Calculation for recharging time!

[Sunking]

A flashing light so it has about a 20 to 30% duty cycle.

Well OK but there is a difference in my mind between a Flash light, and Flashing Light.

Will work for 24 hours,but I dont' have led specification,only know is a flash light!

Language translation issue.

[Wy_White_Wolf]

Well you had better find out, otherwise you are likely in for a nasty surprise. For example if the LED is say 2 watts x 24 hours = 48 watt hours. That 4 watt panel and 10 AH battery is not going to work. Well it will for about a day or two, then dead after that.

A flashing light so it has about a 20 to 30% duty cycle. Propably 10 to 15 Wh daily. In most locations though the panel would have a hard time keeping up with that in the winter.

WWW

[Sunking]

Will work for 24 hours,but I dont' have led specification,only know is a flash light!

Well you had better find out, otherwise you are likely in for a nasty surprise. For example if the LED is say 2 watts x 24 hours = 48 watt hours. That 4 watt panel and 10 AH battery is not going to work. Well it will for about a day or two, then dead after that.

[albert436]

Ineteresting.

product_solar_powered_p03.jpg

[paulwater]

How many hours a day will that light actually be on and how many watts is it rated for?

That information will help determine the number of watt hours the light will be on each day and help determine how many days the battery will actually light it.

Nice little experiment you have there.

Hello
Will work for 24 hours,but I dont' have led specification,only know is a flash light!
show you the link

http://www.zhan-yi.tw/products/categories.php?cid=5&language=_eng

Yes,I like experiment!haha~It's for my concept design!

Thanks!

[SunEagle]

This is solar traffic light from china!
company say can work for seven days in cloudy condition!

the solar panel specification
Pmax 4.3W
Voc 9.6V
Vmp 8.0V
Isc 0.59A
Imp 0.54A

Battery
6V,10Ah

How many hours a day will that light actually be on and how many watts is it rated for?

That information will help determine the number of watt hours the light will be on each day and help determine how many days the battery will actually light it.

Nice little experiment you have there.

[paulwater]

Check the device!

This is solar traffic light from china!
company say can work for seven days in cloudy condition!

the solar panel specification
Pmax 4.3W
Voc 9.6V
Vmp 8.0V
Isc 0.59A
Imp 0.54A

Battery
6V,10Ah

[paulwater]

Efficiency Factor is 1 or less so yes 100% = 1
FLA = Flooded Lead Acid
SOC = State of Charge

Thank you for explain me!

[paulwater]

20 to 50% of your battery would be 12 to 30Wh. You don't want to use any more than that or you will damage the battery.

1.5 is to compensate for system losses. That is about what a PWM charge controller system would lose. Your system is too small for an MPPT controller.

WWW

Ok!
Thank you so much!haha
I will show the device later!

[Sunking]

About your answer I almost got it,there few words I can't understand!
Efficiency correction fact less 1? Is means 1=100%?
What is FLA,SOC?

Thank you!

Efficiency Factor is 1 or less so yes 100% = 1
FLA = Flooded Lead Acid
SOC = State of Charge

[Wy_White_Wolf]

Hello Wolf
Thank you for the answer,and would you mind explain me a little more?haha
I don't understand "run on the top 20 to 50% of the battery" ,is mean use 20% and 50% panel efficiency to recharge battery?
And what is 1.5?

Thank you!

20 to 50% of your battery would be 12 to 30Wh. You don't want to use any more than that or you will damage the battery.

1.5 is to compensate for system losses. That is about what a PWM charge controller system would lose. Your system is too small for an MPPT controller.

WWW

[paulwater]

Is 7 days quick enough for you PW?

It's ok!haha
Thanks!

[paulwater]

Well for one that 4.3 watt panel will not deliver 4.3 watts. YOu have two efficiency issues:

1. Is the losses of the wiring and charge controller you have to account for.
2. Battery charge efficiency. I assume this is a Flooded LEad Acid Battery? if so 80%

A good rule of thumb is:

H = AH / A / C

Where H = Hours
A = Amps
C = Efficiency correction fact less 1

So assuming this is a PWM controller using a 4.3 watt 6 volt panel A = .5 amps, and C = .8 for FLA then:

H = [10 AH / .5 A / .8 = 25 Hours

Assuming a 4 Sun Hour Day it will take a full week or 7 days to recharge from 0% SOC

Hello Sunking
I will calculate with two issues,thank you!And you were right,that battery is lead acid battery!Take it from solar traffic light!
I'll show the pic later!

About your answer I almost got it,there few words I can't understand!
Efficiency correction fact less 1? Is means 1=100%?
What is FLA,SOC?

Thank you!

[paulwater]

Correct format and units:

60Wh/4.3W = 13.9h

Actually you only want to run on the top 20 to 50% of the battery and also have to add in for losses.

50%:
60Wh / 4.3W * .5 * 1.5 = 10.5h

20%:
60Wh / 4.3W * .2 * 1.5 = 4.2h

So you recharge times should be between 4.2 and 10.5 hours or typically 1 to 2.5 days at 4 hours average insolation.

WWW

Hello Wolf
Thank you for the answer,and would you mind explain me a little more?haha
I don't understand "run on the top 20 to 50% of the battery" ,is mean use 20% and 50% panel efficiency to recharge battery?
And what is 1.5?

Thank you!

[paulwater]

http://www.csgnetwork.com/batterychgcalc.html

Just googled the title of your thread, something about "efficiency loss" might need to be figured in. (?)

Thank you for the Link!
I'll try it!