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opensolarproject / OSPController

ESP32 Smart Solar Charger - the Open Solar Project

https://github.com/opensolarproject/OSPController/wiki

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Drock question #21

Open MikeGarber opened 3 years ago

MikeGarber commented 3 years ago

How does your PSupply survive, given https://www.droking.com/cs/support/topic/backdriving-the-200310-as-a-solar-battery-charger/.

Mine didnt.

t413 commented 3 years ago

Holy crap, it killed yours? I’m so sorry! I’ve had numerous numerous of these drok’s and that’s never been an issue. What exactly happened?

I do support running with a diode though. In that case it can’t read the battery voltage when it’s not charging which means you’d want another way of monitoring it. Support for energy monitoring is a big todo item for me

MikeGarber commented 3 years ago

Been there, did that (if you read the DROCK thread). I suspect it has to do with the leakage thru the Schottky diode I used (also asked in the thread but unanswered)

With a regular 5A power diode, there's no apparent current monitoring... https://www.droking.com/cs/support/topic/charging-battery-with-the-200310-current-monitoring/

t413 commented 3 years ago

Well it's very strange that your Drok died from being battery-side powered. I've had a drok running 24/7 for 1.5 years now being back powered at night and at least one other user around the world doing the same.

If you'd like to try a different power supply option beyond Drok– I've now written and throughly tested support for DPS5005 buck converters (only the ones that come with either USB or BT though, importantly).

MikeGarber commented 3 years ago

Who knows? They mightve changed something.

As to DPS5005.... modbus, eh?

I already ordered some hall effect current sensors & if I can continue to count on this PS for CV mode, I can FORCE it (essentially) into CI operation.

But that DPS5005 looks WELL to look into!! Thanx!

rin67630 commented 3 years ago

Backfeed kills the buck MOS-FET if there is enough current flowing backwards. The built in Schottky diode in the MOS-FETs aren't rated for much current, far less than the forward current. A small inadvertent short on the panel side and you are greeting the magic smoke. You should operate your DROK with an ideal diode module:

between the DROK and the battery if you want to minimize the GROK own consumption overnight, but you lose the battery monitoring or
between the DROK and the panel if you want to keep the battery voltage monitoring, but you lose ~ 1 Ah overnight backfeeding the DROK.

rin67630 commented 3 years ago

I just checked a DPS5020 for it's quiescent currents at 14V

forward from the panel: 40mA. That could have been acceptable, but
backwards, reverse-fed from the battery: 115mA!
And it feeds back to the input: a panel connected could add even more current.

You really need an ideal diode module if you don't want to waste ~ 20Wh during a long winter night.

A DPS 5005 is less wasteful: it draws 40mA backfed. But that is still ~7Wh wasted when it's hard to get some juice from the scarce winter sun.