Releasing the Magic Smoke

[sternwake]

Hey! There was only one incident with a potentially dangerous
overcharged 24 volt nicad hedgeclipper battery

[sternwake]

Yesterday's smoke involved the newly arrived 1800 watt voltage booster.

I wired it up to my 18Ah AGM battery, put my cheapo centech  multimeter leads on the output on the 200 scale and see 20.20 volts on the output.
I then disconnected it from power and then put my trusty several year old wattmeter on the output, hooked up the battery to the input.  Saw 20.21 volts, and busted out the jeweler's screwdriver to move the voltage pot and see output voltage respond.  The only load in the output was the wattmeter itself, i had hooked no load to the wattmeter yet.

These are something like 20 turn potentiometers, meaning 20 full turns to go through the full resistance range. no way a quarter turn would increase voltage more than a volt or 2.

I spun the pot clockwise, something made a click sizzle, and the wattmeter went dark.

When the cursing subsided I put the cheapo cen tech multimeter back on the output leads on the 20 volt scale.  It read 1, meaning voltage was over 20. I moved dial to 200 volts scale and it read 90 volts!!!!!.

No wonder the 60 volt maximum wattmeter fried.

On close inspection of the main transitor legs, I saw the worst soldering I've ever seen on any product ever.

There is fractured solder joints, what appears to be missing transistor legs as well as solder 'joints'  completely lacking solder!
   
   
   

Now, i should really have inspected this before getting overexcited and hooking it up to a battery, and then hooking my wattmeter to it.

NOt quite sure how they solder these components, a friend says they insert all the components and then send it on a conveyor over a molten solder pool to join all the components, rather than an individual sitting there with a soldering iron atttaching things one at a time.  Supposedly they do many at a time.  If so, they obviously got the solder level wrong, and the person inserting the transistor legs into the circuit board did not snort enough meth that morning, or perhaps too much.

It is likely the whole run of these devices is as poorly soldered as this one.

Live and learn.  I'll be closely inspecting each electronic  gizmo from here on out before connecting anything of importance to it.

I got to log into ebay and demand a refund.

I highly doubt seller will pay to return and inspect it.  it is likely I might try to solder all these transistors and test it for function.  Should likely get a few more free or cheapo harbor freight multimeters if/when that time comes.

What is 'amusing'  is that they went through the effort to grinding off the identifying markings on this particular processor chip. as if it is a huge secret they can;t allow others to see.
  Now if they did this before or after soldering is unknown, but it after, then the time it would take to do this the tech would easily see the ridiculous solder joints on the main transistors.

   

[sternwake]

The newest watt meter which arrived last week,  the voltage read low, as well as the amperage. 
Both readings would, after a while, start jumping around enough that its readings could not be trusted.

Sometimes it was fine and other times it would jump around.
Today, wattmeterless, i tested it again  it seemed to be steady, and devoid of I wanted at least one semi operable one.

These wattmeters have a shunt. A shunt is a resistor of a certain impedence. measure voltage drop on each side of this shunt then the amperage flowing through it can be calculated.

Since mine was reading too low, it struck me that I could grind some material from the shunt to increase its resistance and get it closer to accurate.

I got it dialed in perfectly with my DC clampmeter via slow removal of copper then testing, at 2 amps of load, but the voltage was still 0.06 too low.  I was  not  super happy but at least I would have one wattmeter functioning.

So I Install it back in its plastic casing, plug it in, and with no load on it, it reads 0.2 amps.
i take it apart, it reads 0.00 amps.  I squeeze the circuit boards together and it reads 0.5 amps. i squeeze harder and amperage reading increases.  WTF!!!!

Out comes magnifying glass.  this serves as the hinge type of joint on the two circuit boards:


Look at these solder joints. Some are clearly lacking solder.  It seems like this is definitely the culprit not only for the squeeze amperage, but also the instability at times. 

   

So I reflow and add some solder, easy peazy, it should then work fine and perhaps the voltage reading will read more accurate and the instability should be gone...right?!??!!!?

