind of voltage or charge regulator I can build that
deals with 12v / 160mA? Instead of these expensive 12v / 5 Amp+ ones
I am finding?

Below a certain weight, I don't think the major cost is in the actual
power delivery components, it's in the battery gauge controller and
the safety package. If everyone were using the same kind of batteries,
the cost would go down.

If you are using VRLA batteries, which you don't actually say, then
you should use a conventional float voltage charger, as these are
commodity items and avoid problems with gauging the charge or the AH
rating. Current rating refers only to the current delivered prior to
entering float voltage range, which is characteristic for all
lead-acid batteries at room temperature, regardless of capacity.

You can build your own, but it generally ends up costing more, unless
you are using materials on-hand and discount your own labor. Linear
Technology, TI, ST Micro, and Nat Semi all make charge controller IC's
for integration into battery charger circuits.

RL


RL

 

[James Meyer]

On 20 Mar 2004 20:04:48 -0800, Meanmon13@hotmail.com (Josiah) posted this:

I have made a solar panel made up of 16, 3v / 40mA solar cells. It has
4 rows of 4. Each row is made up 4 cells wired in parallel, then the
rows are stacked and wired in series so the end result is 12v / 160mA.

Is there any kind of voltage or charge regulator I can build that
deals with 12v / 160mA? Instead of these expensive 12v / 5 Amp+ ones
I am finding?

P.s.: I'm only going to need 1 diode for this simple charger right?

If the battery has a capacity of 2 AmpHours or greater, you don't need a
charge regulator at all! The 160 mA maximum current will be a trickle charge
for a battery large enough and a trickle charge can be left connected to a
battery continusously. Or as long as the sun is shining.

You will only need one diode. But be aware that the diode will subtract
a small amount, .3 to .6 Volts, from the cell's output. If you are charging a
lead-acid battery, then it would be wise to increase the cell's output voltage
by adding one more row of cells for something like 15 volts output.

Jim

 

[Ken Smith]

In article <405EF3EF.6070701@nospam.com>,
Fred Bloggs <nospam@nospam.com> wrote:

One inexpensive way to get a precision cutoff is like so- maybe $5 worth
of components- this has no reverse battery or failsafe overvoltage
protection:
Please view in a fixed-width font such as Courier.


+---------------------------------------------------------+
| |
| |
| +------+----+----------+---------------------+
| | | | | |
| \ \ | | |
| 4.7K 3.3K |C1 | |
| R1 R2 === | |
| / / |0.47U \ 12V
| | | | 47K -----
| | +----+ R3 ---
SOLAR | ARRAY | | / RP _ R4 BATT
+---+---+---+---+ | | | 1K /| 3.9K |
| | | | | | | D1 +-/\/\---/\/\----+----+
| | | | | | | 1N4148 | / | |
+---+---+---+---+ | +-------|>|----|<|---------------+ |
| | | | | | | | LMV431 |
| | | | | | \ \ U1 +---------+
+---+---+---+---+ | 39K 1.2K | |
| | | | | | R5 R6 1N5822 | |
| | | | | | / / D2 --- |
+---+---+---+---+ | | | \ / |
| | | | | +-------------------------+ --- |
| | | | | e | | | | |
+---+---+---+---+ \| | | | | |
| T1 |----+----+----+ | | \
| 2N4403 /| | | | 1K
| c | | T3 | R8
| | 2N4401 c |IRFU220N| /
| | |/ | ||-+ |
| +------+-------| T2 +-----||<- |
| SW1 | | |\ | ||-+ |
| |o \ e /---/ | |
| RST-+ 10K | / \ 20V | |
| |o R7 | --- D3 | |
| | / | | | D4 |
| | | | | | 1N4001 |
| +------+---------+--------+--------+---|<|---+
| |
| |
+-----------------------------------------------+

The LMV431 is a precision programmable zener that is set to trip the
T1-T2 latch and turn T3 off when Vbatt reaches 13.8V (set RP=740 ohms)-
the circuit then goes into trickle charge mode with the array providing
current through R8- battery drain with dark array is negligible, and no
heatsinks necessary

Every night, T1, T2 will be reset by the lack of light and the circuit
will flip back into the fast charge mode. If you change that circuit to
use a CD4000 series logic gate, you can make it remember overnight by
adding a large capacitor. I think that would also lead to a lower
component count circuit.

