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I'll show up to buy the panels in a rusty Civic without a muffler. I'll be 20 dollars short of what we agreed upon because "I had to give my friend Spider gas money to get here." Can you help me get them in the back of the car?

It must have been a 240V split-phase inverter... they have 2 legs!

Here is the code and the basic idea for the Raspberry Pi Pico grid frequency counter: https://github.com/jbolhuis/pico-grid-freq My test implementation has been stuck in breadboard form for, oh geez, 1.5 years now, lol, still working.

This is great stuff. I'm just getting started with a battery big enough to get us through a power outage. When my wife complains about all the new parts, I just say, "Hey, this is better than my last hobby. Remember when I started homebrewing beer and it made me forget how to drive?"

Tons of people spend $10k extra to get the fancier version of the same basic car, just to have heated memory seats and a big huge sunroof. When the power goes out for an extended period, which it will eventually, you'll be smiling. Those other people will have warm butts as they drive to your...

So glad Dad would DIY most anything but also taught us to know when to call someone. "We're gonna build a wall and run water pipes ourselves?" "Heck yeah boy, I'll even show you how to sweat copper fittings." "Are we gonna move that big pipe too?" "Son, that's 4 inches of cast iron wrapped...

I built a grid frequency logger out of a Raspberry Pi Pico and a DS3232 precision clock module. Cheap, fun challenge. Happy to share details.

I see what you did there, lol. He probably meant MWh maybe?

and you could adjust the propeller so that the motor runs at the sweet spot nearest the maximum power point of the solar cell.

I built a logger for my Cyberpower 1500 UPS when I expanded the small lead-acid to bigger lead-acid a few years ago. The charging 'algorithm' is the simplest possible: charge to 27.2 volts (400mA max) forever. If you run it down to the low voltage cutoff (21.9V) it takes over a day to recharge...

I had a 9V AC wall wart lying around. I cobbled this together - it's a half-wave rectifier -> voltage divider -> 1300 Hz low pass filter (because why not) -> schmitt-trigger inverter. (don't care about the inverting part but the hysteresis is helpful to avoid spurious transitions. If you're...

The Victron MPPT calculator tool is super handy: https://www.victronenergy.com/mppt-calculator and it probably already has your panels in the chooser. You can choose different combos of series / parallel to see the differences.

Thanks Mike! It's a great idea and easily testable since 1) this circuit is still in a breadboard and 2) I have 19 more 74HC14 chips just in case. Yeah I wasn't too worried about the exact trigger time since I'm averaging over 120 cycles it works out ok. I'm happy with the output - when the...

You don't need to source a tiny Anderson connector for the precharge part, a much smaller DC connector stolen from any RC car/drone battery would do the trick too.

Put the dry ice inside a box so that the CO2 is forced out the bottom, air-hockey table style, voom you got a hovercraft!

Years ago as a young'un I built my own bicycle trainer for winter use. I had my tire ride in the groove of a regular car alternator. I found the perfect load to be one plain old sealed beam headlamp. So, about 50 or 60 watts of useful power from that setup. These days I ride a fancy exercise...

Wire is expensive, and 24V inverters are usually slightly more efficient. Those are the main reasons to recommend going up in voltage. That is fine advice when the inverter is the only DC load. Since you have other DC loads that are 12V, it makes little sense to choose anything but 12V...

In the 1970s, we used the AM radio in a Chevy pickup to find arc trouble in the electric fence. (also useful for detecting thunderstorms)

You're not trying hard enough.

Did you impulse buy that pallet of 31 panels in the 360-400 Watt range? Was it too many but you couldn't refuse? Do you live in the middle part of CA? I may be willing to drive over and give you green cash money (or paypal) for 6 of them. I'm aware of FB marketplace and other local...

Yep these things are all possible. In the case of my Cyberpower 1500, it's a pure sine wave model. I saw it had a temp sensor on the output transformer and a fan that ran when inverting. Then I tested the bigger battery while keeping a close eye on it. At a mere 10% load it didn't generate...

Ooh I saw this when Andy got these in his off-grid garage. P is power. So the 314Ah cell at 3.2V is 1005 Watts at 1C. .5P is 500W. Not sure why they changed this or how helpful it is. 🤷‍♂️

Lead acid batteries are the most recycled item in the US from what I've read - 99%. https://batterycouncil.org/lead-battery-recycling-success-story-on-america-recycles-day/ Busting open a battery on my own is just about the last thing I would like to do.

Zanydroid was right. Renvu was very helpful and made me a good deal on 6 for local pickup.

In my Seplos BMS specification, it calls out the temp sensor type: "Cell temperature sensor NTC value is 10K and B-value at 3435." This is a super common thermistor and you can find them for pennies per piece on Amazon - search "thermistor 10k ntc 3435" But first check the physical wire from...

So there are more things in email and phone than are dreamt of in my philosophy, eh?

I guess I was only thinking about my small house... Last time we spent a couple days in the dark I just hooked aux power to fridge, gas furnace, and TV. Very small bare minimum load.

The main issue I see is that UPSs often flog these little batteries like rented mules. My Cyberpower 1500VA UPS uses a pair of these small form factor batteries that are very commonly used. 1500VA at 24V is 62.5 Amps. For a 7Ah battery that's a 9C discharge rate. The cute little LiTime 6Ah...

It may be possible - according to this post Aims will share the protocol information. You may have some coding to do! https://secondlifestorage.com/index.php?threads/aims-lf-inverter-rj45-protocol-information.10348/

For the electro-curious, TVS diodes are there to do... almost nothing. They don't conduct electricity in either direction until the voltage goes above a certain point. They are meant to dissipate a quick voltage spike that might otherwise damage nearby components. The ones pictured here...