Well there was a slight improvement, but squeezing the circuit board together would still cause it to read amperage when there was nothing flowing across the shunt, but with no pressure it read fine and was dead accurate measuring  2 amps of load.

So I figure i am going to modify its enclosure so thet when it is screwed together, it does not squeeze the circuit boards together and should at least be accurate enough  on amperage to be useful

While doing this I leave it attached to power, and after a few minutes the numbers and letters on the display disappear, there is just a blue screen.

How bout that, all that wasted effort, wasted money.

Where's my Fvcking sledgehammer?!!!!!!!!!!!!

Arrrrggghhhhhhhhhhhhh!

The fried wattmeter trio:

   

[Roadtripp]

Dang, better luck next time. Got to wonder if some of the inexpensive “buckers”, meters, etc are tested much or at all before packaging. I’m afraid to hook power to the ones I got lol. Even if it doesn’t cost much I too dislike seeing anything go POP, crack snapple fizz, or emit smoke. But I need to setup a little electrical work station to test stuff.

[sternwake]

for a lot of my tests, i was using a blue seas 12v ciggy plug, as while ciggy plugs suck, they are convenient in that one can pull them out just enough to break the circuit and push them in to make it.

I had forgotten that I had blown the fuse in this one, and instead of using a new glass fuse, which I likely had no extras of at the time, I used aluminum foil around the glass fuse.

well this ciggy plug is no more, the internals melted and a bunch of solder leaked out from around the fuse itself.

I've ordered 3 more wattmeters. One of them is a '200' amp version for 20$. it has a slightly different plastic casing and display than the others. and comes with 8awg leads instead of the usual 12awg

https://www.ebay.com/itm/200-Amp-Watt-Me...2078!US!-1

One of the reviews says it locks up, same as the first wattmeter I smoked, which also came with 8awg leads, and which was also bipolar. I think these devices are a total crapshoot as to whether one gets a good accurate one or not.


i have also ordered the rectangular metal cased one rated for only 100 amps surge. I never bothered with these 'lesser' models, but the metal casing with screws on the side could be a bonus if less pleasing to look at. These 100 amp versions do not have ANY ventilation holes/slots, and makes me wonder if that is why they do not have the higher 130 or 150 amp ratings of the other marketed wattmeters in the plastic casing which do have ventilation slots.


https://www.ebay.com/itm/Digital-Monitor-LCD-Watt-Meter-60V-100A-DC-Ammeter-RC-Battery-Power-Amp-Analyzer/222929217724?epid=774981038&hash=item33e79de8bc:g:jCcAAOSwQ~ha1rTT

I also ordered the same style wattmeter I just ordered and which failed being a total P.O.S and waste of time and solder and emotion.

https://www.ebay.com/itm/150-AMP-WATT-METER-WITH-SPECIAL-HEAVY-GA-WIRE-WIND-GENERATOR-SOLAR-DC-INLINE/223608449165?_trkparms=aid%3D333200%26algo%3DCOMP.MBE%26ao%3D1%26asc%3D20171012094517%26meid%3Dcce64ffbe9374acf8c6e2996115ce997%26pid%3D100008%26rk%3D6%26rkt%3D12%26sd%3D392069619989%26itm%3D223608449165%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100008.m2219

All my previous orders were through amazon but without prime, one needs to order 25+ dollars of 'eligible' items in order to get free shipping, and the prices are usually more than Ebay too. I ordered these from US based sellers in order to get them quickly, but could have spent less if I were more patient and got them from China.

Apparently some of the '100 amp' metal cased ones do not have a backlight. Not sure if that is a huge detraction or not, but one can find them for as little as 6.50$ or so with free shipping.

I have a box full of 5 and 3 amp buckers that also has a few buck boosters, and a whols shitload of variosu resistance potentiometers. I will be taking more precautions to prevent shorts when testing things.

I included the pictures of the horribly manufactured 1800 watt booster in my complaint to the seller of the product, and demanded a full refund. No response yet, but if I have to I will file a complaint with E bay and should be reimbursed.

From now on all testing will be with 3 or 5 amp fuses or less on input and output of buckers/boosters and the loads will be things I do not much care about if they are to fail.

