Help with DC / DC boost controller chip

[Mr.K]

Hello there.

I have got a DC/DC boost controller chip with below specifications :

On-board ultra-small PFM controlled DC / DC boost controller chip

2-any input 0.9V ~ 5V DC voltage output 5V DC voltage can be stable, with two AA batteries input to output 500 ~ 600MA current single AA battery output current 200ma about for mobile phones, camera, single-chip, digital products supply. Can be stable output voltage 5V DC

3-onboard USB female seat, can be supplied directly to the USB interface device

4- on-board input voltage indicator

5- PCB size: 34 (mm) x16.2 (mm)

One AA battery is enough to run a 5-volt usb LED light. I tested it and it works fine. But when I connect it to solar panels generating 1.5 to 3.5 volts (solar panel instead of a AA battery) , it doesn't work!!! I checked the voltage of solar panels exposed to light when not wired ; it is 1.5 to 3.5 volts. But when I checked the voltage of solar panels wired to the boost controller ; it is 0.65 volts!

What is happening ?!

Thanks

 

[BobK]

The solar panels cannot produce enough current.

How much current does the light require? If the solar panels under load are 0.65V they would have to produce about 8 times that much current to run the light.

Bob

 

[(*steve*)]

You have discovered the main difference between MPPT and a SMPS.

MPPT will deliver as much power as possible to the load.

An SMPS will drag the input voltage down if the entire damanded power cannot be supplied.

Where there is excess input power, both will work.

If the available power drops then rises again, an SMPS may lock itself into a state where it cannot take advantage of the available input power.

 

[Mr.K]

The solar panels cannot produce enough current.

How much current does the light require? If the solar panels under load are 0.65V they would have to produce about 8 times that much current to run the light.

Bob

But the solar panels are from a solar power bank. My power bank's board was damaged and I want to make one with the same battery and solar panel

 

[Mr.K]

Do I have to wire solar panels parallel or series ?!

In series , the out put voltage is much more

 

[Mr.K]

What Should I do now ?!

I can't afford to buy more powerful panels or chips. Any suggestion ?

What about having 2 AA rechargeable batteries as input to the boost controller and at the same time wire the 2 AA batteries to the solar panels with a 1n4001 diode ?! I mean , solar panel may charge the AA rechargable batteries and provide enough power for boost controller to charge my 6000 Amps lithium battery . Sounds crazy ha ?

 

[(*steve*)]

If you connect your panels to the boost converter with no load connected to the boost converter (and the cells in full sun)...

1. what is the voltage at the input of the boost converter?
2. what is the voltage at the output of the boost converter?

edit: make sure the cells are in full sun BEFORE you connect them to the boost converter.

 

[Mr.K]

I figured it out!
I had to wait some time when solar panels are exposed to the sunlight. It works fine after some time ...

 

[Mr.K]

The most important factor about solar panels is the light. I tried many lighting sources but non of them is as much powerful as the sunlight in outdoor.

 

[(*steve*)]

If you had mentioned you were using anything other than direct sunlight...

Anyway, I'm glad it's working for you now.