Thread Tools
Dec 01, 2015, 12:03 PM
Registered User
Ken,

No problem with the charge readings; we all do it more as we get older so I check and check and still get it wrong!

Re temperature measurement, I agree about infra red meters; I gave up as various pack surfaces have different emissivities so I tried using a probe but it was round and about 3/16" diameter so it did not make good thermal contact and had significant thermal mass so it lagged the temperature.
I finally finished up with these which are ideal as they have virtually no thermal mass and can be sellotaped to the battery.

http://www.rapidonline.com/Electroni...rmistors-61185

Wayne
Sign up now
to remove ads between posts
Dec 01, 2015, 12:58 PM
Registered User
Wintr's Avatar
If you want better repeatability with taped on probes, a dab of grease under the probe will eliminate any air gaps between the probe and the surface; doesn't take into account any gap between the covering and cells within, of course, which may be the true source of the variation, not the color of the wrapping. Although, some colors of the wrapping may also indicate a film that lays down better than other colors.
Dec 01, 2015, 01:48 PM
Registered User
Ken Myers's Avatar
I retracted my 'color statement', as it was a 'rush to judgement' on my part. Besides having three different colors, they were three different capacities, duh, thus three different masses!

I measured them all later in the day, after they were 'cold soaked' longer in the basement and all were the same 16ºC.

Good tip on the grease. The probe end is just a bare wire on the unit I'm using. It lays down with tape very well against the 'side' covering of the middle cell.

The unit I'm using is a Signstek 3 1/2 6802 II Dual Channel Digital Thermometer with 2 K-Type Thermocouple Sensor Probe for BGA rework HVAC 1300°C 2372°F
http://www.amazon.com/Signstek-Chann.../dp/B00FFYEPVQ

It will actually measure in two places with the two probes. I would think it should be available in the UK and the rest of Europe as well.
Dec 01, 2015, 06:26 PM
Registered User
Wintr's Avatar
Silicone grease is a good choice, as it is known to be non-conductive; important for bare thermocouple probes. There are other, better choices that are better heat conductors, but less commonly available.
Feb 15, 2016, 10:05 AM
Registered User

ESR meter and Graphene batteries??


Wayne, I have your 1-6S, 500-10,000mAh unit and absolutely love it - THANKS! I just received some of Turnigy's new Graphene batteries and decided to test one of their 4S 1300mAh packs side-by-side with one of their Nano-Tech packs (also 4S 1300mAh).

When testing the Graphene pack, your meter gave me the pack results fine, but when I tried the cell readings, it only gave me the cell voltage and IR, not the alpha or maxI readings. Any ideas?
Feb 15, 2016, 10:11 AM
Registered User
Ken Myers's Avatar
Did you set the battery capacity?
Feb 15, 2016, 10:27 AM
Registered User
That was it, thanks. I set it on the first battery, and forgot on second. Dumb move on my part.
Feb 15, 2016, 10:42 AM
Registered User

Turnigy Nano-Tech vs. Turnigy Graphene


Both batteries are 4S 1300 mAh.

Nano-Tech, rated 25/50C
Pack ESR - 41.7mOhm.
Cells: a23C, maxI=30.8A, 7.80-7.96mOhm
Graphene, rated 65C (no max rating seen)
Pack ESR - 26.7mOhm.
Cells: a33C, maxI=44.0A, 4.00-4.28mOhm
Based on the meter's assumed safe discharge rate of 6W/Ah (that's what I remember reading was the basis for Wayne's calculations), the Nano-Tech's rating of 25C and the meter's calculation of 23C, seems reasonable. However, there seems to be a discrepancy between the Graphene's 65C rating and the the meter's 33C calculation (approximately 1/2). Maybe this means that the 6W assumption for conventional LiPo's doesn't hold for Graphenes? Or is the Graphene being over rated?

Now to run discharge curves on both at 1C and 25C and measure the post discharge pack temps.
Last edited by Triggerscan; Feb 15, 2016 at 10:56 AM.
Feb 15, 2016, 11:17 AM
Registered User
Quote:
Originally Posted by Triggerscan
Both batteries are 4S 1300 mAh.

Nano-Tech, rated 25/50C
Pack ESR - 41.7mOhm.
Cells: a23C, maxI=30.8A, 7.80-7.96mOhm
Graphene, rated 65C (no max rating seen)
Pack ESR - 26.7mOhm.
Cells: a33C, maxI=44.0A, 4.00-4.28mOhm
Based on the meter's assumed safe discharge rate of 6W/Ah (that's what I remember reading was the basis for Wayne's calculations), the Nano-Tech's rating of 25C and the meter's calculation of 23C, seems reasonable. However, there seems to be a discrepancy between the Graphene's 65C rating and the the meter's 33C calculation (approximately 1/2). Maybe this means that the 6W assumption for conventional LiPo's doesn't hold for Graphenes? Or is the Graphene being over rated?

