Battery Charging

[reishigupta]

Hi, I am new to the forum.

Straight to question:

Material I have: Two Batteries each 200Apms 12 Volts

Solar PV as follows:

200W 24 Volts 6 Amps

250W 24 Volts 7 Amps

230W 24 Volts 7 Amps

Inverter Input 24 Volts from solar to 12 V output to battery.

 

Questions I have:

1. Amps written on the Solar PV as 6 or 7 amps are 6 amps/hr? Or does it means something else?

2. How many hours will my solar panels take to charge my two batteries? (I understand that there is a solar charge controller in between to control) If you can give the calculation, I would really appreciate.

3. What is required to charge battery - voltage or Amps or both? Is it correct to say that to charge my 12V 200 Amp battery, I would need to charge it with 12V 20amps for 10 hours?

3. Is 24V 7amp = 12V 14 amp?

 

Please help me in getting answers to these.

 

Thank you,

Rishi

Edited July 25, 2013 by reishigupta

[EdEarl]

1. PV amps is typical max output, not per hour. If the PV gets enough sun for an hour it can output max for an hour or more. But, clouds and the incidence angle of light affects output.

 

3. Volts must be enough, but not too much. Current flows into the battery to charge it.

3. 12V not = 24V and 14A not = 7A. But 12V*14A=168W=24V*7A

 

2. Charge time will vary, depending on charge remaining in you batteries and the amount of light hitting the PV cells. Moreover, you have not given the inverter rated output amps. Even if the inverter is able to output >14A @12V, there are resistance losses which means your actual output can not be 14A @ 12V.

 

If the inverter does not have an output specifically for charging batteries, it may damage batteries by over charging them.

 

Charging time can be calculated as A-h / A.

[Externet]

Hello.

 

1. Amps written on the Solar PV as 6 or 7 amps are 6 amps/hr? Or does it means something else?

 

It is 7 Amperes. If delivers energy during 4 hours, will be 7x4=28 Ampereshour

 

2. How many hours will my solar panels take to charge my two batteries? (I understand that there is a solar charge controller in between to control) If you can give the calculation, I would really appreciate.

 

From a halfway charged state, say 2 batteries at a point capable of only 100 Amperes each;

At 7+7+6= 20 Amperes, should take 200/20=10 hours. At full sun. Not a precise answer but should help you.

 

3. What is required to charge battery - voltage or Amps or both? Is it correct to say that to charge my 12V 200 Amp battery, I would need to charge it with 12V 20amps for 10 hours?

 

A single 12V battery should receive more volts applied to it than its current charge state, limited to 14 V for charging (28V for two)

 

3. Is 24V 7amp = 12V 14 amp?

Yes, you can say that

 

There is a few possible configurations for the items you have. The one I would chose would be as picture attached next.

will supply 24V at 200 Amperes capability.

 

 

Unless there is an error in the 'inverter' specifications being really 24VDC in and 120VAC out; I see no need for it applying the schematic above.

If it really is 24VDC in and 120VAC out, just connect it to the bottom arrows in proper polarity.

 

=======================================================================

 

Second way, attached below.. This will supply 12V at 400 Amperes capability, and uses your converter.

 

Edited July 25, 2013 by Externet