Move R8 to be in parallel with T3 and you don't need D4.
--
--
kensmith@rahul.net forging knowledge

 

[Fred Bloggs]

I am making a 12v battery charger. The thing is I don't want to ruin
my batteries due to overcharging. So I've been researching charge
regulators and voltage regulators, but everything I've found seems to
be major overkill and too costly for what I am doing.

I have made a solar panel made up of 16, 3v / 40mA solar cells. It has
4 rows of 4. Each row is made up 4 cells wired in parallel, then the
rows are stacked and wired in series so the end result is 12v / 160mA.

Is there any kind of voltage or charge regulator I can build that
deals with 12v / 160mA? Instead of these expensive 12v / 5 Amp+ ones
I am finding?

One inexpensive way to get a precision cutoff is like so- maybe $5 worth
of components- this has no reverse battery or failsafe overvoltage
protection:
Please view in a fixed-width font such as Courier.


+---------------------------------------------------------+
| |
| |
| +------+----+----------+---------------------+
| | | | | |
| \ \ | | |
| 4.7K 3.3K |C1 | |
| R1 R2 === | |
| / / |0.47U \ 12V
| | | | 47K -----
| | +----+ R3 ---
SOLAR | ARRAY | | / RP _ R4 BATT
+---+---+---+---+ | | | 1K /| 3.9K |
| | | | | | | D1 +-/\/\---/\/\----+----+
| | | | | | | 1N4148 | / | |
+---+---+---+---+ | +-------|>|----|<|---------------+ |
| | | | | | | | LMV431 |
| | | | | | \ \ U1 +---------+
+---+---+---+---+ | 39K 1.2K | |
| | | | | | R5 R6 1N5822 | |
| | | | | | / / D2 --- |
+---+---+---+---+ | | | \ / |
| | | | | +-------------------------+ --- |
| | | | | e | | | | |
+---+---+---+---+ \| | | | | |
| T1 |----+----+----+ | | \
| 2N4403 /| | | | 1K
| c | | T3 | R8
| | 2N4401 c |IRFU220N| /
| | |/ | ||-+ |
| +------+-------| T2 +-----||<- |
| SW1 | | |\ | ||-+ |
| |o \ e /---/ | |
| RST-+ 10K | / \ 20V | |
| |o R7 | --- D3 | |
| | / | | | D4 |
| | | | | | 1N4001 |
| +------+---------+--------+--------+---|<|---+
| |
| |
+-----------------------------------------------+

The LMV431 is a precision programmable zener that is set to trip the
T1-T2 latch and turn T3 off when Vbatt reaches 13.8V (set RP=740 ohms)-
the circuit then goes into trickle charge mode with the array providing
current through R8- battery drain with dark array is negligible, and no
heatsinks necessary

 

[Fred Bloggs]

Ken Smith wrote:

In article <405EF3EF.6070701@nospam.com>,
Fred Bloggs <nospam@nospam.com> wrote:

One inexpensive way to get a precision cutoff is like so- maybe $5 worth
of components- this has no reverse battery or failsafe overvoltage
protection:
Please view in a fixed-width font such as Courier.


