SMC 40C+ C-Max 7.4V Hardcase Lipos
12-20-2008, 11:41 PM
#61
Tech Rookie
Hello Danny,
Thank you for posting the cell test data. It shows that both cells perform very well compared to other offerings in the market today!
That said, we’d like to better inform you of our testing criteria and results, and to point out a few potential issues that may not have been considered with the testing that was done by your manufacturer and the data you’ve provided for your and our cell:
We have indeed tested our 40C cells at the true 40C rate (200 amps for a 5000mAh parallel cell arrangement) and found them to deliver more than 90% capacity when discharged to a 3.0V cutoff. The 40C discharge tests (and prior lower C rate “formatting/break in” cycles) were conducted using freshly manufactured “bare” cells (not cells pulled/removed from an assembled battery pack) charged at 1C to 4.20V each. You can see the graph including the 40C/200 amp discharge test results for a typical 5000mAh parallel cell arrangement below.
And while true that variations in test equipment, procedures and conditions can result in the differences in data obtained by various testers, please also keep in mind the following (which we do not know impacted the results for certain, but could have indeed):
- You’re cell manufacturer appears to have tested one of our cells pulled/removed from an assembled battery pack. As you may be aware, it’s very easy to damage the tabs (ultrasonically welded to the tabs of other cells, usually damaged and causing the mechanical integrity/performance of which to be negatively compromised when pulled apart from the tabs of other cells) and/or “foil pouch” (joined to the foil pouch of the adjoining cell using very thin and relatively strong double-sided tape that is difficult to remove without negatively compromising the integrity/vacuum of the foil pouch) of a cell when pulling it apart from other cells. Either form of damage (or a combination of both) can result in performance losses that do not allow the performance of the removed cell to be accurately tested, measured and determined. We’ve often found cells that are pulled/removed from assembled battery packs not to provide accurate performance and data as a result, which is why we typically only test assembled battery packs from our competitors. Or, if we would like to most accurately test the performance of the individual cell, we order freshly manufactured bare cells from the cell manufacturer.
- The cell you tested from our battery pack is a mass production batch yielded cell that was manufactured a number of months ago and sat at storage charge for a few months. Generally speaking, it is not best to test an aged cell in comparison to a freshly produced cell if you want to obtain the most accurate results.
- Again, our cell is direct from a mass production batch of cells and not a sample pre-production batch. You may be familiar with the phrase “golden sample(s)” in the world of LiPo cells. We had our first experience with this nearly 6 years ago when we tested the first 2100mAh cells with a 15C continuous discharge rate capability. These were sample pre-production batch cells manufactured with more strictly controlled material and production standards and by much more skilled staff than typical mass production batch cells (as is often the case for sample pre-production cells), sent for initial testing and evaluation prior to the cells being put into mass production. However, our QA checks of random samples from the mass production batch of cells (when they arrived some weeks later) showed that the production cells had a maximum 12C continuous discharge rate capability (not the 15C capability of the sample pre-production cells). As a result we only rated the production cells/packs at 12C and constantly test random QA samples from mass production batches in order to ensure quality and accurate rating of the cells/packs we sell due to potential variations in the performance between sample pre-production and mass production cells (as well as the variation between various batches of mass production cells).
And although the cell your manufacturer produced and tested may or may not perform the same as a mass production batch cell, it will be much more relative and accurate to compare the performance of a bare mass production cell to that of another bare mass production cell. That said, we are more than willing to send you a bare, freshly manufactured mass production cell to test if you would also be willing to send us one of yours from the mass production batch in order to better confirm the results published by one another.
The above info aside though, what matters most of course is true on track performance and how any manufacturer’s randomly purchased battery pack performs for an individual in their actual application and under their own controlled test conditions. This is the only time a real comparison can be made between the batteries and published data from different brands. We are more than confident in the performance of our current and future planned releases of 40C+ products, and look forward to seeing the comparisons from the individuals to which the relative performance between brands matters most. We believe their results speak far more to them and everyone else than the results either of us can publish for any cell/pack.
Thank you for posting the cell test data. It shows that both cells perform very well compared to other offerings in the market today!
