The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

[ratdude747]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

As in, convert a USB keyboard and mouse to PS/2??
If that's the goal, some old Dell and HP peripherals from the mid-2000's were made to be cross-compatible with both USB and PS/2 protocol. Just need a passive USB to PS/2 adapter to work. IIRC, the mouse that came with my family's Dell Dimesion 3000 is like this. I can look up the model # if you're interested.

The reverse (USB to PS/2 MS/KB) exists, of course. I have several cheap adapters that convert a single USB port to PS/2 KB and MS. The cheap adapters I work well, but with one caveat: cannot press & hold more than 2 keys on the KB (Ctrl+Alt+Del and similar still work, of course) and any key held down for more than 3-4 seconds gets released and you have to re-press it to activate again. The mouse portion works fine, though.

Microsoft made keyboards that had both, no adapter needed. I'm typing on one... it's a Microsoft Internet Keyboard pro. They also made an ergo version (I have a few of those sitting). I actually had a spare one of these but it was in rough shape.



I use mine because it's my favorite beige keyboard (used on my garage computer with the 24" trinitron) and because having PS/2 natively is good for the rare time I need to bench test something needing such. Also (like the ergo ones) it has a 2 port USB 1.1 hub in it, which I use with my mouse (freeing up the second USB on my KVM)

Link to the ebay listing I stole that pic from: https://www.ebay.com/itm/265378632477

I got all of mine at goodwill for well under $20 (and both were in good shape when purchased)... but that was years ago. . Just note that they only made them with both plugs on a splitter for part of the run. Older ones are PS/2 only, and one of my ergo ones (which happens to be a dell rebadge) is USB only.

[momaka]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

I still hate seeing you leave the US...especially for Europe with a potential world war festering there....but I'll stay upbeat here.

I doubt anything that serious would happen. Of course, with Putin being how he is, no one can be certain 100%.
...
And yeah, I'm also not super-thrilled about moving there either. But it's been set in motion already. No biggie, though - I can always come back here if I can't make it there. I just won't be coming back to the same area where I am now. I just can't afford it. Never could, actually. So this has been brewing for many years. But anyways, I'll cut it short here with that.

I was actually looking forward to it; along with critiquing.

Nothing to critique, though.
Well, reading through the posts, at some point I though I'd mention I'd be nice to put some labels on the switches and lights... but noticed later on you mentioned you'd do that in due time... so yeah, nothing to pick on here. Not even an un-deburred metal whisker.

Yea, it has been that long!! I couldn't believe it either....I think it's one of the reasons I really wanted to button this one up. I walked in this morning and saw my development table empty, it was a good feeling....then to look over and see this in working state in the rack, even better!!

I thought of that too....but I don't really know of any games that I play that would tax it.... Unreal Tourney and Q3A wouldn't bother this PSU a bit!

I need to fix you up with something then.

Yes if you don't mind.

OK, the mouse has model #: M-UK DEL3. Its OEM is Logitech and it uses a custom Logitech RTH0200 IC. It's a USB mouse... but I remember it came with a passive USB to PS/2 adapter (meaning, the internal mouse's IC is compatible with either USB or PS/2 protocols and switches on the fly.)

It's always good to know someone is watching.....but you contributed the SBC; which will be utilized to run the master controller. It was shown earlier in the thread.

Ah, right.
So now you have a [legacy] piece of Washington D.C.'s airport toll road in your project. (road's name omitted so as not to come up on search engines.)

Absolutely brilliant! I didn't even think of that.... Perfect duty to add to the list, especially for all the retro stuff!

20 years ago, this thing could keep up, I'd have needed atleast 4 of them. Back in those days, it wasn't uncommon to have 5+ boards strung out across the bench, testing & burning in. Doing them one at a time would have been agonizing slow.

I suppose your repair shop was popular / well-known. I don't think there was anyone like that here in the area. Then again, the early 2000's is when I was just getting into PCs and PC building / hardware (as a hobby), so I may not know any better.