+---------------------------------------------------------+
| |
| |
| +------+----+----------+---------------------+
| | | | | |
| \ \ | | |
| 4.7K 3.3K |C1 | |
| R1 R2 === | |
| / / |0.47U \ 12V
| | | | 47K -----
| | +----+ R3 ---
SOLAR | ARRAY | | / RP _ R4 BATT
+---+---+---+---+ | | | 1K /| 3.9K |
| | | | | | | D1 +-/\/\---/\/\----+----+
| | | | | | | 1N4148 | / | |
+---+---+---+---+ | +-------|>|----|<|---------------+ |
| | | | | | | | LMV431 |
| | | | | | \ \ U1 +---------+
+---+---+---+---+ | 39K 1.2K | |
| | | | | | R5 R6 1N5822 | |
| | | | | | / / D2 --- |
+---+---+---+---+ | | | \ / |
| | | | | +-------------------------+ --- |
| | | | | e | | | | |
+---+---+---+---+ \| | | | | |
| T1 |----+----+----+ | | \
| 2N4403 /| | | | 1K
| c | | T3 | R8
| | 2N4401 c |IRFU220N| /
| | |/ | ||-+ |
| +------+-------| T2 +-----||<- |
| SW1 | | |\ | ||-+ |
| |o \ e /---/ | |
| RST-+ 10K | / \ 20V | |
| |o R7 | --- D3 | |
| | / | | | D4 |
| | | | | | 1N4001 |
| +------+---------+--------+--------+---|<|---+
| |
| |
+-----------------------------------------------+

The LMV431 is a precision programmable zener that is set to trip the
T1-T2 latch and turn T3 off when Vbatt reaches 13.8V (set RP=740 ohms)-
the circuit then goes into trickle charge mode with the array providing
current through R8- battery drain with dark array is negligible, and no
heatsinks necessary




Every night, T1, T2 will be reset by the lack of light and the circuit
will flip back into the fast charge mode.

It will go into fast charge mode when the array output drops to a very
low voltage so that T1-T2 cannot sustain conduction- but by that time D2
is well into reverse bias so that no current flows out of the battery,
other than the drain through R3-RP-R4 and possibly R2-R6-R5 if the '431
is conducting. When the array is re-illuminated and the output
increases, T1-T2 remain off if Vbatt<13.8 so that T3 turns on at ~3V
array volts but overall bias across D2 is <0 so that charging does not
begin until array output exceeds ~12.5V or more precisely Vbatt+0.5V. If
Vbatt>13.8V as array comes back on line, T1-T2 is tripped on before
charging begins.

If you change that circuit to
use a CD4000 series logic gate, you can make it remember overnight by
adding a large capacitor. I think that would also lead to a lower
component count circuit.

Move R8 to be in parallel with T3 and you don't need D4.

Okay -good point -thnx.

 

[Ken Smith]

In article <405F0741.8030008@nospam.com>,
Fred Bloggs <nospam@nospam.com> wrote:

Ken Smith wrote:
In article <405EF3EF.6070701@nospam.com>,
Fred Bloggs <nospam@nospam.com> wrote:

One inexpensive way to get a precision cutoff is like so- maybe $5 worth
of components- this has no reverse battery or failsafe overvoltage
protection:
Please view in a fixed-width font such as Courier.


+---------------------------------------------------------+
| |
| |
| +------+----+----------+---------------------+
| | | | | |
| \ \ | | |
| 4.7K 3.3K |C1 | |
| R1 R2 === | |
| / / |0.47U \ 12V
| | | | 47K -----
| | +----+ R3 ---
SOLAR | ARRAY | | / RP _ R4 BATT
+---+---+---+---+ | | | 1K /| 3.9K |
| | | | | | | D1 +-/\/\---/\/\----+----+
| | | | | | | 1N4148 | / | |
+---+---+---+---+ | +-------|>|----|<|---------------+ |
| | | | | | | | LMV431 |
| | | | | | \ \ U1 +---------+
+---+---+---+---+ | 39K 1.2K | |
| | | | | | R5 R6 1N5822 | |
| | | | | | / / D2 --- |
+---+---+---+---+ | | | \ / |
| | | | | +-------------------------+ --- |
| | | | | e | | | | |
+---+---+---+---+ \| | | | | |
| T1 |----+----+----+ | | \
| 2N4403 /| | | | 1K
| c | | T3 | R8
| | 2N4401 c |IRFU220N| /
| | |/ | ||-+ |
| +------+-------| T2 +-----||<- |
| SW1 | | |\ | ||-+ |
| |o \ e /---/ | |
| RST-+ 10K | / \ 20V | |
| |o R7 | --- D3 | |
| | / | | | D4 |
| | | | | | 1N4001 |
| +------+---------+--------+--------+---|<|---+
| |
| |
+-----------------------------------------------+

The LMV431 is a precision programmable zener that is set to trip the
T1-T2 latch and turn T3 off when Vbatt reaches 13.8V (set RP=740 ohms)-
the circuit then goes into trickle charge mode with the array providing
current through R8- battery drain with dark array is negligible, and no
heatsinks necessary




Every night, T1, T2 will be reset by the lack of light and the circuit
will flip back into the fast charge mode.

