Hi, I am building a solar and hydro powered water meter. Do you have any ideas on how to isolate the two sources, where only the one with the higher voltage will work? I will greatly appreciate your help. Thank you!

 

" a solar and hydro powered water meter"!!! ..... What's that ???

You wan't "only the one with the higher voltage to work" ... that seems a bit wasteful , the plan must be to extract energy from both sources it , should be possible....

Give lots more details ....

 

oh, I didn't know that was possible. It's because I was told that if they both work together, the output voltage may be averaged. My solar panel has an 11v max output voltage while the water turbine generator has a max output of 12v. I am going to use this to charge a 3.7 lithium ion battery.

 

For safety's sake, buy a ready-made lithium battery charger which will accept the maximum input voltage from either source.
The two sources could be coupled to the charger input via respective diodes. This arrangement forms an 'OR' gate which allows the higher voltage source to drive the charger.

 

Hi,

Did you use the word meter incorrectly? Do you mean charger.

I'm pretty sure if you connect them both in serial, you will get better results.

As mentioned be careful about charging lithium batteries.

Give some power information amps/watts

Camerart.

 

For safety's sake, buy a ready-made lithium battery charger which will accept the maximum input voltage from either source.
The two sources could be coupled to the charger input via respective diodes. This arrangement forms an 'OR' gate which allows the higher voltage source to drive the charger.

This is the answer. It's very common to "OR" power sources together and all you need are diodes to protect each source from current being driven backwards through them by the other source. Given your low voltages, I recommend Schottky diodes (ex. SB540) because they will show a lower voltage (and thus power) drop across themselves.

Don't bother designing your own charge controller - use a ready-made one as recommended.

 

If 11 v is the max. solar, then rated V will be around 8 V which contribute little in charging.
Li charger input V might be around 5 V so a buck converter might be needed.
What are the power levels of the two sources?

 

If 11 v is the max. solar, then rated V will be around 8 V which contribute little in charging.
Li charger input V might be around 5 V so a buck converter might be needed.
What are the power levels of the two sources?

Hi, my solar panel is 5.5V 200ma. We have 2 that we connected in series. And it is able to give around 10+ volts. Then I used a buck boost converter to give a 5v output. But it was not able to charge the lithium ion battery that is connected to a powerbank module. Is the current a problem here?

 

This is the answer. It's very common to "OR" power sources together and all you need are diodes to protect each source from current being driven backwards through them by the other source. Given your low voltages, I recommend Schottky diodes (ex. SB540) because they will show a lower voltage (and thus power) drop across themselves.

Don't bother designing your own charge controller - use a ready-made one as recommended.

Thank you!

 

For safety's sake, buy a ready-made lithium battery charger which will accept the maximum input voltage from either source.
The two sources could be coupled to the charger input via respective diodes. This arrangement forms an 'OR' gate which allows the higher voltage source to drive the charger.

Hi, my solar panel is 5.5V 200ma. We have 2 that we connected in series. And it is able to give around 10+ volts. Then I used a buck boost converter to give a 5v output. But it was not able to charge the lithium ion battery that is connected to a powerbank module. Is the current a problem here?