While the 1800 wat booster was a piece of shit, it was my fault for not looking it over with a magnifying glass first to see if the transistor and other electrical gizmos were properly soldered.

Hopefully the newly ordered wattmeters are not quickly destined for the landfill too.

[rvpopeye]

Your ongoing testing reminds me of me at one time.
I suspect the testing is worth more to you than finding the duds.
I'm enjoying your posts almost as much as if I flippin' the switches !

It seems your decision to check the soldering on the things is a must do if trying out the offshore toys.
May the smoke stay inside and the quest continue............

Tron on.

[sternwake]

The duds certainly bum me out.

I am rather amazed the prices of these voltage/current manipulation devices are as low as they are.
Some more smoke was released on a buck/boost unit after I removed alligator clips to insert the wires into the screw clamp jobbers instead. I think torquing the screws was enough to cause a short somehow. I certainly made sure no loose strands were touching each other.

That US based seller, jacobsparts, issued me a $5.95 refund in under 12 hours.

The 1800 watt booster device seller is chingrishing me through google translate, offered a new replacement unit which i denied, and then says they want the failed unit back, will pay shipping( I think) and then issue refund.

So to add to the tests, I need to make sure that when using the screw clamps on stranded wire to test for continuity between + and - before hooking it up to a battery. I hate these compress stranded wire under screw type of terminals anyway, but they are convenient.

Had I just soldered the wires to the adjacent pads I believe the Jacobsparts buck/boost unit would still be operating, but perhaps not, Ill never really know for sure.

I have 3 more B/B units on their way from china, one the same as that with just failed, but 1$ cheaper

New '200 amp' wattmeter just arrived, I freaking hope its accurate with stable readings.

[sternwake]

Damn each and every aspect of everything, from the beginning of time to the very end!

The 200 amp wattmeter reads voltage accurately, it reads amperage accurately enough for my purposes
minimum voltage
Peak watts
peak amps, are all accurate.

but plug in a load for a certain amount of time, and the KWH and AH readings are way out of whack, it is as if they  calculated that there are only  45 or 50 minutes in an hour instead of 60.  Is there such a thing as metric time, Chinesium time?  WTF!

I have a new seat heater heating pad whose wattage/ amperage reads rock steady at a steady  voltage. I powered it through my meanwell and the two wattmeters, the one that's been connected to my meanwell power supply since october 2014 and this new wattemter inline. They should read the same, or at least very close to each other.

and instant amps volts and watts were very similar,  but amp hours and watt hours read 20-30% higher on old wattmeter as opposed to the new one.

So I went to test them hold that load for a certain amount of time, do some simple math, to see which one could be trusted, and both of them are so out of whack with reality I want my sledge hammer, and I want to swing and miss it for the first 15 swings before connecting.

And to top off my rage, another wattmeter arrived.  same appearance and box as the one I most recently ordered from Amazon, but this one was cheaper, and from E bay. I hook it up with no load and it reads 0.14 volts low, worse than the amazon one!
Then I squeeze its casing when it had no load running through it and it read 0.5 amps! More amperage displayed the harder I squeezed it.  open it up to fins the exact same circuit boards and soldering  of pins between them just as poorly done, and rectifying that had no effect on anything other than wasting solder and electricity heating it.

Completely enraged, it found its way onto the concrete floor and a 4 lb lead fishing weight got hurled at it, and surprisingly, it did not miss.  however it was not nearly as satisfying as it should have been.

Nice waste of 11$  That's like a 12 pack of rolling rock I could be swilling right now.

Now it seems that  pretty much every amp hour figure, or watt hour figure, I ever recorded with these wattmeters is inaccurate, reading too high by 15 to 30%, depending on which freaking wattemeter I used.  I noticed discrepencies before with the one windynation wattmeter and ignored its kwh and ah figures, but never thought to actually do some simple math with a steady load applied for a specific amount of time on the other meters I assumed were generally accurate enough.  I mean its simple time, 1 amp applied for exactly 1 hour is 1 amp/hour, not 1.38 fucking amp hours....... you goddamn motherfucking product designers/programmers!