[...]
increases, T1-T2 remain off if Vbatt<13.8 so that T3 turns on at ~3V
array volts but overall bias across D2 is <0 so that charging does not
begin until array output exceeds ~12.5V or more precisely Vbatt+0.5V. If
Vbatt>13.8V as array comes back on line, T1-T2 is tripped on before
charging begins.

This is the part I see as a problem if the battery is a sealed lead acid
type. I don't have the numbers infront of me. The boost voltage needs to
be applied to a discharged battery to bring it up to charged quickly.
This voltage is 14.something In your case, this is the point where you
want to switch over to using R8.

Once you've done this, you are supposed to stay at the float voltage. The
float voltage is 13.something. If you pop back up to the boost voltage,
you tend to run the battery out of water.


--
--
kensmith@rahul.net forging knowledge

 

[Fred Bloggs]

Ken Smith wrote:

In article <405F0741.8030008@nospam.com>,
Fred Bloggs <nospam@nospam.com> wrote:


Ken Smith wrote:

In article <405EF3EF.6070701@nospam.com>,
Fred Bloggs <nospam@nospam.com> wrote:


One inexpensive way to get a precision cutoff is like so- maybe $5 worth
of components- this has no reverse battery or failsafe overvoltage
protection:
Please view in a fixed-width font such as Courier.


+---------------------------------------------------------+
| |
| |
| +------+----+----------+---------------------+
| | | | | |
| \ \ | | |
| 4.7K 3.3K |C1 | |
| R1 R2 === | |
| / / |0.47U \ 12V
| | | | 47K -----
| | +----+ R3 ---
SOLAR | ARRAY | | / RP _ R4 BATT
+---+---+---+---+ | | | 1K /| 3.9K |
| | | | | | | D1 +-/\/\---/\/\----+----+
| | | | | | | 1N4148 | / | |
+---+---+---+---+ | +-------|>|----|<|---------------+ |
| | | | | | | | LMV431 |
| | | | | | \ \ U1 +---------+
+---+---+---+---+ | 39K 1.2K | |
| | | | | | R5 R6 1N5822 | |
| | | | | | / / D2 --- |
+---+---+---+---+ | | | \ / |
| | | | | +-------------------------+ --- |
| | | | | e | | | | |
+---+---+---+---+ \| | | | | |
| T1 |----+----+----+ | | \
| 2N4403 /| | | | 1K
| c | | T3 | R8
| | 2N4401 c |IRFU220N| /
| | |/ | ||-+ |
| +------+-------| T2 +-----||<- |
| SW1 | | |\ | ||-+ |
| |o \ e /---/ | |
| RST-+ 10K | / \ 20V | |
| |o R7 | --- D3 | |
| | / | | | D4 |
| | | | | | 1N4001 |
| +------+---------+--------+--------+---|<|---+
| |
| |
+-----------------------------------------------+

The LMV431 is a precision programmable zener that is set to trip the
T1-T2 latch and turn T3 off when Vbatt reaches 13.8V (set RP=740 ohms)-
the circuit then goes into trickle charge mode with the array providing
current through R8- battery drain with dark array is negligible, and no
heatsinks necessary




Every night, T1, T2 will be reset by the lack of light and the circuit
will flip back into the fast charge mode.

[...]

increases, T1-T2 remain off if Vbatt<13.8 so that T3 turns on at ~3V
array volts but overall bias across D2 is <0 so that charging does not
begin until array output exceeds ~12.5V or more precisely Vbatt+0.5V. If
Vbatt>13.8V as array comes back on line, T1-T2 is tripped on before
charging begins.