I spent my whole career poking them with screwdrivers.....yea, I know....horrible habit to fall into....and I cringed at myself all hte time for doing it....but I still did it. Now I can do it the right way!

LOL.
I get sweaty palms and nervous every time I hold a big metal object above a motherboard. It's not like I've killed one this way or dropped whatever I was holding. But just the thought of it gives me chills.

Yes, I braided the mains...and added ferrite beads. I was worried that intermixing the mains (AC) in close proximity to the VGA cabling that it may cause some interference issues with the VGA transfer switches. This has not been an issue; but I can not confirm if these precautions were the reasons why not.

Well, it's a good practice at the very least.

My grandfather was a doctor....everyone tells me based on my sloppy writing that I should have followed in his footsteps!!

Technically you did / are - your patients are just not humans.

I think it'll be ok....atleast for now. It would be nice if it had the full range of the slides, which would have it coming out a good 3 feet; which is why the diskwashers went under instead of above....want to keep it bottom-heavy.

The only thing about extra-long slides - you might have to brace the cabinet to the wall to prevent it from tipping forward. But looks like that may not be the case now... especially with a bottom-heavy design.

I don't think it would. PS2 KB is what triggers the port....like I said before, KVM is still an open issue in some instances with this....fortunately, most board still do have PS2 ports....but some don't.

I wonder if one of these would work then:
https://www.ebay.com/itm/313578860222

Like I mentioned, I have 2 of these. They do work well overall. My only complaint is I can't use them for gaming - any held-down key on the KB is dropped / deactivated after 2-3 seconds and so needs to be pressed again to become active again (i.e. if I hold the "W" key to walk forward in an FPS game, after 3 seconds the adapter would release the key and I have to release and press "W" again to activate it again.) Apart from that, the adapter does what it's designed to do.

That is what I am afraid of; 'high school v2.0'. I wouldn't do well in that environment at all. I like to clown around as much as everyone else....but in that kind of environment, my 'get-er done' mentality would be hindered and I'd get aggravated quickly...when my mind is focused on something just to have it 'taken out of character' by others acting like...well....highschool kids.....I tend to be short-tempered. Probably not a good combo for a classroom.....

Well, by HS 2.0, I mean that in some universities, the professors may treat the students as if they are HS kids. That's how the 1st place where I went to was - acting as if we all had no life other than college/university... which is not how it may be for everyone. The 2nd place I went to, due to the large # of military and older folks we had there, the professors actually understood if someone needed accommodations due to having a job, family, or other responsibilities besides university work. So it was a different (and a lot more professional) treatment.

It serves a few purposes....sometimes I'll look back on my own builds for reference material for another one I'm pondering...sometimes it's bragging rights (not many of those really, in modern terms I tend to buy 'trailing edge' tech)....but whatever the reason, if someone gets something useful from one of these threads; mission accomplished!

Well, I also consider it a form of entertainment that is very uplifting / inspirational, especially when it details the process like you normally do.

The ferrite collars/beads came from the sustain board harnesses from an old Plasma TV....those give off so much EMI, I knew there would be a bunch in there... I tend to fix Plasma's, I like them.....but this one had a cracked screen.

I scrapped two over New Year's this year. Both were from a dumpster of a thrift shop. Both had a few bad caps and cracked screens. I'm not sure if they were thrown in the dumpster because of the cracked/bad screen or if that was a result of them getting thrown in the dumpster due to not working due to the bad caps... but either way, they were not fixable at this point. One was an LG-built Visio plasma and the other a more modern (probably 1080p) Panasonic plasma. Both were 50" or 55", IIRC. I'm pretty sure the Visio must have been due to the bad caps. A family friend of ours gave me a Philips 50" plasma that he said works but no one wanted. My intention was to give it away right away, since I don't watch or need another TV... but once I got it home, I found out it didn't work. Was just doing the blinking light on me. Opened it up and, surprise! - 1 bulged cap on the 3.3V rail. Replaced that and it's back up and running. Was going to donate/give it away, but noticed its label says "Made in Belgium" and its analog inputs are multi-system (handy for watching old analog content overseas, if I ever do.) Plus, I've tucked it away and don't really feel like moving it again. It's 170 lbs. I can't even put it on a stand by myself.