That said, we’d like to better inform you of our testing criteria and results, and to point out a few potential issues that may not have been considered with the testing that was done by your manufacturer and the data you’ve provided for your and our cell:
We have indeed tested our 40C cells at the true 40C rate (200 amps for a 5000mAh parallel cell arrangement) and found them to deliver more than 90% capacity when discharged to a 3.0V cutoff. The 40C discharge tests (and prior lower C rate “formatting/break in” cycles) were conducted using freshly manufactured “bare” cells (not cells pulled/removed from an assembled battery pack) charged at 1C to 4.20V each. You can see the graph including the 40C/200 amp discharge test results for a typical 5000mAh parallel cell arrangement below.
And while true that variations in test equipment, procedures and conditions can result in the differences in data obtained by various testers, please also keep in mind the following (which we do not know impacted the results for certain, but could have indeed):
- You’re cell manufacturer appears to have tested one of our cells pulled/removed from an assembled battery pack. As you may be aware, it’s very easy to damage the tabs (ultrasonically welded to the tabs of other cells, usually damaged and causing the mechanical integrity/performance of which to be negatively compromised when pulled apart from the tabs of other cells) and/or “foil pouch” (joined to the foil pouch of the adjoining cell using very thin and relatively strong double-sided tape that is difficult to remove without negatively compromising the integrity/vacuum of the foil pouch) of a cell when pulling it apart from other cells. Either form of damage (or a combination of both) can result in performance losses that do not allow the performance of the removed cell to be accurately tested, measured and determined. We’ve often found cells that are pulled/removed from assembled battery packs not to provide accurate performance and data as a result, which is why we typically only test assembled battery packs from our competitors. Or, if we would like to most accurately test the performance of the individual cell, we order freshly manufactured bare cells from the cell manufacturer.
- The cell you tested from our battery pack is a mass production batch yielded cell that was manufactured a number of months ago and sat at storage charge for a few months. Generally speaking, it is not best to test an aged cell in comparison to a freshly produced cell if you want to obtain the most accurate results.
- Again, our cell is direct from a mass production batch of cells and not a sample pre-production batch. You may be familiar with the phrase “golden sample(s)” in the world of LiPo cells. We had our first experience with this nearly 6 years ago when we tested the first 2100mAh cells with a 15C continuous discharge rate capability. These were sample pre-production batch cells manufactured with more strictly controlled material and production standards and by much more skilled staff than typical mass production batch cells (as is often the case for sample pre-production cells), sent for initial testing and evaluation prior to the cells being put into mass production. However, our QA checks of random samples from the mass production batch of cells (when they arrived some weeks later) showed that the production cells had a maximum 12C continuous discharge rate capability (not the 15C capability of the sample pre-production cells). As a result we only rated the production cells/packs at 12C and constantly test random QA samples from mass production batches in order to ensure quality and accurate rating of the cells/packs we sell due to potential variations in the performance between sample pre-production and mass production cells (as well as the variation between various batches of mass production cells).
And although the cell your manufacturer produced and tested may or may not perform the same as a mass production batch cell, it will be much more relative and accurate to compare the performance of a bare mass production cell to that of another bare mass production cell. That said, we are more than willing to send you a bare, freshly manufactured mass production cell to test if you would also be willing to send us one of yours from the mass production batch in order to better confirm the results published by one another.
The above info aside though, what matters most of course is true on track performance and how any manufacturer’s randomly purchased battery pack performs for an individual in their actual application and under their own controlled test conditions. This is the only time a real comparison can be made between the batteries and published data from different brands. We are more than confident in the performance of our current and future planned releases of 40C+ products, and look forward to seeing the comparisons from the individuals to which the relative performance between brands matters most. We believe their results speak far more to them and everyone else than the results either of us can publish for any cell/pack.
12-21-2008, 05:45 AM
#63
Tech Fanatic
Hello Danny,
Thank you for posting the cell test data. It shows that both cells perform very well compared to other offerings in the market today!
