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I did the math on my UPS and posted in a previous UPS thread: 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 battery with that same...

The fancier NiMH chargers have a discharge / recondition function. like this one for example: https://www.amazon.com/Panasonic-BQ-CC65AKBBA-Advanced-4-Position-Indicator/dp/B0B2WXJH43 Even if it doesn't discharge as deeply as you are trying for, it would presumably have the advantage of...

What if 1 hot cell started melting the plastic wrapper, shorting 2 cells case-to-case? A chain reaction could commence shorting one to the next as the heat grew.

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!

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

You're not trying hard enough.

Toyota's been putting 100% Aluminum micro channel evaps and condensers in their cars for about 20 years now. They stick those things in the front of the car and let 'em collect dirt, rain, bugs, gravel at 70mph for 10 years and they still work. Not sure why they can't catch on in stationary...

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. 🤷‍♂️

I haven't bought any panels yet. Still have some other honey-do items to complete. For now I watch for bargains to see if something is so good that I have to buy it and stash it in the shed.

I just watched a handful of these units sell from a solar company liquidation auction for about the same price or a little more. Seems like a good deal.

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.

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)

Ok the fixed link is way cooler!

It plays Dire Straits? Pretty fancy!

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?

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

Hmm, I thought Renvu went out of business because their website didn't come up at all with my adblocker turned on. I fixed that and I see they only have 1 panel for sale in <10 quantity and the size is too big and the price is not great, aaand they don't even mention which location has the item.

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.

Any straight-thru wired LAN cable should work just fine. And to be fair to Victron, they don't claim otherwise and they don't play the "ooh our cable is better and should cost $100" game.

I can drive to Sacramento and pick up Znshine 405W panels on clearance from A1solar for $104. That's the best deal I've found so far.

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...

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.

Big Clive is a worthwhile watch for all kinds of teardowns.

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/

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...

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...

Is that 6 awg regular-old THWN stranded, or the fine-stranded flexible stuff? or either?

2 days. Fridge, TV, WiFi, gas furnace blower (if winter).

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?"

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.

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?

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.

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...

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...