As a rule, I am too....but on one like this; where it's taking a long time to build, I find myself grabbing my notes & drawings and writing other data on it....and before I know it I've got the notes for 7 different projects on the same pad.....creates confusion......so the whiteboard won.

Yup, I'm guilty of that. Can't have a piece of paper go to waste with space on it that's not written to. Then I look at it some day much later and I can't even figure what's what.

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

I doubt anything that serious would happen. Of course, with Putin being how he is, no one can be certain 100%.
...
And yeah, I'm also not super-thrilled about moving there either. But it's been set in motion already. No biggie, though - I can always come back here if I can't make it there. I just won't be coming back to the same area where I am now. I just can't afford it. Never could, actually. So this has been brewing for many years. But anyways, I'll cut it short here with that.

Well, just stay in contact.....and keep your wits about you...

Nothing to critique, though.
Well, reading through the posts, at some point I though I'd mention I'd be nice to put some labels on the switches and lights... but noticed later on you mentioned you'd do that in due time... so yeah, nothing to pick on here. Not even an un-deburred metal whisker.

The labels for switches & lamps is intended to be done with my wife's cricut....which may be bit of a challenge as small as they are....but one way or anotehr it will get done.... I know what all the switches & lamps are for....but I did make some quickie labels for the ammeters, as for some reason I kept catching myself always glancing over at the whiteboard for their orientation....

OK, the mouse has model #: M-UK DEL3. Its OEM is Logitech and it uses a custom Logitech RTH0200 IC. It's a USB mouse... but I remember it came with a passive USB to PS/2 adapter (meaning, the internal mouse's IC is compatible with either USB or PS/2 protocols and switches on the fly.)

Filed into my firmware....and I'll kick this around.

Ah, right.
So now you have a [legacy] piece of Washington D.C.'s airport toll road in your project. (road's name omitted so as not to come up on search engines.)

Yep, that would be the one. It's in a different case. Look through the thread, it may have been done during your hiatus.

I get sweaty palms and nervous every time I hold a big metal object above a motherboard. It's not like I've killed one this way or dropped whatever I was holding. But just the thought of it gives me chills.

I got used to it after a while....you'd be amazed how quickly and nonchalantly you could stab PWR_ON pins and barely even look at it....

The only thing about extra-long slides - you might have to brace the cabinet to the wall to prevent it from tipping forward. But looks like that may not be the case now... especially with a bottom-heavy design.

...and the rack *empty* is VERY heavy....but fastening it to the wall has been considered if it could even remotely tip. I do think I will eventually modify the posts when everything is in a permanent state...but for right now it's doing just fine the way it is.

Well, I also consider it a form of entertainment that is very uplifting / inspirational, especially when it details the process like you normally do.

I have to confess, I enjoy teasing with lack of details going in.....but if you want to be taken seriously at all, in the end you have to give up the secrets... I'm not protecting anything I'd ever patent; so I have nothing to hide.....if someone wanted to ever attempt to make something like this, I could care less if they used/copied any of the information I posted.

Ok, now here's where it gets fun (atleast for today) and testing your theory of PSU matching. That was an absolutely brilliant idea....here's a great example of hardware from an era of transitional between 5V heavy and 12V heavy....but having the +12V EPS connector, I'd guess and say 12V heavy. I rescued this on ebay; I didn't buy it with any specific build or plans in mind for it other than maybe some kind of weird retro gamer at some point....it was just cheap, and a bit of a rare / unusual board.... It came with CPU's, RAM, and Heatsinks. Bad caps of course and the chipset heatsink had some oddball cobbled on it....odds are the original fan had failed and the owner rigged it up.....

Asus K8N-DL. I already removed the goofy heatsink from the chipset. Still needed to be recapped.



The replacement heatsink / fan I robbed off a bad Supermicro SKT-F board I had.