That said, we’d like to better inform you of our testing criteria and results, and to point out a few potential issues that may not have been considered with the testing that was done by your manufacturer and the data you’ve provided for your and our cell:
We have indeed tested our 40C cells at the true 40C rate (200 amps for a 5000mAh parallel cell arrangement) and found them to deliver more than 90% capacity when discharged to a 3.0V cutoff. The 40C discharge tests (and prior lower C rate “formatting/break in” cycles) were conducted using freshly manufactured “bare” cells (not cells pulled/removed from an assembled battery pack) charged at 1C to 4.20V each. You can see the graph including the 40C/200 amp discharge test results for a typical 5000mAh parallel cell arrangement below.
And while true that variations in test equipment, procedures and conditions can result in the differences in data obtained by various testers, please also keep in mind the following (which we do not know impacted the results for certain, but could have indeed):
- You’re cell manufacturer appears to have tested one of our cells pulled/removed from an assembled battery pack. As you may be aware, it’s very easy to damage the tabs (ultrasonically welded to the tabs of other cells, usually damaged and causing the mechanical integrity/performance of which to be negatively compromised when pulled apart from the tabs of other cells) and/or “foil pouch” (joined to the foil pouch of the adjoining cell using very thin and relatively strong double-sided tape that is difficult to remove without negatively compromising the integrity/vacuum of the foil pouch) of a cell when pulling it apart from other cells. Either form of damage (or a combination of both) can result in performance losses that do not allow the performance of the removed cell to be accurately tested, measured and determined. We’ve often found cells that are pulled/removed from assembled battery packs not to provide accurate performance and data as a result, which is why we typically only test assembled battery packs from our competitors. Or, if we would like to most accurately test the performance of the individual cell, we order freshly manufactured bare cells from the cell manufacturer.
- The cell you tested from our battery pack is a mass production batch yielded cell that was manufactured a number of months ago and sat at storage charge for a few months. Generally speaking, it is not best to test an aged cell in comparison to a freshly produced cell if you want to obtain the most accurate results.
- Again, our cell is direct from a mass production batch of cells and not a sample pre-production batch. You may be familiar with the phrase “golden sample(s)” in the world of LiPo cells. We had our first experience with this nearly 6 years ago when we tested the first 2100mAh cells with a 15C continuous discharge rate capability. These were sample pre-production batch cells manufactured with more strictly controlled material and production standards and by much more skilled staff than typical mass production batch cells (as is often the case for sample pre-production cells), sent for initial testing and evaluation prior to the cells being put into mass production. However, our QA checks of random samples from the mass production batch of cells (when they arrived some weeks later) showed that the production cells had a maximum 12C continuous discharge rate capability (not the 15C capability of the sample pre-production cells). As a result we only rated the production cells/packs at 12C and constantly test random QA samples from mass production batches in order to ensure quality and accurate rating of the cells/packs we sell due to potential variations in the performance between sample pre-production and mass production cells (as well as the variation between various batches of mass production cells).
And although the cell your manufacturer produced and tested may or may not perform the same as a mass production batch cell, it will be much more relative and accurate to compare the performance of a bare mass production cell to that of another bare mass production cell. That said, we are more than willing to send you a bare, freshly manufactured mass production cell to test if you would also be willing to send us one of yours from the mass production batch in order to better confirm the results published by one another.
The above info aside though, what matters most of course is true on track performance and how any manufacturer’s randomly purchased battery pack performs for an individual in their actual application and under their own controlled test conditions. This is the only time a real comparison can be made between the batteries and published data from different brands. We are more than confident in the performance of our current and future planned releases of 40C+ products, and look forward to seeing the comparisons from the individuals to which the relative performance between brands matters most. We believe their results speak far more to them and everyone else than the results either of us can publish for any cell/pack.
Thank you for posting the cell test data. It shows that both cells perform very well compared to other offerings in the market today!
That said, we’d like to better inform you of our testing criteria and results, and to point out a few potential issues that may not have been considered with the testing that was done by your manufacturer and the data you’ve provided for your and our cell:
We have indeed tested our 40C cells at the true 40C rate (200 amps for a 5000mAh parallel cell arrangement) and found them to deliver more than 90% capacity when discharged to a 3.0V cutoff. The 40C discharge tests (and prior lower C rate “formatting/break in” cycles) were conducted using freshly manufactured “bare” cells (not cells pulled/removed from an assembled battery pack) charged at 1C to 4.20V each. You can see the graph including the 40C/200 amp discharge test results for a typical 5000mAh parallel cell arrangement below.