Arrrrrggggghhhhhhh!!!!!!!!!!!!

Ignorance was/is such bliss.

Apologies to anybody who purchased these wattmeters on my recommendation.

Now i need to find something I can trust that  is as convenient to hook inline on individual loads or charging sources when i want to measure how much they consume over a period of time.  I have seen no other product which records surge amps or watts though.

Instant amps and volts and watts are fine, as are peak/surge amps and watts, but add the element of time for amp hours or watt hours and these effing things are wrong wrong wrong.  If I have to use two devices hooked in line to get all the figures that one of these wattmeters should be able to do on its own, I am going to lose it.

The only shiny note is my fridge consumption figures are actually lower than I reported, and they were pretty low to start with.

[sternwake]

The 200 amp new WattMeter displays the total time the load has been connected.

I have connected it to constant non cycling steady load, at the same time i started the stopwatch timer on my phone.

Phone 1:41:28
WM 1:35:22

So it is 6+ minutes slow, in an hour and 41 minutes, at 14.6v under a 2.67 amp load.

I suspect the clock's accuracy will change with different voltage too.

Futhermuckers couldn't get a simple clock right.

Of course KWH and AH readings are way off when an hour cant be properly measured.

[sternwake]

Hmmm. my own logic circuits misfiring, I guess dental pain can do that. At least that's what I'll blame, and not surfing for weeks due to crowds and that crowd's mentality. Come on Tuesday, freaking hate summer.

Just timed a steady unchanging uncycling 2.42 amp load for precisely an hour at 13.25v, by my phone's stopwatch.
At the end of an hour I pulled the load, and the HTRC wattmeters timer stops and amperage and wattage drop to zero:

The new HTRC 200 amp wattmeter displayed 2.42AH, and 0.03KWH but its clock/timer only counted 00:56:31
The Old gtpower 130 amp wattmeter displayed 2.747AH, and 36.4WH. This wattmeter has no clock/timer display

I restarted the test for 00:03:29 and:
the 200 displayed 2.46AH but 0.01KWH .... how did it drop 0.02KWH???!!!! perhaps once load resumes it resets to zero and anything after registers 0.01kwh

The 130 displayed 2.909AH and 38.5wh

2.42 x 13.25 =32.065 watt hours The GTpower130 read 4.33 Wh too high and 0.32Ah too high

0.03 KWH = 30WH so the htrc read Ok on the watt hours before i stopped the load, it just does not have watt hour resolution

The GTpower is measuring the current of the HTRC, but they read within 0.01 amps of each other. My DMM does not measure current and my DMM doesnot register any current this low of the wattmeter itself. sometimes it will jump to 0.01a but I can squeeze out a fart and get it to read 0.01a too.

It appears i can trust the Ah figure of the new HTRC meter at least in the 2.42 amp range, but not its own clock and not the KWH figure as it inexplicably dropped when I continued the test for 00:03:29 more. according to my stopwatch, yet the timer on teh htrc reads 00:59:52.

The GTpower wattmeter I have been trusting to be generally accurate on Ah figures is reading 0.31Ah too high each hour, at least under a 2.42 amp load .

Too bad I did not perform timed tests on the smoked wattmeter(s)

The least expensive 100 amp metal enclosed wattmeter is supposed to arrive tomorrow. Perhaps I should not try to get any 8awg to its circuit board and leave the 12awg in place.

At least the fridge consumption 24 hour test with the HTRC wattmeter on Amp hours, will be precise enough as the fridge averages a 2.42 amp load when the compressor is running. The clock on the HTRC cannot be trusted, but I can figure out how many minutes on average it ran by adding 00:03:29 to each hour it accumulates as the timer only climbs when it registers a load, and i do not believe it will register the 0.03 amp load ( rated) of the internal fan or the parasitic load of the compressor controller.

Its a shame that the watthour or KWH figure is not really to be trusted as that accounts for changing battery voltage whereas amp hours do not, unless the amps increase as voltage decreases, which it might, depends ont eh load, cant really remember on my fridge and the amp figure drops the whole ~5 minute compressor 'on' cycle.