Recapped and the HSF was a perfect fit!! Low profile, so a GPU won't interfere with it. Nice ball bearing fan.



The 'rigged' heatsink that was on it when I got it.....



...and ready to be tested...





In 'the oven'....



So far so good!





Sitting idle pulling 8A off the 12 EPS rail and ~4A off the 5V rail and 5A off the 3.3V rail.



Testing utilities had it yanking 10~12A off the +12V EPS rail, 5~8A off the 5V rail. The 3.3V rail stays steady @ 5A. The 9800GT held steady @ ~3A, as I didn't do anything that taxed it.



While I'm not done diddling with this one yet, the takeaway is it's a 12V heavy board, but it did tug its share off the 5V rail as well...this board is from 2005....but the point being, watching the loads across various rails is a great way to pair it with a PSU and it's ratings per rail. Some boards it's hard to tell and it's a bit of trial & error. This idea took the guesswork out of it. So put this down as contribution # 2 for this project for you!

[sam_sam_sam]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

………> this board is from 2005....but the point being, watching the loads across various rails is a great way to pair it with a PSU and its ratings per rail. Some boards it's hard to tell and it's a bit of trial & error. This idea took the guesswork out of it. So put this down as contribution # 2 for this project for you!

I like the fact that you see what every power supply rail is doing in real time
To me this is a real plus for your project or it would be for me

I have a question for you about what would be a good switching power supply would be good to test the majority of motherboards as a general rule for the sake of argument

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

I like the fact that you see what every power supply rail is doing in real time
To me this is a real plus for your project or it would be for me

I have a question for you about what would be a good switching power supply would be good to test the majority of motherboards as a general rule for the sake of argument

For the TPU, I simply stuck with the PSU that came with the Dolby unit. It's an EMAC's 550W redundant. These units are always under-rated, as they are made to 'sprint' at full load while running on ONE module; load balanced in the backplane...so they're capable of sustaining at least 1.5x their rated load. I stuck with it not only because of it's power ratings, but it fit the case (made one thing about this project easy). To answer your question though, this PSU is heavy on all key test rails (+12V, +5v, and +3.3V); every rail is 30A or greater. ...and these units are very high build quality. Another factor; which plays into the 'it fits the case' category....If a module actually fails, it can be ejected and repaired/replaced from the outside, I don't have to completely disassemble the unit; cutting wires ETC to fix it. If the IPU failed OTOH, that would be a real pain, but nowhere near the disaster it would be to have to replace the TPU; with all the connections to the shunts. I did recap the IPU, and it's not under much load at all....the odds of its failure would/could/should be slim (knock on wood).

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

There is only one function that has not been formally tested yet....and that's the AT motherboard using the override. I'm positive that AT board testing will prove to function just fine, but it does need to be properly tested & verified. The override has been used several times; it is handy for testing an ATX motherboard that will not power up when the PWR soft-on is triggered. When this happens, trip the override switch, which will power up the board. It won't POST, but you can measure things with it running. In testing (the original SKT-A board), tripping the override, it would actually POST & run...

Anyway, no AT board has been tested in this yet; as I have no AT boards around that aren't in use that I know work. I looked for just the right board...a unique tester and something I can do a retro build with later....and I found one! A Supermicro P6DKF FULL AT dual slot-1. Found it cheap. This is the full AT, not a baby AT. After buying, it dawned on me that it may not even fit in the 'oven'....but I do have a case that can take one of these. This board is circa 1997; FX chipset, supporting only 2.8v P2's (Klamath core). It comes with a pair of 266's, but I happen to have a known good pair of 300's here....that is the fastest this board could take, as the 333 is a Deschutes. This will be the final test for the motherboard tester!

The 'oven' as this has been so nicknamed has been used pretty much daily since being installed in the rack; for my stuff a little and quite a bit of customer recapped stuff.

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

Here was a real power sucker random test subject; another cheap ebay rescue I bought ages ago, mainly for the Dynatron coolers on the CPU's...I paid less for the entire combo than the normal price of one of those dynatron heatsinks. This is another AMD system; dual skt-f w/ 2x Opteron 2222 SE's @ 3GHz...





