By way of introduction...
Hiya folks,
Electronics, you would think is a hard science but I see it as where physics and art meet. Deploy good designs principles then lots of fudging until it works good enough.
Simple systems are robust and increasing complexity increases opportunities for failure.
That's a sweeping statement but there is a tension in both directions. Trying to keep the design simple and solving problems with the lightest touch is where my head is at.
My journey started the same as many others, a desire for an alternative to the grid after a large storm took out the power for 2 weeks. You can't look at the world in the same way after that.
Who knows what the future may hold but from this vantage point things look not-so hot-so.
Why not build some resiliency and learn something?
A fairly typical story arc...
Started with 18650 li-ion and a HF inverter, then Ni-Cd and PowerJack, then a huge leap forward to LIFEPO4 and a Chinese EGS002. This was light years ahead of the PJ and the HF. More modest improvements were made with EGS002 mods, the Aerosharp toroid and sendust choke. This seems like most of the low hanging fruit, however the learning and system changes continue.
I've been enrolled in thebackshed university for some years now, haven't graduated and probably won't ever but I have learned and grown in confidence enough to overcome my huge lack of theory, knowledge and practical experience. I really am riding on the shoulders of giants.
Next stop, modularising with 100 x 100 pcbs then I'll dive into charge controllers.
Off grid since 2018 and I've been surprised how painless it's been.
Specs:
PV 8.5kW
CC 4 x 60A
LIFEPO4 16s, 1200Ah, ~76kWh (I no longer take notice of rainy days).
Ni-Cd 35s, 390Ah, ~16kWh
Inverter 2 x 4kW EGS002 (2 circuits), 1 x 5kW HF (backup)
Random pictures:
Quick and dirty in home indication of battery condition.
Original battery LIFEPO4 with Headway 10Ah cells 32p 16s
2nd battery LIFEPO4 with CALB 100Ah cells 3p 16s
3rd battery LIFEPO4 with EVE 280Ah cells 1p 16s
4th battery LIFEPO4 with EVE 300Ah cells 2p 16s
5th battery Ni-Cd with Saft 195Ah cells 2p 35s
Failed basket weaving however this one works great!
A visual indication when pre-charging the inverter's capacitors. No breaker splat!
LIFEPO4 battery overflow - dump system.
When the main LIFEPO4 battery is at maximum voltage then this system dumps the excess energy.
The top module switches on HWS elements (I'm learning oled implementation. I will redo this with the oled screen mounted directly on the board. This is showing 4 hot water elements are on. Signal is sent via RF).
The bottom module switches on the dump to the Ni-Cd battery and when that is full it dumps to heat bars.
Choke saturation tester. No longer flying blind :)
Cheers
da