Now to run discharge curves on both at 1C and 25C and measure the post discharge pack temps.
I think this is to be expected..

In real discharge testing I found that many 20C and 25C lipos were realistically rated and could really cope with that rate of continuous discharge rates.
I have discharged Turnigy Blue lipos rated at 20C at over 23C with no problem and an original GensAce 25C at 30C which was at its limit but OK.

The fiction starts at about 35 - 40C and the jokes at 65C, so that just halving all C claims is not a sensible rule of thumb.

It is a lottery but quite a lot of 20 and 25C claims are genuine but be suspicious of any claim of >35C.

Wayne
Feb 15, 2016, 02:49 PM
Registered User

Graphene batteries


Wayne, from what I've been able to research, one of the limitations on the discharge rate has to do with limiting the destruction of the silicon particles in the carbon/silicon anode and it's limited surface area (solid rod). Some of the recent advances have been to encapsulate the silicon particles in an one-atom thick graphene coating which keeps the particles intact even after they crack and also protects them from electrolyte damage. In addition, the graphene (which is conductive) also increases the effective surface area of the anode thus increasing it's C rating.

What I meant by the 1/2 is that when I measured the Graphene battery with the Wayne Gile ESR meter, it rated the battery as 33C (roughly 1/2 of Turnigy's marking of 65C). But remember, the ESR rating of 33C is based on a calculation that assumes a safe power generation of 6W/Ah. If the Graphene batteries can handle higher power generation without damage, that may explain the higher manufacturer's rating. The ESR calculation may not adequately handle this new technology, OR the batteries are being over hyped.
Feb 15, 2016, 04:06 PM
Registered User
[QUOTE=

What I meant by the 1/2 is that when I measured the Graphene battery with the Wayne Gile ESR meter, it rated the battery as 33C (roughly 1/2 of Turnigy's marking of 65C). But remember, the ESR rating of 33C is based on a calculation that assumes a safe power generation of 6W/Ah. If the Graphene batteries can handle higher power generation without damage, that may explain the higher manufacturer's rating. The ESR calculation may not adequately handle this new technology, OR the batteries are being over hyped.[/QUOTE]

I agree and the Graphene's lower IR will generate less heat. (I squared R) but assuming that the materials are aproximately the same specific heat, the temperature rise will be about the same for the same dissipation. The heat generated at 65C will be 4 x the heat generated at 33C so unless the materials can withstand a much higher temperature, I would guess that the realistic C is around 35 - 40C. I have upped it a bit as the unit weight/ Ah is a bit larger.

Wayne
Aug 12, 2016, 06:46 AM
Registered User
ESR METER – End of production

I have decided to give up making the ESR meter mainly due to advancing age.
I only made the first one for my own use and was surprised how well it worked so I offered it on RCG expecting to sell perhaps 10 or so and that was almost 6 years ago. It turned into a near full time hobby which I found interesting and which made me a small profit; an ideal retirement scenario!

Hopefully, if nothing else, they have enabled people to accurately measure and compare lipos and help to debunk some of those wild “C” rating claims which were so common a few years back.
I made them all individually and several people asked whether I got bored with making the same thing, but the answer is that every time I built one and it worked and calibrated correctly, I always felt a little surge of satisfaction.

I am making a final batch, almost complete, and have a few available in stock. I have also despatched a batch to ProgressiveRC in Seattle so they are available now.

I would like to thank all of those who have supported it by buying one and making positive comments on RCG and particularly David Gray of ProgressiveRC who immediately offered to sell them and has been doing so ever since.
Anyone needing service, repairs or advice can still contact me on RCGroups and I will try to help.

Thanks once again everybody,

Wayne
Aug 12, 2016, 07:01 AM
ancora imparo
jj604's Avatar
Wayne, I am sure many people around the world will be unhappy to hear this but I am also sure they would say you and Mark Forsyth made a very significant contribution to the practical understanding of model LiPo packs by your promotion of IR as as simple test of performance and provided the tool to prick the bubble of Unrealistic C rate Expectations.

I hope someone picks up the traces and offers to produce something as simple and elegant, but at the same time sophisticated, as your ESR meter. The HobbyKing ripoff of your meter might be convenient and cheap but it is no substitute.

I know I am not parting with mine!

