So if a power source is capable of providing 12v @ 10W, and if I only wanted 5v from the power source, what's the maximum power I can get?

The Facts. Gave Ohm's law voltage and wattage, and figured the rest out.
12v, 10W, 0.83A, 14.4Ω

So let's say I have in my possession, a CV CC 20A buck converter. I can drop the voltage down to anything lower than 12vdc.

I want 5v.

So the maximum power I can get from 5v is 10 Watts?

So does that mean that I can get 5v, 2A, 10W from the 12v 10W power source?

 

So does that mean that I can get 5v, 2A, 10W from the 12v 10W power source?

Only for a 100% efficient buck converter.
Of course no converter is that efficient, so the actual 5V power available would be somewhat less.

 

You really need to check the spec of the converter. For instance it may have a maximum output current limit of 1A.

 

What is the chip on the converter or what spec is the module?

 

5A Lithium Charger CV CC buck Step down Power Supply Module LED Driver New Z2

1. Input voltage range: 6～38VDC
2. 1.25-36VDC output voltage.
3. Output current: 0 - 5A
4. High efficiency up to 96%
5. Built in thermal shutdown function
6. Seller name: satisfyelectronics

Was getting them to charge 26650 batteries in series. But first I needed to bottom balance the batteries.
It's for a smart light sensing solar charger project I'm working on.

I should get them monday.

So for 5v I'd still only be allowed to get a max of 10W @ 2A ?

I guess.. If a power source can only give MAX 12v @ 10W, then what's the MAX for 5v.. is it 10W still, or does it go up?

 

Hello,

As stated the efficiency is 96 % max.
So you will get max 9.6 Watts @ 5 Volts from the 12 Volts 10 Watts source.

Bertus

 

It says output power 75W, so as long as your power supply is capable of providing what you need you're ok.

 

10W / 12V = 0.833 Amps.
10W / 5V = 2 Amps.
Ohm's Law !!

But that's good and bad.

Because if your solar panel is able to give that 2 Amps at 5V, then that's good.
But if your device requires 5V 10W, then that's bad. Because then you need to give 2 Amps.

So that means more drain on the battery, because the voltage requirement is so low.

If it was 9V requirement @ 10 Watts, then that's 10W / 9V = 1.11 Amps.

5000 mAh battery, 5Ah / 1.11 Amp for 1 hour, 1.11 Ah = 4.504 Hours @ 100% hardware efficiency.

150 Watts (Laptop, Hdd, HDTV) @ 120VAC.

12.6Vdc LiPo battery, 5Ah (5000mAh), 25C.

Ohm's Law (P/E = I)
150 Watts / 12.6V = 11.904 Amps)
11.904 Amps for 1 Hour = 11.904 Ah (11,904 mAh).

5,000 mAh battery / 11,904 mAh load = 0.42 Hours.
0.42 Hours x 60 Minutes = 25.2 minutes.
0.2 Minutes x 60 Seconds = 12 seconds.

25 Minutes : 12 Seconds (100% Max Efficiency)

But my laptop, HDTV, and External HDD doesn't use 150 Watts all the time. Right now it says 94.4 watts, ...

So it's good to say more than 25 minutes, 12 seconds. because again, it doesn't use the MAX wattage all the time.