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Solar Panel + LCR6V4P Sealed Lead Acid battery Charging....

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ikelectro

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I have solar panel 6V 3W and a Sealed Lead Acid battery of 6V, 4Ah/20HR..

I want to charge the battery with my solar panel (it gives 500mA at 6V). But the battery need the charge as 200mA upto 20Hrs...

Here is he problem:
I never worked with battery charging before.:confused: how should I proceed now....

As i googled about the charging method of Lead Acid Batteries, found that Constant Voltage
Chargers
may be a good option....

So now need some expertise advise.... :)
 
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If 6V is the maximum output voltage of the panel it won't be enough to charge the battery fully.
 
the panel labeled as 6V and 3W. but when I have been working in bread board the multimeter showing around 9.4V (fluctuating with the sun light)......


and plz see the picture that i added...... DSC04904.JPG
 
I never worked with battery charging before. how should I proceed now....
Check out batteryuniversity.com for advice.
 
...
I never worked with battery charging before.:confused: how should I proceed now....

As i googled about the charging method of Lead Acid Batteries, found that Constant Voltage
Chargers
may be a good option....

Here is a previous thread that deals with this topic.
 
I have gone through the previous post. now let us assume that with the solar panel I can get 7.2V out put (assume

more that i use a voltage stepper circuit and LM317 to get that.) Now I am wondering how I can get a costant

200mA source with that ( as my Solar Panel stated as 3W).... can a current limiting resistor will do that????
 
The battery voltage changes as it charges. If you use a constant voltage charger then a series resistor will give a charging current which tails off as the battery approaches full charge; i.e. it is not a constant current. Do you mean a 200mA current limit?
 
the panel labeled as 6V and 3W. but when I have been working in bread board the multimeter showing around 9.4V (fluctuating with the sun light)......


and plz see the picture that i added...... View attachment 74005


hi
The maximum power point of 3Watts is the product of Vmpp and the current at Vmpp.

This means, from the label, 3W/8.3V = ~350mA.

So at solar energy of 1000W/m^2 it will deliver 350mA at 8.3V, at lower solar light energy it will be a lower wattage.

E.


EDIT:
Have you considered a simple shunt regulator.?
 
Do you mean a 200mA current limit?

Yes. As the battery requires the charge rate 200mA ( as i understand by following the battery).
 
Have you considered a simple shunt regulator.?

Hi,
as the situation has became still now, I'm not at the position to decide anything yet. I want to do the best possible act as far as my capability....
 
Hi,
as the situation has became still now, I'm not at the position to decide anything yet. I want to do the best possible act as far as my capability....

hi,
Does your panel have an internal diode on the positive output terminal.?

Its used to prevent a reverse current flowing back into the panel from an external battery source.

If you need help with a shunt regulator let us know.
 
As Eric pointed out, the panel is rated to put out a max current of ~360mA at 8.3V.

It will put out slightly more current (~400mA) if connected directly to the battery with no intervening regulator.

This Sealed lead acid battery will take a max charge rate of 1.35A, so no current limiter is needed; the panel cannot exceed the max allowed charge rate.

It can, however, exceed the maximum allowed charging voltage of 7.2V, so a voltage regulator is required. You also must switch the regulator output voltage from 7.2V to 6.8V after the charging current drops to a low level per the previous forum thread.
 
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Hi ericgibbs....

Does your panel have an internal diode on the positive output terminal.?

No. At the time of breadboarding I have used a 1N4007 on the positive terminal (it will be better if i used a 1N5817 ?).

If you need help with a shunt regulator let us know.

Actually I'm just familiar with the word of SHUNT REGULATOR... never get the chance (or i should say need?) to work with shunt regulator.....:eek::eek::eek::eek:
 
Hi MikeML .... I think this picture can have more details about the battery I want to use.......DSC04905.JPG

This Sealed lead acid battery will take a max charge rate of 1.35A, so no current limiter is needed; the panel cannot exceed the max allowed charge rate.

So in this battery(the picture I added), I don't need a current limiting res????


You also must switch the regulator output voltage from 7.2V to 6.8V after the charging current drops to a low level per the previous forum thread.

I think my knowledge in electronics can make some difficulty to do that.......:eek::eek::eek:
 
...So in this battery(the picture I added), I don't need a current limiting res????
As I said: "This Sealed lead acid battery will take a max charge rate of 1.35A, so no current limiter is needed; the panel cannot exceed the max allowed charge rate."
I think my knowledge in electronics can make some difficulty to do that.......:eek::eek::eek:
Then purchase a solar charger ready made.

You could also just build a voltage regulator that is preset to 7.2V. In that case you will have to monitor the current flowing into the battery using a dedicated meter. Watch the charging current. When it drops to <20mA, disconnect the battery from the charger (a lot of work). If you screw up and leave the charger connected too long, you will be degrading the battery by overcharging it.

Or just set the voltage regulator to 6.8V. This will still charge the battery to ~90% of full charge, but it will take five to ten times as long as it would have taken if the charge voltage was set to 7.2V.
 
Here's a simple possibility (not optimised for maximum energy extraction from the panel):-
SLA_Charger.gif
 
Because the OP specified a 200mA limit. If the battery chosen can handle all the current the panel can throw at it then no, it's not needed.
 
I don't know where the 200mA limit came from. The battery that the OP linked to will tolerate a charge rate of 1.35A (It is printed right on the battery).
 
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