Regards

John
Aug 12, 2016, 09:21 AM
Registered User
Ken Myers's Avatar
Quote:
Originally Posted by Wayne Giles
ESR METER – End of production
On no, say it ain't so.
Thanks so very, very, very much for such a useful tool!
Aug 12, 2016, 10:34 AM
Registered User
Wintr's Avatar
Perhaps the good folks at ProgressiveRC would consider having them built under license? It would be a shame to see such a great tool vanish from the market.
Aug 12, 2016, 04:32 PM
Registered User
icicles's Avatar
Quote:
Originally Posted by Wintr
Perhaps the good folks at ProgressiveRC would consider having them built under license? It would be a shame to see such a great tool vanish from the market.
Now that's a fantastic idea.
I've had my meter for, well since they first came out. I would not be without it.
Thank you for a sensational tool. It lives permanently in my tool box
I trust you will have a great retirement.
All the best

Chris

Sent from my SM-N910G using Tapatalk
Aug 12, 2016, 04:43 PM
Registered User
Nooooooooooooooooo! Say it isn't so Wayne!

Well, consider me a member of the considerable group of modelers who are incredibly grateful for your work on the ESR Meter and your tremendous contributions to the community as a whole. Through your tireless efforts and patient tutelage, we are now a LOT better informed and there's little doubt that your contributions are directly responsible for the continued improvement that we've witnessed in lipoly performance over the last several years!

Enjoy your well-earned retirement from ESR Meter production. Bravo sir!

Mark
Aug 12, 2016, 06:10 PM
Registered User
ggcrandall1's Avatar
Let me add my thanks for a great tool. As others have said, mine is always nearby for checking new packs and verifying older ones.

Glen
Aug 13, 2016, 08:55 PM
Frankenstein recycled packs
rampman's Avatar
I am a production supervisor. Just saying... It don't have to die. *wink*

Rick
Aug 14, 2016, 02:39 PM
Registered User
Thanks for all your kind comments.

I know the meter has been a useful tool, but it has been great fun developing it and making it and I only built it originally for my own satisfaction

I really believe that Mark and John have contributed as much, if not more than I to general understanding of lipos and bringing wild claims down to earth. We all co-operated to produce the "Lipotool" which brought some reality to lipo performance figures.

Wayne
Aug 21, 2016, 06:36 AM
ROV Pilot
jijohans's Avatar
Hi Wayne
Do you still have ESR meters for sale?
Best
Jim
Aug 21, 2016, 10:32 AM
Registered User
Quote:
Originally Posted by jijohans
Hi Wayne
Do you still have ESR meters for sale?
Best
Jim
Hi Jim,

Yes, although I have stopped making them, I still have a few left in stock.

If you want one send me a PM and I will return my e mail address to which you can send funds by paypal.
Price is still as per the first post on this thread.

Wayne
Sep 02, 2016, 10:53 PM
Mark Harrison
Quote:
Originally Posted by Wayne Giles
ESR METER – End of production

I have decided to give up making the ESR meter mainly due to advancing age.
I only made the first one for my own use and was surprised how well it worked so I offered it on RCG expecting to sell perhaps 10 or so and that was almost 6 years ago. It turned into a near full time hobby which I found interesting and which made me a small profit; an ideal retirement scenario!

Hopefully, if nothing else, they have enabled people to accurately measure and compare lipos and help to debunk some of those wild “C” rating claims which were so common a few years back.
I made them all individually and several people asked whether I got bored with making the same thing, but the answer is that every time I built one and it worked and calibrated correctly, I always felt a little surge of satisfaction.

I am making a final batch, almost complete, and have a few available in stock. I have also despatched a batch to ProgressiveRC in Seattle so they are available now.

I would like to thank all of those who have supported it by buying one and making positive comments on RCG and particularly David Gray of ProgressiveRC who immediately offered to sell them and has been doing so ever since.
Anyone needing service, repairs or advice can still contact me on RCGroups and I will try to help.

Thanks once again everybody,

Wayne
Thanks Wayne, I have learned so much about by using mine, not even counting the practical value.

Any chance of releasing the schematics / code to someone who wants to continue production?
Sep 04, 2016, 01:45 AM
Registered User
Quote:
Originally Posted by marhar
Thanks Wayne, I have learned so much about by using mine, not even counting the practical value.

Any chance of releasing the schematics / code to someone who wants to continue production?
Mark,

Thanks for the thought.
I am in the process of doing exactly that with a regular RCG member at present.

Wayne
Nov 15, 2016, 11:01 AM
Registered User
ESR METER - BACK IN PRODUCTION! (November 2016)

I gave up making the ESR meters three months ago but was immediately contacted by an RCGroups member who offered and, more important, wished to take up the mantle of producing them.
The member is Rick Distler, better known as "Rampman" on RCG and a regular purveyor of sensible and knowledgeable advice about Lipos.

Over the past three months I have passed over all the technical details, including circuit diagrams, component list, test and calibration procedures to Rick and he has been busy building and testing an initial batch of units.

I understand that he is now ready to start selling the meters again.
He is doing so with my full backing and I hope that he is supported by RCG members as some compensation for all the free advice and help he has given over the years. I will still be skulking in the background to help with any technical support if necessary.

