How to Add LED Charge Indicator for Solar Panel Output vs Load Consumption (Motor, VSC)

I was hoping if any of you fellows in the engineering department could help me with a question so here it goes.  I want to add a charging indicator (small LED light) that turns on when more current is being produced from a solar panel vs the amount of energy being used by a load such as a motor with a variable speed controller.  In such case, you would therefore be able to monitor and control the speed of the motor so that it doesn't consume more power than what the solar panel is producing which in turn allows the user to sustain a charge on a battery source.  Ive used amp and volt meters to monitor such a system, however I would like it basic so that the only indicator is an LED.  Any insight or basic schematics would be of great service. 

Kind Regards,

Dave Paulson

 

 

  

Some questions before we look at possible answers.
1) The Battery must be trickle charged to full capacity at all times while the Solar panel has enough power to do so?
2) The motor takes power only from the solar cell when the demand of the battery charging is lower than the total output of the solar cell, motor speed is not critical?

If I get your drift right then you will need to monitor the battery for charging rate (different for each type of re-chargable battery) and adjust the current going to the motor if spare power is available.

Solar panel out put is direct current or alternating current? I suspect in your case this is DC. in which case your available current will be determined by some form of shunt or Hall effect current monitor.

All of this is doable with Arduino type micro and Arduino modules available from the internet.

Regards
Conrad aka Crusty

Thanks for your reply:

To answer your questions..

1) Trickle charge is not necessary yet the preferred. A 20 amp motor at full speed will draw 20 amps for example, and the solar panel at peak sun can only produce 6 amps. If I had the ability to dial down the speed of the dc motor to 5.5 amps (if my desire was to maintain a charge on the battery from solar) then I would like to know that simply put.. A LED indicator would illustrate more power is coming in than going out. If it was cloudy and only 3 amps was being produced by the sun, then I could dial the speed of the motor to 2.5 amps for example and then the light would turn on. This way there is no draw from the battery, however if I desired to run at full speed and drain the battery I as well could just as easily, yet I would know by a simple LED indicator as to when I am not drawing from the battery.... I hope this helps.

2) you guessed it, motor speed is not critical.

Both systems are DC current, as stated in original post, I have used voltage and amp meters to indicate charging amps from solar as well as the load amps from motors. The meters used shunts. I would like to simplify the display so that a simple LED light turns on when a charge is going to the battery once motor load is less than output of solar panel. Any further insight would be of great value.

Thanks again,

Dave Paulson

Hi Moccassin Kayaks, LLC,

set the charging current limit to 1/10 of the bat ah and provide an led and a resistor
parallel to the current limit resistor. Anode of led should go to the charge voltage input
and cathode to bat positive now when more current is drawn by the bat the led starts
glowing ,use 1k,2k2, or 10k resistor for the led as per your indication of the current
equirement mostly 10k will be ideal for the led.