This is the part I see as a problem if the battery is a sealed lead acid
type. I don't have the numbers infront of me. The boost voltage needs to
be applied to a discharged battery to bring it up to charged quickly.
This voltage is 14.something In your case, this is the point where you
want to switch over to using R8.

Once you've done this, you are supposed to stay at the float voltage. The
float voltage is 13.something. If you pop back up to the boost voltage,
you tend to run the battery out of water.

Well- heck, if you're going to do a chemical analysis of the battery,
then simple tapered-current charging is out- you need to go to a
processor with A/D etc...

 

[Fred Bloggs]

Ken Smith wrote:

This is the part I see as a problem if the battery is a sealed lead acid
type. I don't have the numbers infront of me. The boost voltage needs to
be applied to a discharged battery to bring it up to charged quickly.
This voltage is 14.something In your case, this is the point where you
want to switch over to using R8.

Once you've done this, you are supposed to stay at the float voltage. The
float voltage is 13.something. If you pop back up to the boost voltage,
you tend to run the battery out of water.

After looking at some of the SLA charging literature, this solar array
gizmo is limited to trickle charge mode- it does not have the capacity
to fast charge a reasonably sized SLA, and there is no reason to
regulate at float charge when the trickle re-charge is done at 12 hour
intervals. The float charge level at 25oC is 2.3V/cell with -2mV/oC
tempco- this state of charge is supposed to mean 100% capacity- so
whatever the application, the SLA A-H must be sized so that worst case
discharge can be re-charged by worst case trickle charge profile. A
modified charger that does this is this- R8 adjusted to compensate for
estimated bias drain only- and charge status LED glitz added:
Please view in a fixed-width font such as Courier.


+---------------------------------------------------------+
| |
| |
| +------+----+--------------------------------+
| | | | |
| | \ | +-------|<|-----------+
| | 3.3K |C1 | 1N4148 |
| | R2 === | D4 |
| | / |0.47U \ 12V
| | | | 47K (adj for 13.8V) -----
| | +----+ R3 (at 25oC ) ---
SOLAR | ARRAY | | / RP _ R4 BATT
+---+---+---+---+ | | | 1K /| 4.7K |
| | | | | | | D1 +-/\/\---/\/\----+----+
| | | | | | | 1N4148 | / | |
+---+---+---+---+ | +-------|>|----|<|---------------+ |
| | | | | | | | LMV431 |
| | | | | | \ \ U1 |
+---+---+---+---+ | 33K 1.2K |
| | | | | | R5 R6 |
| | | | | | / / |
+---+---+---+---+ | | | \ 330 |
| | | | | +-----------------|<|---/\/\-------+ |
| | | | | | | | \ R9 | |
+---+---+---+---+ | | | 9V --- |
| \ | | ZENER D6\ / ~~ |
| 4.7K | | D5 --- |
| R1 | | |CHRG |
| / | | |LED |
| | | | | |
| +-------------------------+ | 1N5822 |
| e | | | +--|<|----+
| \| | | | | D2 |
| T1 |----+----+----+ | | |
| 2N4403 /| | | | |
| c | | T3 | |
| | 2N4401 c |IRFU220N| |
| | |/ | ||-+ |
| +------+-------| T2 +-----||<- \
| SW1 | | |\ | ||-+ 3.3K
| |o \ e /---/ | R8
| RST-+ 10K | / \ 20V | /
| |o R7 | --- D3 | |
| | / | | | |
| | | | | | 1N4148 |
| +------+---------+--------+--------+--|<|----+
| | D7
| |
+-----------------------------------------------+

 

[Ken Smith]

In article <406304BE.20809@nospam.com>, Fred Bloggs <nospam@nospam.com> wrote:

[...]
After looking at some of the SLA charging literature, this solar array
gizmo is limited to trickle charge mode- it does not have the capacity
to fast charge a reasonably sized SLA,

It depends on what you call reasonable. A 1AH 12V battery is something
that would go in a handheld.

Please view in a fixed-width font such as Courier.

I like the idea of the LED. I've long though that it is too bad they
don't make LCD pilot lights. A little 2 wire thing could change color
when DC is applied to it. It would draw way less than an LED.

--
--
kensmith@rahul.net forging knowledge