Rick is based near Phoenix, Arizona which is better for United States customers where the bulk of meters are sold. I understand that he also intends to continue to support ProgressiveRC but no doubt Rick will be posting more detailed information shortly.

I wish him luck and hope that he gets as much satisfaction from making them as a hobby as I did.

Wayne
Nov 15, 2016, 11:27 AM
Registered User
YAY! Glad to know that Rick is continuing your legacy, Wayne! He's fantastic!

Long live the ESR Meter!

- Mark
Nov 15, 2016, 02:14 PM
Registered User
ggcrandall1's Avatar
Wayne,

That is great news. I don't think you could have passed the project on to better hands. Rick is the man. Thanks.

Rick,

Thanks for picking up the ESR project. It's good to know we will continue to have support, and especially here in the USA.

Glen
Nov 15, 2016, 02:47 PM
Frankenstein recycled packs
rampman's Avatar
Thanks Wayne and Mark. This slick little meter just can't die.
With that said I have ordered enough of most parts to build 1000 units. It is cheaper by the dozen and the only way I can afford to keep this going is if I have a little profit in there so it is worth my time. Neither Wayne nor I will get rich off of these but I am honored to continue enabling it's legacy.

I will also add that this little board has more 1% precision resistors than any of the boards that I build in my 9-5 job. (that is what I do) Every resistor but one very large one is 1% and to make my life easier and not have to match resistors down to 0.1% I ordered 5000 each of critical resistors (remember cheaper by the dozen). I had to order some 0.1% resistors off ebay to get me through until my reels come in and those I still have to match as the quality was not there.

The good thing is my original meter (Wayne's first revision), a meter that Wayne gave me 2 months ago as a sample to build to and all of the meters that I have hand built (9 so far) read the same IR.
Wayne is a perfectionist but that is what it takes to make this work. I had to pull some critical resistors and match them to get a certain value in series in order to pass Wayne's test.

Progressive RC will be my main outlet for these though I plan to market and sell outside of Progressive and not undercut their price as their margin is minimal as it is.

I am honored to keep this alive and can't thank Wayne enough for trusting me to build these going forward.

Rick
Nov 15, 2016, 05:08 PM
The unknown Targaryen......
turbojoe's Avatar
Hey, this works great for me. Rick is LOCAL!

I don't expect my meter to be needing anything anytime soon though.
Still, it's good to know that a local boy has taken over the reins from Wayne. Good on ya Rick!

Joe
Nov 16, 2016, 03:27 PM
House of Paine
weaser42's Avatar
Go rampman...almost makes me want to buy a second one
Nov 17, 2016, 09:28 AM
Frankenstein recycled packs
rampman's Avatar
LOL Kevin. Unlike chargers where 2 is always better than 1, other than having a different plug on the mains to avoid always swapping adapters I see no reason for anyone to have 2 of these...BUT I will gladly sell you a new one. LOL

Rick
Nov 18, 2016, 10:55 PM
Problems saying NO to new toys
Rick,

Got my meter today from your 1st build. Works great.... . You fellows will be
very happy with Rick's building skills.

I will be using it to test all my batteries. Thanks and keep up the good work.

John L.
Nov 18, 2016, 11:06 PM
Mark Harrison
Yippee, Great to see such a well respected community member take the reins from the master!

I've been fiddling with an external controller to make it more convenient to use... just a part-time work in progress, but it's actually usable in its present state.

Giles ESR Meter Automation (2 min 0 sec)
Nov 19, 2016, 04:57 AM
Registered User
Mark,

Great - I am really impressed with that as an interesting extension to the meter.

As a further automated extension you could step the search lead from cell to cell and program the operating relay to take readings in sequence so that all the information on each cell is displayed in turn. No problem with adding series resistance into the search lead; it will not affect accuracy.

I will try to find out if it is possible to extract the results from the PIC so that you might be able to produce a fully automated rig and display and print out results with a computer.

Wayne

Wayne
Nov 20, 2016, 01:07 AM
Mark Harrison
Wayne, thanks! It would be great to have a fully automated rig.

Here's what I was thinking for the relay circuit... basically two relays per cell, one for each probe wire. Does this look right?
Nov 20, 2016, 10:06 AM
Registered User
Quote:
Originally Posted by marhar
Wayne, thanks! It would be great to have a fully automated rig.

Here's what I was thinking for the relay circuit... basically two relays per cell, one for each probe wire. Does this look right?

Mark,

I have asked Phil Green who designed all the software for the meter about extracting the results but unfortunately the processor is fully utilised and has no spare processing power available.

BTW, when you say in the video that setting the lipo capacity is "troublesome" it must be borne in mind that I asked Phil if it would be possible to upgrade the existing meter to perform all the extra tasks I wanted using just a software update and without an extra button. Within those limtations, I was very impressed with what he came up with as I thought it impossible.

