Re: Opposed piston Diesel engines / was interesting engines

On Friday, September 10, 1999 at 3:00:00 AM UTC-4, DANKIRLIN wrote:


We had two of their next to the very smallest 10 cylinder engines aboard my frigate that drove our 500KW auxiliary generators. They were louder than all get out.
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On Thu, 1 Feb 2018 06:40:17 -0800 (PST), snipped-for-privacy@gmail.com wrote:

Be prepared to see Achates opposed piston multi-fuel engines in light trucks within 5 years. they are 2 stroke turbo-compounded engines with INSANE torque that fit into the same space as a common inline engine like a cummins, or V8 like a Powerstroke.
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wrote:

Like the Kei cars in Japan? I've been seeing 440cc and 660cc engines listed in Toyota Car and Truck shows lately.
I wonder if they could support generators for massive electric car range extension. That might be the clincher for selling electric cars to the masses, even though 90%+ of people don't need that kind of range.
Rather than rebuilding my 4.7L Toyota engine next decade, should it need it, I'd rather put the money into an electric motor and batteries.
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
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On Thursday, February 1, 2018 at 12:27:33 PM UTC-5, Larry Jaques wrote:

I've thought the same about my '99 Mazda as well, but maybe it's a little old...
As Al Gore said, "Electric cars aren't for everyone. They're just for about 90% of everyone." As range improves, I expect that number to reach well above 90%.
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We don't have anywhere near the electric generating capacity to support that. ... I finally found a fairly decent and inexpensive battery monitor for home energy projects: (Amazon.com product link shortened)
It draws a little under 1 Watt for its own use, the current falling as the voltage rises. With the display constantly lit it uses 35mA from my 24V batteries.
The voltage error wandered as much as +/-50mV, 5 counts, as I stepped up the input from 7.5V to 31V while measuring it with a 5-1/2 digit Fluke. The current tracked my meters within +/-0.2A to 15A. It has a 200A 75mV shunt so an error of 0.1% of that isn't bad.
The downloadable manual is much better than the usual barely comprehensible garble. Apparently long-pressing OK at CLR rezeroes the current measurement. Otherwise the meter did what the manual said it would.
Discharge current is positive, charge is negative, to make the graphic gauge rise as the battery charges. Starting from reset on a full battery, the Amp-Hour total increased as the battery discharged and decreased as it recharged, passing through zero to negative when the battery's charge current acceptance at 13.6V had fallen very low, which is a good indication of a nearly full charge since the battery doesn't waste charge as hydrogen if the charger limits the voltage there. Exit lights and computer UPSs recharge lead batteries safely but slowly indoors that way. OTOH the Watt-Hours total just increases and after the initial discharge where it's useful it double-counts energy in and back out.
While dedicated Lithium battery fuel gauges can self-calibrate this one has to be told the battery's Amp-hour capacity. The capacity indication appears to ignore the excess A-h charge when a lead-acid is on float and starts the discharge percentage at your programmed value of 100%. It looks like the A-h total will drift due to full charge float current unless reset. I'm hoping the A-h total will remain useful while the battery is partly discharged during an outage..
I tested it with full discharge cycles on an old 12V 18A-h AGM that has deteriorated to 2.5 Amp-hours, and shallow cycles on my 100A-h solar bank. The next week's weather forecast is too overcast for a good test of solar recharging.
I didn't try the wireless connection because the USB one was reliable, unlike the 30A + relay version of this device.
Previously I used separate unidirectional meters to measure Watt-hours in and out. The problem is that a lead-acid discharges at a lower voltage than it charges, which creates a difference between the Wattage totals. Voltage would be a good indicator of state of charge if I could leave the battery alone to settle for a few hours, but not when I need to be using the power.
-jsw
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On Thu, 1 Feb 2018 19:37:14 -0500, "Jim Wilkins"

Oh, I know that. We need to go modular with nuclear bases to support the solar and wind intermittents. Lots of work has been done recently to heat fluids with solar during the day for conversion at night to electricity, but that will have to be done with excess solar.

Yeah, not bad. Digital DC Multimeter 0-90V 0-100A Voltmeter Ammeter Power Capacity Time Meter | eBay https://is.gd/2uS2sC with shunt board looks similar, with similar pricing. ($38 for the 2 pcs, lower cap, higher price) The shunt is a separate piece on the DROK? It appears that many Chinese vendors have embraced Amazon and the price differences are minimal between Ebay an Amazon nowadays.
I picked up 5A, 20A, 50A, and 100A shunts for five a pop off Ebay so I can avoid the errors, thinking they were worse. The Bayites we discussed have since dropped in price a bit. It's about time for me to start cutting holes in aluminum panels for their mounting.
Now that I've taken a year off to decompress, It's time ta git me little solar farm up and running. It was nice not =having= to go out into the cold mornings. Blackberries have taken over the East 40 again, though. Grrr...

Cool. Do you miss the Chinglish, though? :-/

Yes, charge current is a good indicator of SOC. UPS batteries seem to last longer with their stingy system chargers, a good thing.

Hmm, not as useful.

These sounded smarter, at first, than their Bayite predecessors.

A test bed is a test bed, but <1/6 cap? <snort>

We're finally having dry and, if you can call mid-50s spring-like, welcomed weather here. Bright sun and blue-skied afternoons, YES!

USB seems like a handy connector style. Standard USB? I found some micro boards/connectors on Ebay a while back @ dirt cheap $, and I have lots of std/micro cables around for my cell, Fire, and Kindle. What was wrong with the relay version, circuitry or relay contact failure?