Sitting idle....



Running memtest...there were a couple tests where the EPS 12V rail broke 15A!



These CPU's are only the dual core santa rosa's....I envision the quad or hex shanghai's being even greedier. Only 2 memory modules as well. Apparently the 2393/8393's are impossible to find now....I already have 2 pairs of them in other builds....but I'm not taking either of those apart.... I remember buying 4 of the 8393's a few years ago (fastest quadcore shanghai), and they were crazy cheap!! Now, they're nowhere to be found! Weird, didn't think there's really be much demand for them...so I guess this board won't get any 2392's or 8393's.

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

...and the final test for this project... I won't say perfect, as a clearance issue came up with a full AT size board. This would not be an issue with a baby AT (what pretty much all AT boards are).

By rule, an 'AT' board is AKA a 'FULL AT'. The more common ones were 'baby at'; but just became known as 'AT', even though that was a bit of a misconception. Anyway, an 'AT' (or full AT if you still prefer) is the physical size of an eATX, but there's no such thing as an eAT or Extended AT....so that'll conclude our lesson of the AT form factor....and onto this big ass board!!





Sitting next to an eATX.



It POST's! I had already tested the override...but now it's been officially tested in this format; testing an AT board....which was the original intent of the override.



+5v draw at idle. This board draws from the +5V rail only.



Now here's where the clearance issue came into play. Being AT, it uses an AT keyboard. I tried to use the PS2 keyboard with an adapter....but that was too long and the board was hitting the front IDE & floppy utility housings and not clearing the fan grilles in the rear, so I simply had to use a real AT keyboard....and even then it was a close shave! This would not be an issue with a baby AT, as it would be shorter and narrower, allowing clearance with the adapter by a couple inches easily.



This was also the first time I used the floppy function of the machine, worked without a hitch. I had to update the BIOS; as it was running v1.0.....I'm sure that couldn't be good. Supermicro still had the BIOS for this in their archive; version 1.8d.



Completely changed the BIOS interface from the old AMI with a mouse to this....



Running 'trohbleshooter', it started pulling a bit harder off the 5v rail. It got close to 18a a couple times.



I do have a beautiful heavy-iron early 90's AT case that will fit this that currently has a 486 DX4 @ 100MHz in it....I was never a 486 buff, so I'll definitely yank that for this. This is running a pair of P2 266MHz CPU's with 256mb RAM. I have a pair of 300MHz Klamath's for it, the fastest it can take..but that's for a different thread.

The testing phase of 'the oven' is now complete!

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

The burning question answered....how big of a power hog is a Netburst-era CPU.....

The test subject is a Supermicro X6DAL with 2x Irwindale single cores @ 3.8GHz





12A off the EPS (CPU Power) sitting completely idle (BIOS screen).



memtest... had it consistently @ 15~16A



Prime95 had it as high as 18A.....

...and now you know why these can double as space heaters!!

[TechGeek]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

If that's Netburst, I'd love to see how much power an S478 or S775 Prescott would draw.

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

If that's Netburst, I'd love to see how much power an S478 or S775 Prescott would draw.

Probably slightly above half that; as Prescott is pretty much the same core as Irwindale....and this test was with a dual board. I don't have a prescott that's not in use to verify that though....but my guestimate would be in the 8~10A at idle.

[TechGeek]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

probably slightly above half that; as prescott is pretty much the same core as irwindale....and this test was with a dual board. I don't have a prescott that's not in use to verify that though.

10-4

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

Testing a Dell GX745 that had been freshly recapped....I don't see these much anymore....but I got one for repair....and the only form-factor that hasn't been 'officially' tested in the 'oven' (besides outright proprietary); the BTX form-factor.

Because it's the weird BTX layout, had to use the standoff slats to test it.



Cookin'



Draws... The CPU was a single core LGA775 Celeron....don't remember the speed....but it wasn't heavy in the power department.