The sketch you have come up with looks fine. You could use 3x 2pole relays to save cost.
It is very important to ensure that the timings ensure that two relays can never be energised together as this would produce short circuits on the cells with dire consequences. In any case I would reccomend that you put a 10ohm resistor in series with each of the balance leads which will ensure that a cell is never shorted and will not materially affect the results.

Wayne
Nov 20, 2016, 04:14 PM
Hittin Gaps With D Gains
SteelRainSpo's Avatar
Thanks for keeping this meter alive sir, now how and where can I purchase one of these for my tests?

Quote:
Originally Posted by rampman
Thanks Wayne and Mark. This slick little meter just can't die.
With that said I have ordered enough of most parts to build 1000 units. It is cheaper by the dozen and the only way I can afford to keep this going is if I have a little profit in there so it is worth my time. Neither Wayne nor I will get rich off of these but I am honored to continue enabling it's legacy.

I will also add that this little board has more 1% precision resistors than any of the boards that I build in my 9-5 job. (that is what I do) Every resistor but one very large one is 1% and to make my life easier and not have to match resistors down to 0.1% I ordered 5000 each of critical resistors (remember cheaper by the dozen). I had to order some 0.1% resistors off ebay to get me through until my reels come in and those I still have to match as the quality was not there.

The good thing is my original meter (Wayne's first revision), a meter that Wayne gave me 2 months ago as a sample to build to and all of the meters that I have hand built (9 so far) read the same IR.
Wayne is a perfectionist but that is what it takes to make this work. I had to pull some critical resistors and match them to get a certain value in series in order to pass Wayne's test.

Progressive RC will be my main outlet for these though I plan to market and sell outside of Progressive and not undercut their price as their margin is minimal as it is.

I am honored to keep this alive and can't thank Wayne enough for trusting me to build these going forward.

Rick
Nov 20, 2016, 04:59 PM
Frankenstein recycled packs
rampman's Avatar
Either directly from me or Progressive RC. It is the same price from either.
If you go direct my paypal is
rampman@fmxramps.com

Rick
Nov 20, 2016, 07:41 PM
Hittin Gaps With D Gains
SteelRainSpo's Avatar
Quote:
Originally Posted by rampman
Either directly from me or Progressive RC. It is the same price from either.
If you go direct my paypal is
rampman@fmxramps.com

Rick
Thanks for the information buddy, I ordered from the Progressive Rc site since I needed a few more items, thanks again
Nov 20, 2016, 09:18 PM
Mark Harrison
Quote:
Originally Posted by Wayne Giles
Mark,

I have asked Phil Green who designed all the software for the meter about extracting the results but unfortunately the processor is fully utilised and has no spare processing power available.

BTW, when you say in the video that setting the lipo capacity is "troublesome" it must be borne in mind that I asked Phil if it would be possible to upgrade the existing meter to perform all the extra tasks I wanted using just a software update and without an extra button. Within those limtations, I was very impressed with what he came up with as I thought it impossible.

The sketch you have come up with looks fine. You could use 3x 2pole relays to save cost.
It is very important to ensure that the timings ensure that two relays can never be energised together as this would produce short circuits on the cells with dire consequences. In any case I would reccomend that you put a 10ohm resistor in series with each of the balance leads which will ensure that a cell is never shorted and will not materially affect the results.

Wayne
Indeed, maximum credit to Phil Green for doing the upgrade purely in software... I know that's not a high powered chip by any means!

I will definitely add the 10 ohm resistors. What's an appropriate wattage?
Nov 29, 2016, 03:18 AM
Registered User
Quote:
Originally Posted by marhar
Indeed, maximum credit to Phil Green for doing the upgrade purely in software... I know that's not a high powered chip by any means!

I will definitely add the 10 ohm resistors. What's an appropriate wattage?
Mark,

Apologies for long delay - I went away to calculate it, got distracted and forgot. Worst case would be 32W!! so I guess it would be better to use 1A fuses or very small resistors such as 0.25W which would just blow open circuit. Alternatively you could use resettable PTC fuses as long as the normal state is < 10 ohms. Simple fuses are probably best as it is a fault condition after all.

Wayne
Dec 13, 2016, 12:01 AM
Mark Harrison
Quote:
Originally Posted by Wayne Giles
Mark,

Apologies for long delay - I went away to calculate it, got distracted and forgot. Worst case would be 32W!! so I guess it would be better to use 1A fuses or very small resistors such as 0.25W which would just blow open circuit. Alternatively you could use resettable PTC fuses as long as the normal state is < 10 ohms. Simple fuses are probably best as it is a fault condition after all.

Wayne
No problem Wayne, parts are coming in and I'm getting ready for the next step.