Yeah, that sounds self-defeating, with the lead/lag A/V play, but now you know.

True. What are you going to do with all that -power-, though? 2.5Ah! Wow. <gd&r> That's enough to idle your laptop with the monitor off.
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wrote:

I've heard that power wheelchair batteries may not last very long because the user charges them only while in bed, so they rarely reach full charge. The numbers are 1-2 years, compared to maybe 5 years for the same battery in a golf cart that has longer to recharge. I know from a job repairing medical equipment that the owners buy the cheapest wet batteries when the original AGMs die. Supposedly that's a consequence of the slow and fussy bureaucracy of government healthcare.
My backup system could have the same charging problem. I hope a week or so at partial discharge followed by a full equalizing charge outdoors after the grid returns won't hurt the batteries much.

More importantly the VAC-1100A measures bidirectional current in the ground lead of the supply that powers it, meaning that one current sense input functions at as much as -37.5mV below the negative power supply rail. The other +/- current meters that I have need an isolated power supply that lets them float the negative-lead shunt up to their +1.2V reference voltage. However the meter vendors don't offer a suitable step-down switching power supply with an isolated output. I've been using cheap surplus cell phone chargers with obsolete plugs, which are fine for bench testing but not for running on DC during power outages.
I've mentioned both this power supply problem and the poor/absent manuals to Drok. Perhaps they listened.

It was the best one remaining from a bunch of second-hand exit light AGMs I acquired around 2010. Its low capacity minimizes cycle times while I check out the discharge testing hardware.

A flaky USB connection, and possibly intermittent measurement errors, I only checked it briefly and may have misread the tiny display. It's for unattended discharge capacity testing using the relay to disconnect the battery at 10.5V, but those tests are time consuming and way down on my to-do list.

I thought I could correct the Watt-hour difference with a simple factor like 12/13, but the discharge voltage drop also varies with the load current, SOC and battery age. For example after that old AGM drops out at 10.5V @ 5A it recovers to about 12.1V. I pulled 5 A-h out of it at lower current.

I have nominally 4 KWH of storage and a measured 300 Watts of 24V charging power, slightly more than enough to keep up with the fridge, two computers and the TV or to replace what the fridge used overnight. .
-jsw
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On Fri, 2 Feb 2018 20:11:26 -0500, "Jim Wilkins"

Huh? Not fully charged after 8-10hrs?

My neighbor found out that Medicare won't allow things to be recycled. They will fund new items only. 2-month old hospital beds, 6 month old 3-wheeled electric scooters, etc. which are perfectly serviceable are just tossed. That sickens me. Penny wise, pound foolish, as the saying goes.

It shouldn't, but with _your_ batteries... LOL

That's good.

OK, it does what you need.

It's hard to stay attentive to long-term monitoring. I tend to set my watch for a handful of minutes, then go check, resetting the watch alarm each time.

Internal resistances play havoc with everything, triggering dropouts, alarms, etc. Batteries can be perfectly good for most things, but try to start a car with one and it will go TU in a heartbeat.
What do you make of these: 12 Volts Lead Acid Battery Desulfator Assembled Kit | eBay https://is.gd/5cBjNg <$8 (120Hz pulse)

Whew! I'm glad it's not just that one battery. :-) What does that 4kwh work out to in ah? 166.7? Not a bad set. (Pair of group 27s?)
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wrote:

The firms I worked for restored used medical equipment to a condition Medicare would accept, as long as the customers' paperwork was fully in order. And that was a major issue for many of the elderly. I know some fell through the cracks but not why. Just doing my job here, Ma'am.
As I've seen in my own affairs the system has little or no flexibility to accomodate unforeseen exceptions, yet it's easily milked by those who understand it. The government strives for fairness, economy and value are completely foreign to Uncle Sugar. At least the industry pay scale was nice. -jsw
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On Sun, 4 Feb 2018 13:36:13 -0500, "Jim Wilkins"

I think that has changed now, according to those two instances I saw. Refurbs were just fine with our folks, who grew up with the Crash. I think most folks today, other than Millennials, would accept them, too.

But of course.
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wrote:

The government paid big bucks for me to replace the seat, arm rests and wheel bearings on a wheelchair at a factory-authorized dealership. I don't know where the guy who sold refurbs out of an old barn for -much- less got his parts, maybe China?
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On Tue, 6 Feb 2018 09:38:04 -0500, "Jim Wilkins"

In the 21st century, or before?
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wrote:

https://www.yellowpages.com/concord-nh/used-medical-equipment-supplies
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On Tue, 6 Feb 2018 20:27:01 -0500, "Jim Wilkins"

According to my neighbor, Medicare won't pay to rent or buy used items for Medicare patients. The local rental place confirmed that when we picked up the walker and wheelchair for her dad 4 years ago. He could buy anything he wanted, but the gummint would only cover new items. I'm wondering if this is a new thing.
So, the questions were 1) When were you were paid by the gov't to refurb stuff? and 2) To whom was rented/sold? (not including the F/A dealer)
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wrote:

1) I was never paid directly by the government, though I fixed VA hospital equipment. The time frame was around 2005. 2) Individuals and facilities who needed it. I knew nothing about billing beyond the time spent and parts replaced.
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On Fri, 9 Feb 2018 07:51:14 -0500, "Jim Wilkins"

OK, thanks. I wonder if the VA was/is different in usage allowances.
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