jstsch · HackerTrans

vor 4 Tagendiscuss

Two Toyotas. The steering you apply, even with almost no torque, always overrides lane keeping. Super dangerous. No beeps when that happens. Whereas with my Tesla you’d have to force it out of autopilot. Or fight a bit back if the car corrects you for safety.

jstsch

vor 4 Tagendiscuss

The regulations are great, in theory. In practice, I've noticed that implementation of the technologies are lacking. So on paper, lane keeping will keep you on the road when distracted. In practice, it does not. You'll be beeped at a million times, though.

jstsch

vor 3 Monatendiscuss

I dislike ‘energy religion’. Nuclear is necessary for Europe. We simply can’t heat our homes and power our industry with renewables in winter. At the same time wind and pv can be built up faster and is simply cheap. Hydro where topography and local bio conditions allow it. We need all those technologies, so we can move away from fossil (climate, resilience and depletion).

jstsch

vor 3 Monatendiscuss

Set it up myself, mostly. Some specific tasks like bringing three-phase power to the garage and hooking up the breaker box I did with an electrician. But installing an additional circuit inside the breaker box, or putting new conduit up, is easy to do safely yourself. Pre-wired breaker boxes can be configured online and are cheap.

The battery is 16kWh. Effectively around 14kWh, since you never fully discharge. LiFePo4, so no chance of spontaneous combustion like other battery chemistries.

I'd say the months Nov→Feb are tricky, although since I have quite a bit of excess solar capacity there are even in December plenty of days where the battery pulls me through the night.

Charging/discharging from/to the grid is possible, since I have a retrofit inverter (AC to battery), but not doing it yet, have to do a bit more research (dynamic pricing, tax is >50% of the kWh price in NL, etc).

jstsch

vor 3 Monatendiscuss

Every installed PV-panel is a dozen barrels of oil (eq.) less CO2 in the atmosphere. Plus, so much fun to generate your own power! Can highly recommend it, even starting small.

It's addictive though. Living in the center of the city (The Hague, NL), with a home battery, I'm now 100% self-sufficient electrically for 10 months of the year.

jstsch

vor 3 Monatendiscuss

Same! Set up a DIY home battery system and needed something to communicate with the inverter and battery over RS232, RS485 and bluetooth. Had an old Raspberry Pi-B with 512MB RAM lying around.

Running 3 python scripts as daemons would become a tad heavy and was a bit worried about serial timing. So used Codex to rewrite them in Go. Cross-compiled them, deployed the binaries and they're now running very comfortably on the pi. A few MB of ram per daemon. Making good use of an almost 15 year old device.

jstsch

vor 6 Monatendiscuss

> especially not to spec torque on terminal connections and botched crimps leading to hot spots

This was indeed my greatest concern. However the battery came with pre-crimped very solid DC wires, and nice push connectors for the battery itself. The battery also has an integrated DC breaker (great!).

The system runs 3KW max, so I just added an additional breaker (with RCD integrated) in the conduit box. In NL this is something a DIY-home owner easily can do themselves :) (just use the right solid/flex stranded cabling for the connectors, etc...)

jstsch

vor 6 Monatendiscuss

I will do a write-up in a couple of days. It's all relatively simple, you just have to expect terrible documentation and do a bit of reverse engineering and serial sniffing. I expected the battery to be complicated, but it turned out that the inverter was.

You'll encounter stuff like: manual says use RS485 port on Battery for GroWatt inverter → need to use CAN port on Battery. Meter Port (RS485 [serial] over RJ45) wiring on GroWatt is unknown (A: white orange / B: white blue, cross them over). Dinky RS485 serial → USB converter needs a 120ohm resistor between pins for line termination. Growatt meter port expects a SDM630 meter, not a DTSU666 (hardcoded), so vibe code another emulator. DIP switches for RS232 connection need to be both on the ON position (undocumented). CH340 USB→serial converter for RS232 does not work, but one with a Prolific chip does. Etc. etc. etc :)

Oh, and the biggest one... I was expecting to be able to just send a command, 'charge at 500watts', now... 'discharge at 2000watts'. But no. You have to emulate a power meter and the inverter will try to bring the net power to 0. Fun! :)

jstsch

vor 6 Monatendiscuss

Battery prices are getting really low, if you're willing to do some DIY. Just received a 15kWh battery from China. A 'Humsienk'. Combined it with a GroWatt SPA3000TL-BL inverter.

Total price, 1600 euros. So close to the magical 100 euros per kWh. Driving it with some interesting combinations of Raspberry PI's and serial interfaces and custom written Go code, but it works... :)

jstsch

vor 7 Monatendiscuss

Yes. Just take a look at this picture of the accident. You can instantly see where the proportions go wrong. Not survivable, even at low speeds.

https://cldnr.prod.webx.talpa.digital/talpa-network/image/fe...

jstsch

vor 7 Jahrendiscuss

Wow! What an achievement. Putting it all together, including the YM3438 FM chip, great work!

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