I'll have an update in a couple of days!!
Jan 13, 2017, 08:05 AM
Registered User
Although I gave up making the meters some time ago and handed the production over to Rick Distler in the States, I have had seven requests for meters from UK and Europe so I decided (with Rick's agreement) to use up all my remaining components and make a final batch.

As a result I have a few meters available at £50 each + postage at cost. They are all the latest Universal version.
Rick has meters in production but is not yet geared up for export so in the short term I can supply them to most places EXCEPT the USA for obvious reasons.

Postal costs are:- To UK: £4.25, To Europe £6.50, To Rest of world £9.00.

If you want one, PM me and I will send payment details and e-mail address.

Wayne
Last edited by Wayne Giles; Jan 13, 2017 at 01:47 PM. Reason: Spelling!
Jan 13, 2017, 01:04 PM
Registered User
vollrathd's Avatar
Quote:
Originally Posted by marhar
Wayne, thanks! It would be great to have a fully automated rig.

Here's what I was thinking for the relay circuit... basically two relays per cell, one for each probe wire. Does this look right?
I don't like posting in someone thread, but, it so happens I've been working on this very thing the past months using electronic relays. Everything is working quite well. Absolutely no precision resistors are required for the IR measurements. 5% would be just fine. But I think the cost to build it will far exceed the ESR meter shown in this thread. The circuit board parts alone are around $65 or so.

Ref
https://www.rcgroups.com/forums/show...ircuitboard%21
Jun 29, 2018, 12:56 PM
Quadaholic
--Oz--'s Avatar
I tried testing some small Nanotech 2S 300mAH 35-70C brand new packs on the wayne IR meter and when testing total IR it works fine (~95mΩ). But while testing cells, I mostly get over range (9 out of 12 cells). A quick test on my accucell6 shows 43mΩ and 34mΩ, FYI, the accucell mostly reports higher mΩ over the wayne meter. I realize I have two adapters in line (but it works fine for total IR and the other 50+ larger 1300-5000mAH) packs I have tested. So for sanity, I made a xt60 to 2pin adapter and makes no difference.

Any suggestions?

For them wondering what the small 3V cell is attached to my xt60 to deans adapter, it's a way to keep the wayne meter powered between packs, so you don't have to hassle entering capacity every single pack, its simply a 3V cell, a diode and switch to turn on/off.
Jun 29, 2018, 01:39 PM
Registered User
Ken Myers's Avatar
You will find that very low capacity cells have to much IR to be measured on this meter, or I should say you found that out.
Jun 29, 2018, 02:45 PM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by Ken Myers
You will find that very low capacity cells have to much IR to be measured on this meter, or I should say you found that out.
The IR meter says 100 to 10,000mAH. The guys flying these micro quads are pushing the limits and these are the batteries they recommend, a smaller 100mAH battery/cell is going to have higher resistance than this 300mAH cell. Or do you know of better 300mAH 2S batteries?

Am I right at the limit of ~35mΩ max per cell for this meter or?
Jun 29, 2018, 03:23 PM
Registered User
Ken Myers's Avatar
Quote:
Originally Posted by --Oz--
The IR meter says 100 to 10,000mAH.
I thought that it was 500mAh to 10,000mAh. That is what is printed on the face of the meter.

Oh wait! I just checked the photo of your meter. It does say 100mAh. Interesting. I have no idea how it could ever check 100mAh cells as they'd always be over range.
Jun 29, 2018, 05:42 PM
Registered User
I think the explanation here is that there are two versions of the meter. The “Analysis Meter” only measures 2-6 cells and uses a pulse of 16A which is too large for a very small 100mAh cell. The final version of the meter measures 1 - 6 cells and uses a pulse of 8A so that it can measure cells as small as 100mAh and has an internal battery enabling it to measure single cells. This is the “Universal Meter”.

Both meters will measure cell IR values up to 35m.ohms and will then read over range. If you are reading a single cell, you can only use the ”Pack” mode (as there are no balance connections) which will read up to 250m.ohms but that includes the connector and lead resistances which are competely eliminated in the "Cell" mode .

Wayne
Jun 30, 2018, 04:39 AM
Registered User
Bill Glover's Avatar
I did Wayne's 'approved mods' to my original meter to add an external power input for 1 cell pack testing, and a 'x10' switch which helps with measuring higher IR on very small cells.
Latest blog entry: Eachine QX65 FPV quad review
Jun 30, 2018, 10:49 AM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by Wayne Giles
I think the explanation here is that there are two versions of the meter. The “Analysis Meter” only measures 2-6 cells and uses a pulse of 16A which is too large for a very small 100mAh cell. The final version of the meter measures 1 - 6 cells and uses a pulse of 8A so that it can measure cells as small as 100mAh and has an internal battery enabling it to measure single cells. This is the “Universal Meter”.