Now I can say that every common form-factor type has been tested in this machine!!

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

You know what you can use this machine for - matching an old PC motherboard to the "right" PSU for most balanced voltage operation.
E.g. socket A boards tend to use the 5V rail... so seeing how much one draws and then matching that with a 12V-heavier GPU, you can use even a crappy PSU with terrible voltage regulation, and still get very nicely balanced voltage out of that.

Here was one today that surprised me...and it takes a little doing to accomplish that these days.

The board in question is an Asus P6X58-E WS LGA1366 motherboard. I've had it a while....was just not sure what I wanted to make out of it. Something came to mind but I needed to verify functionality; as I need to buy some RAM for it....and didn't want to spend the $25 bucks on the memory if the board didn't work. It only has 6gb in it, I wanted to max it at 24gb; the most the X58 can run.



Here's where I was surprised.....get a load of the draw on the 3.3v rail and how much isn't being drawn from all the others. I figured this would be a 12v heavy board, most of this species are......



All it was doing was memtesting the existing RAM....



So again, that was a fabulous suggestion and something I've paid attention to with builds for motherboard versus power supply specs. A board that's so 3.3v heavy, I will watch the PSU selection closer and make sure it has a hefty 3.3v rail.

That's one other weird thing I've found to be helpful when powering up boards with this, various draws on all rails prior to actual POST. If it's a dud board or there's a POST issue, a draw will go to a point (or stay on or close to zero) and just stay there. A board attempting to POST, you can watch fluctuations in draws prior to POST as things are 'turned on', and shazam, it comes on...if it doesn't you do the usual things to eliminate stuff, but with every power cycle, watch for changes in behavior....this has speeded up troubleshooting on more than one occasion of a no-post situation that wasn't the fault of the motherboard.

FWIW, 'the oven' has 294 hours on it now. It is used frequently.

[sam_sam_sam]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

I can see how and why you like using your creation if you are doing a lot of computer building or troubleshooting I can see how this would be very helpful l pay close attention attention to this post for inspiration on how to use some of what you have here in this post

I have one question for you do you think digital meters would do the same exact thing that you are doing here with analog meters that you use are using and if not where did you get those analog meters from and are they still available

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

I have one question for you do you think digital meters would do the same exact thing that you are doing here with analog meters that you use are using and if not where did you get those analog meters from and are they still available

That's a good question and something that was taken into consideration during the design stage of this. The reason I went with analog meters is because subtle fluctuations in readings can be missed by digital metering versus analog; IE they won't refresh fast enough....and in the case of this machine, these fluctuations can be critical at times and would be missed if digital meters had been used.

[sam_sam_sam]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

Now where did you get the analog meters where the voltage and current meters are the same physical size and the same dimensions

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

Now where did you get the analog meters where the voltage and current meters are the same physical size and the same dimensions

They came from ebay. I'll see if I can find the vendor. Their quality is good and they are accurate.

[sam_sam_sam]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

They came from ebay. I'll see if I can find the vendor. Their quality is good and they are accurate.

Would these meters be accurate enough for this purpose for a battery charger monitor for 21700 battery cells

https://www.ebay.com/itm/401723265510
https://www.ebay.com/itm/371863979615
https://www.ebay.com/itm/401274655779 —> ( this one is going to be used for charging and discharging and being able to use the same meter )


I would be appreciate if you could find the eBay seller that you got them from thanks

[Topcat]

Re: The (now the death of) Dolby DP600 Build (BEYOND COOL BUT PIC HEAVY)

Would these meters be accurate enough for this purpose for a battery charger monitor for 21700 battery cells

https://www.ebay.com/itm/401723265510
https://www.ebay.com/itm/371863979615
https://www.ebay.com/itm/401274655779 —> ( this one is going to be used for charging and discharging and being able to use the same meter )


I would be appreciate if you could find the eBay seller that you got them from thanks

That is the vendor mine came from. I remembered the name once I saw it. I never had a problem with any of hte meters as far as function & accuracy.