12 solar water pump running of super cap bank

[bruce_loco]

Hi

I want to use 12v solar water pump to drain water from a well
The battery system i want to use is a 16v capacitor bank with a dc-dc converter to 12v

A 2nd motor 12v motor will be wired to pump that water to a small irrigation system.
Since this is super caps there is no charge controller(except for the regulators on the boards)
but how do i do the input vs the output side of the equation?
Is it

solar - 12v connects to a general bus that connects to the charge controller connected to the dc dc converter?
something like this?

 

[sunshine_eggo]

DC-DC are generally only one way, i.e., they convert one voltage to another in one direction.

Your sketch will send panel voltage (17-22V typical) to the motors, possibly pop the DC-DC and never charge the capacitors.

 

[bruce_loco]

So like this you mean?

 

[sunshine_eggo]

Closer. What you may be missing is that a 12V solar panel outputs 17-22V typically, so you're going to need to step the panel(s) down to 16V. Can the supercaps handle > 16V?

 

[bruce_loco]

Closer. What you may be missing is that a 12V solar panel outputs 17-22V typically, so you're going to need to step the panel(s) down to 16V. Can the supercaps handle > 16V?

You Are right, the panels are rated at 18v, they already come with a stepdown voltage controller 24-12v to charge 12v batteries, which I assume is just a boost buck converter with an LCD.

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This is the controller:

https://www.amazon.co.uk/ECO-WORTHY-Controller-Intelligent-Regulator-Battery/dp/B08MTLQZ9M/ref=sr_1_9?crid=G2GLFMX8MI3M&keywords=eco%2Bworthy%2Bsolar%2Bpanel%2Bcontroller&qid=1684571662&sprefix=eco%2Bworthy%2Bsolor%2Bpanel%2Bcontroller%2Caps%2C66&sr=8-9&th=1

However a better encased set of buck boost converters moded with bigger caps(or more caps in parallel+filtering cap) replace the pots with resistors as this will be fixed output, no need to fudge about with a POT plus less chances of failure due to environmental factors

Sure I could ignore all of this and get 5 supercaps at 2.7 with the vreg boards and get 13.5v, no need to fudge about

However if I get the 6 bank and 2 vreg, so I get 16.2v, even with inefficiencies I can still have longer 12v output due to the step down and discharge curves(i think, but I could be wrong)