Hi, Hope this is the right place, Im struggling to get answers on my project.

First a bit of background on what im trying to accomplish.

I recently bought a Gizzu 300w power station. It has a dc input of 18v 3A to charge (Solar & DC Same Port), takes about 6.5h, but I can reduce that to 3.5h if I add a PD quick charge to it.
 

• Charging Times:
  • AC Adapter: 18V/3A (6.5hrs)
  • DC Solar Panel: 60W (6.5hrs)
  • PD Port: 45W (7.5hrs)
  • PD Input/Output: 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/2.25A
  • AC Adapter + PD Port: 18V/3A + 45W (3.5hrs)

My Laptop also charges via PD @ 45w and uses the 20v, so I assume this power station also uses 20v/2.25a?
(I dont have a USBC power measuring tool, so not sure what the power station charges with via PD)

The power station supports charging via a 60w solar panel (same input as the AC charger, comes with a charging brick). I dont just wand to get one 60w, but take it a step further, I want to get a big enough solar panel to support both the 18v 3a input as well as the PD charge input together.

Theoretically I need to get the following:?

160w 21v 10a solar panel (pd power needs a 20v output and this gives 21v) to power the following 2 x "chargers";

1. Step down buck converter to convert the 24v to: 18v 3a to charge my power station.

2. I got this board, not sure if I made a mistake; SparkFun Power Delivery Board - USB-C (Qwiic) (Only USBC Quick charging board available in this country, ordering from AliExpress takes months to get here);

I see it needs a 20v input, so I want to use another step down converter to convert the 24v to 20v to power the Sparkfun board to charge my power station or laptop with, or can I just attach a USBc cable to the step down converter and use it directly to charge?

Another option for PD Charge is a bit more bulky, but I can get a 200/300w car charger inverter to AC and power a AC charging brick?

What other options is there to Charge a USBC PD Device, I want to be able to charge my Laptop / Power Bank / Power station with solar.

I also need to know if it will be necessary to get a solar charge controller before all these electronics, or can I power the Buck converters directly from the raw solar panel feed?

11 hours ago, Hardusb said:

). I dont just wand to get one 60w, but take it a step further, I want to get a big enough solar panel to support both the 18v 3a input as well as the PD charge input together.

You might be limited by how much power the port can take. A quick google seems like the DC input can only support 12V 5A (60W) anything more it will heat up and melt.

 

I am not sure I understand your aim

You get a PD capable supply, it starts with a standard 5V output 

If you plug in a PD capable device, it requests the supply to up the voltage to 5V, 9V, 12V and 20V via communication protocol. 

The sparkfun module you purchased is a device side negotiator to request the desired voltage from the supply 

 

HI, thats why I will use a Buck converter to get the voltage and amps just right. The AC Adaptor that came with it is 18V 3A, the specs says you need a 18V 60W Solar panel.

My aim is to go one step further and get a big enough Solar panel so that I can charge the USB PD also via the Solar. If I get a solar panel for USB C PD Charging it will be enough to charger the other input also via a Buck Converter, you can set the Voltage and amps with it..

I also think I made a mistake with the Sparkfun Module. You get much cheaper USBC trigger boards that will do the same as it.

My alternate option for the USB PD is a Car charger:
https://snatcher.co.za/wk-wp-c31-flash-series-65w-usb-usb-c-type-c-interface-fast-charging-car-charger-blue/

https://africadroneking.co.za/product/dji-65w-usb-car-charger-for-mavic-3/
https://baseus.co.za/product/baseus-5a-65w-qcpps-digital-display-usb-ca-quick-car-charger-cable/

https://www.firstshop.co.za/products/hp-65w-usb-c-auto-adapter-5tq76aa-133673

 

Most is out of stock.

OK so

Solar panel -> solar charge controller connected to its own battery -> connected to load output on controller -> 12-24V USB PD -> usb cable -> laptop charged with PD

                                                                                                                                                                                      -> buck/boost controller to charge "gizzu power station"

 

https://the4x4store.co.za/products/12v-24v-type-c-pd-blueled-voltmeter-qc3-0-usb-car-charger      (I have not checked if the store is legit)

 

Not sure if a solar charge controller will give an output without a battery connected

8 minutes ago, iiznh said:

OK so

Solar panel -> solar charge controller connected to its own battery -> connected to load output on controller -> 12-24V USB PD -> usb cable -> laptop charged with PD

                                                                                                                                                                                      -> buck/boost controller to charge "gizzu power station"

 

https://the4x4store.co.za/products/12v-24v-type-c-pd-blueled-voltmeter-qc3-0-usb-car-charger      (I have not checked if the store is legit)

 

Not sure if a solar charge controller will give an output without a battery connected

I don't think a solar charge controller will be neccecary, don't need a battery, need a semi portable setup.

That charger you linked to is 40w max, I need a 65w one I can charge my PD powerbanks if needed, they do seem to have a 60w one:

https://the4x4store.co.za/products/dual-qc4-0-type-c-and-qc3-0-usb-charger

It says 65w but in the description it says thw following which is a bit contradicting:

Output current	QC3.0(5V/3A 9V/2A 12V/1.5A)
Output voltage	5V
USB type-C port output	QC4.0(5-20V,max:60W)

I'll chat them up to see if they can verify the specs for me. 60w looks like the best I'll be able to get.