Both meters will measure cell IR values up to 35m.ohms and will then read over range. If you are reading a single cell, you can only use the ”Pack” mode (as there are no balance connections) which will read up to 250m.ohms but that includes the connector and lead resistances which are competely eliminated in the "Cell" mode .

Wayne
As can be seen in my picture, I have the newer version (I just bought it a couple months ago). The batteries I am testing are 2S 300mAH 35-70 nanotech and are brand new, never been flown, only lightly cycled 5 times. So if I am in cell mode, max mΩ is 35 that this meter can read. I am logically thinking, 200 and 100mAH packs are going to be higher IR. Since my batteries are new and I can only read IR on 3 of the 12 cells, I am thinking I cant read 100 or 200mAH cells at all. Or there must be better batteries (lower IR) in this 100-300 category.

Quote:
Originally Posted by Bill Glover
I did Wayne's 'approved mods' to my original meter to add an external power input for 1 cell pack testing, and a 'x10' switch which helps with measuring higher IR on very small cells.
I added the external power with the battery , switch and diode. What is the x10 switch? tia
Jun 30, 2018, 01:38 PM
Registered User
Bill Glover's Avatar
Quote:
Originally Posted by --Oz--
I added the external power with the battery , switch and diode. What is the x10 switch? tia
It's a low current setting that effectively makes the meter dual range. With it switched on you need to multiply the displayed ESR value by 10. See here:

https://www.rcgroups.com/forums/show...&postcount=364
Latest blog entry: Eachine QX65 FPV quad review
Jul 03, 2018, 05:21 PM
Registered User
Quote:
Originally Posted by --Oz--
As can be seen in my picture, I have the newer version (I just bought it a couple months ago). The batteries I am testing are 2S 300mAH 35-70 nanotech and are brand new, never been flown, only lightly cycled 5 times. So if I am in cell mode, max mΩ is 35 that this meter can read. I am logically thinking, 200 and 100mAH packs are going to be higher IR. Since my batteries are new and I can only read IR on 3 of the 12 cells, I am thinking I cant read 100 or 200mAH cells at all. Or there must be better batteries (lower IR) in this 100-300 category.
Oz,

Apologies for delay; have been away.

You are correct in your assumptions so that you are somewhat stuck with the 35m.ohm limit on cells or having to use the Pack mode which includes the leads and connectors.
The 35m.ohm limit is brought about by the need for resolution and accuracy. To increase it would compromise both these and unfortunately the measurement of very small cells is a victim of this. At the other end of the range the resolution of 0.04 m.ohms is 2 - 3% of the possible cell IR of the best large lipos.

I thought I could offer a part solution by suggesting a precision splitter across the cell with the sense lead just looking at 50% of the voltage step so that you could double the reading up to 70m.ohms. I tried it today and it works in principle but , of course, which I had overlooked, it also halves the cell standing voltage so the meter locks out on “Cell Voltage <3.2V”

Probably the best compromise is to measure in Pack mode, taking care to use the shortest leads and minimum adapters in series and keep the contacts clean when measuring. The connectors used on the lipo have a resistance per contact of 7m.ohms and the XT60 about
1 m.ohm per contact so you can allow for them in the reading with some loss of accuracy.

Wayne
Jul 03, 2018, 05:43 PM
Quadaholic
--Oz--'s Avatar
Quote:
Originally Posted by Bill Glover
It's a low current setting that effectively makes the meter dual range. With it switched on you need to multiply the displayed ESR value by 10. See here:

https://www.rcgroups.com/forums/show...&postcount=364
Thanks!

I opened up my meter and its a different pcb layout, mine is Rev E, R22 is the very bottom right top left (picture got flipped) resistor.

So the stock discharge current on mine is 8.0A (1st waveform picture):
so it takes 90Ω across R22 to give 10x range, this is 800mA discharge (2nd waveform picture) ,
or 790Ω to give 2x range, this is 4A discharge (3rd waveform picture).

Its best to use multi turn trimmer pot(s) and just dial in to get the correct reading (EG: if normal range reads 6.50mΩ, then adjust pot for 10x to read 0.65mΩ, or 3.25mΩ for the 2x scale). By using the pots it takes care of tolerances and is just easier.

A simple SPDT center off switch will give you 3 ranges (10x / 1x / 2x).

This is for information ONLY , do not try this at home, use at your own risk.

Thanks for all your help guys!

EDIT: Added pictures of the installed pots (1K and 500Ω, I did not have a 100Ω, but it works fine), I gooped them to the pcb. Outside is a three position switch for 10x / 1x / 2x ranges (800mA/8A/4A discharge load).
Last edited by --Oz--; Jul 12, 2018 at 04:28 PM.
Jul 04, 2018, 07:00 AM
Registered User
Bill Glover's Avatar
Yup good advice, my "10x" value is close but doesn't exactly match the standard range.

Good enough for simple comparative testing though, IMHO
Latest blog entry: Eachine QX65 FPV quad review
Sep 06, 2018, 10:21 AM
Don L.
I'm looking for some wisdom from the ESR gurus.

I recently tried ThunderPower ProliteX 25c 6S 4400mAH packs on my hexacopter and experienced much shorter endurance than I was used to with MikroKopter 35C 6S 4500mAH packs - way more than the 100mAH difference in capacity would account for. For the record, I fly with 2 packs in parallel.

ESR of the new ThunderPowers is consistently around 8mΩ per cell, while on my old MikroKopter packs, it is around 5mΩ per cell. The measurements were taken from batteries that I had charged 2 days before and that had been stored side-by-side, so were at the same temperature, ~ 72°F.

The ESR meter reports true Cs that are about half the published C ratings for both, 12C and 17C. The flight logs show that the maximum current draw on either battery pack was less than 25A (50A for the pair).

I also checked some older 25C 6200 mAH Quadropower packs and found the ESRs to be less than 4mΩ per cell, with true Cs of 15C.

What is a reasonable ESR for a 25C (rated) cell, or any cell for that matter? Do higher capacity cells exhibit lower ESRs? Do these test results indicate that the ThunderPower batteries are inferior?

Thanks for any of your thoughts.

-Don
Sep 06, 2018, 01:09 PM
Registered User
Bill Glover's Avatar
Yes, in general ESR decreases as cell capacity goes up.

Shorter flight times are more related to capacity than C rating (or ESR) though. If you are using voltage monitoring to determine when to land you will need to lower the trigger voltage(s) for a pack that has a higher ESR (because the voltage drop under load is higher). But using a current sensor and having a primary alarm based on mAh used is a far better system. You need to validate the actual capacity of course, e.g. based on mAh put back in when you charge.

I use mAh used, plus a flight timer, plus an alarm based on the lowest individual cell voltage "just in case". Belt & braces
Latest blog entry: Eachine QX65 FPV quad review
Sep 06, 2018, 02:27 PM
Frankenstein recycled packs
rampman's Avatar
Don, what you found out is what Joe first noticed back in 2012. The Thunderpower packs are not what they used to be and are now in the lower tier of suppliers when it comes to true C ratings (higher IR).
Quote:
Originally Posted by MCSGUY

THUNDER POWER trades on their past glory and in large part is responsible for the spread of bogus C ratings. At one time they labeled their 6S/5000 for Continuous 325A output even though their split pack connector always (everytime) de-soldered at half that. I assume they rely on "Ignorance is Bliss 20C users" who believe TP is the "best" and are willing to pay the big bucks for the illusion.

5 years of testing has firmly established Thunder Power as a lower tier supplier, usually ranking in the bottom third in all test metrics. Their consistent failure to match the voltage between the 3rd and 4th cells on their 6S split assembly bears some responsibility (Ref. Reports 376, 417, 585, 653, 3212, 3520, 5404 and 5405). The "80C" Rampage tested well at 25C based on reasonable life expectancy. It will marginally handle 35C applications.
Competitively this pack should sell for $140 at most.
Read post #1 for his comments on these packs and others.
https://www.rcgroups.com/forums/show...ons&perpage=20

As for shorter flight times, a higher IR pack will give less flight times because they will produce more heat which is lost energy that "should have" been turned into longer flights.

Your ESR meter is reading correctly. We must assume that a pack label's C rating should be only about 1/2 of its printed rating with the exception of the heavier graphene infused packs such as the Turnigy Graphene, Panther's, select CHL , REVO and a very few few others. The Panther packs will produce an actual 55C though I have found that they will not show much over 33C on the ESR meter as the SW did not know of such a low IR at the time the SW was written.
The ESR meter reads the correct IR though. It just struggles to generate accurate safe constant C values so the research that Joe did is very valuable for researching what packs are best for the application it is to be used on.

Rick
Sep 07, 2018, 10:55 AM
Registered User
Bill Glover's Avatar
Quote:
Originally Posted by rampman
As for shorter flight times, a higher IR pack will give less flight times because they will produce more heat which is lost energy that "should have" been turned into longer flights.
That's true, but with a peak current draw in flight of under 6C I doubt the amount of energy lost to heat would be significant here.

More likely it's the higher voltage drop under load triggering a low voltage warning when the pack actually still has plenty of charge left.
Latest blog entry: Eachine QX65 FPV quad review
Sep 09, 2018, 06:01 PM
Don L.
Thank you, Bill and Rick.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product Esr meter - universal version update Wayne Giles Batteries and Chargers 22 May 23, 2016 05:53 PM