 

A full solar setup with a battery is going to be too expensive now, for now just need to be able to charge the gizzu / laptop / power banks

A solar panel will work fine as long as you draw from the power curve where the voltage is high (which is dependent on the amount of light). The moment the power draw is too much the voltage will fall. That said you will probably struggle in cloudy conditions. A charge controller provides a (semi)constant voltage (with the help of a battery) but variable current. You could probably get away with a small 12V battery used in gate motors. PWM charge controllers are fairly cheap especially if you buy a small one with 20A output

2 hours ago, iiznh said:

A solar panel will work fine as long as you draw from the power curve where the voltage is high (which is dependent on the amount of light). The moment the power draw is too much the voltage will fall. That said you will probably struggle in cloudy conditions. A charge controller provides a (semi)constant voltage (with the help of a battery) but variable current. You could probably get away with a small 12V battery used in gate motors. PWM charge controllers are fairly cheap especially if you buy a small one with 20A output

HI,

I understand the solar panels dont work with Cloudy conditions, for the time being its just going to be an Emergency power supply for my power station and or Laptop. To reduce the Amps in I can just use a Resistor on the Solar panel side to reduce the solar amps out?

Regarding the gate motor batteries, I need 18/20v out, they only 12v, so I will then need 2 in series? I have 3 spares in good condition here.

I dont understand what you mean by this: "as long as you draw from the power curve where the voltage is high".

I also noticed theres these specs:

Optimum Operating Voltage (Vmp): 18.21V.

Optimum Operating Current (Imp): 8.79A.

Open-Circuit Voltage (Voc): 22.39V.

Short-Circuit Current (Isc): 9.529A.

I assume I need to work with the "Optimum Operating Voltage". 

As I need a 20v output for my PD Charging, I will most probably need a Solar panel with an Higher than 20v Optimum Voltage? Or can I use a Buch Boost controller to boost the volts from the 160w panel to get my 20v? Theres plenty of spare amps, I will need a max of 6A between the 2 outputs?

Im looking to get the following Buck converters: https://www.mantech.co.za/ProductInfo.aspx?Item=15M3540-A Its for a fixed 3A output with a variable voltage. I should be able to boost from 18.21V - 20v with this one? And https://www.mantech.co.za/ProductInfo.aspx?Item=14M2243 Down to 18v 3A to the other?

Solar Panel Output 18.21v: (Not sure if I need a resistor also to limit the current to the converters)

* Output 1: Buck Boost Converter --->20V 3A ---> USB PD Charger

* Output 2: Buck Step Down Converter --->18V 3A ---> Power Station

The USB PD Charger says it can take from 12-24v in, so Im just going to use the buck boost converter to limit the current to 3A, dont think the charger will take good with a full 10A input?

Edited November 15, 20223 yr by Hardusb

22 hours ago, Hardusb said:

I dont understand what you mean by this: "as long as you draw from the power curve where the voltage is high".

Look at the voltage current curves of a panel

To express it in a better way, you need to draw little enough current to avoid the voltage to dip (which is what a PWM charge controller does). I would get a 20A PWM charger because you might just find the next thing you would like to charge too, they are like R250 ballpark. That should allow you to use the panel most hours and even in cloudy and rainy weather

The PWM charge controller gives you a constant voltage with a variable current, paired with a battery as buffer you should be able to run your setup with your batteries in parrallel and charge them with 14.4V and float them with 13.8V. The currents are small enough that 12V will work for your application

Use the load output on the charge controller to connect the DC/DC boost converter to charge your "power station" with 18V3A and use a standard 12V car usb charger with PD that should be able to power your laptop. Also worth to note that your laptop will only pull 65W when recharging the battery, most laptops draw 10-15W with day-to-day work so a smaller than 65W should be fine 

And no a resistor will not work, it will act as a voltage divider, consume energy and heat up

Thanks for the advice. I watched this one YouTube video where the guy puts a 300w buck boost converter between the solar panel and the pwm controller, says its a cheaper way to get the same effect as a MPPT Controller, The max I would draw from the panel would be about 6A, it supplies 10A. Will the 160W work or must I get a bigger one?

Which Model controller do you suggest? Hows the Ecco ones the Chinas sell? Any good?

I saw the attached one at a Solar shop for R1700.

2 hours ago, Hardusb said:

Will the 160W work or must I get a bigger one?

Which Model controller do you suggest? Hows the Ecco ones the Chinas sell? Any good?

Personally I would rather look for a 330W or similar panel. Many more watts for the same money. That way you will have almost enough current even on rainy days

Sorry link I provided was to sold out panels.... seems like loadshedding killed all stock

Personally I prefer to stick to well known brands like JA/Canadian Solar

 

A 10A panel will yield 10A on perfect conditions, most days you will see 8A (between 11 and 2), early mornings you will get anything between 1A-6A

My dad runs an ecco controller in his setup, they do work fairly well. F

or a budget application they are perfect, they waste some energy (like every other PWM) but they are cheap and sometimes that is more important.

 

 

 

 

Edited November 16, 20223 yr by iiznh

Hey @Hardusb, 

I came across your thread, and while it’s a bit old, I hope it’s alright to ask for some advice. I’m currently facing a similar issue.

I recently bought a 300W Gizzu power station along with their 100W solar panel, but I’m finding that it charges quite slowly. I’m considering using the USB-C port for charging as well.

Would you recommend an mppt controller or going with the buck converter? Please assist. 

Hope you're doing well! I’d really appreciate any guidance you can offer. Thanks so much!