And while true that variations in test equipment, procedures and conditions can result in the differences in data obtained by various testers, please also keep in mind the following (which we do not know impacted the results for certain, but could have indeed):
- You’re cell manufacturer appears to have tested one of our cells pulled/removed from an assembled battery pack. As you may be aware, it’s very easy to damage the tabs (ultrasonically welded to the tabs of other cells, usually damaged and causing the mechanical integrity/performance of which to be negatively compromised when pulled apart from the tabs of other cells) and/or “foil pouch” (joined to the foil pouch of the adjoining cell using very thin and relatively strong double-sided tape that is difficult to remove without negatively compromising the integrity/vacuum of the foil pouch) of a cell when pulling it apart from other cells. Either form of damage (or a combination of both) can result in performance losses that do not allow the performance of the removed cell to be accurately tested, measured and determined. We’ve often found cells that are pulled/removed from assembled battery packs not to provide accurate performance and data as a result, which is why we typically only test assembled battery packs from our competitors. Or, if we would like to most accurately test the performance of the individual cell, we order freshly manufactured bare cells from the cell manufacturer.
- The cell you tested from our battery pack is a mass production batch yielded cell that was manufactured a number of months ago and sat at storage charge for a few months. Generally speaking, it is not best to test an aged cell in comparison to a freshly produced cell if you want to obtain the most accurate results.
- Again, our cell is direct from a mass production batch of cells and not a sample pre-production batch. You may be familiar with the phrase “golden sample(s)” in the world of LiPo cells. We had our first experience with this nearly 6 years ago when we tested the first 2100mAh cells with a 15C continuous discharge rate capability. These were sample pre-production batch cells manufactured with more strictly controlled material and production standards and by much more skilled staff than typical mass production batch cells (as is often the case for sample pre-production cells), sent for initial testing and evaluation prior to the cells being put into mass production. However, our QA checks of random samples from the mass production batch of cells (when they arrived some weeks later) showed that the production cells had a maximum 12C continuous discharge rate capability (not the 15C capability of the sample pre-production cells). As a result we only rated the production cells/packs at 12C and constantly test random QA samples from mass production batches in order to ensure quality and accurate rating of the cells/packs we sell due to potential variations in the performance between sample pre-production and mass production cells (as well as the variation between various batches of mass production cells).
And although the cell your manufacturer produced and tested may or may not perform the same as a mass production batch cell, it will be much more relative and accurate to compare the performance of a bare mass production cell to that of another bare mass production cell. That said, we are more than willing to send you a bare, freshly manufactured mass production cell to test if you would also be willing to send us one of yours from the mass production batch in order to better confirm the results published by one another.
The above info aside though, what matters most of course is true on track performance and how any manufacturer’s randomly purchased battery pack performs for an individual in their actual application and under their own controlled test conditions. This is the only time a real comparison can be made between the batteries and published data from different brands. We are more than confident in the performance of our current and future planned releases of 40C+ products, and look forward to seeing the comparisons from the individuals to which the relative performance between brands matters most. We believe their results speak far more to them and everyone else than the results either of us can publish for any cell/pack.
12-21-2008, 06:08 AM
#64
The fued between TP and SMC is certainly getting interesting. Its turning into Coke v Pepsi and the like. Will be interesting to see which wins out the place it matters most, the track! My guess is both have more then enough juice to leave it up to the drivers capabilities. At least for 99.999% of us. Rheinhard and Hara might be able to notice a difference 
12-21-2008, 06:59 AM
#65
Tech Fanatic
The fued between TP and SMC is certainly getting interesting. Its turning into Coke v Pepsi and the like. Will be interesting to see which wins out the place it matters most, the track! My guess is both have more then enough juice to leave it up to the drivers capabilities. At least for 99.999% of us. Rheinhard and Hara might be able to notice a difference
Performance for both packs will be really good. It may come down to cycle life in the end.Competition is healthy for the industry. We can't wait to release some new things to the flight market very soon. Things definitely will get interesting next year.
12-21-2008, 08:33 AM
#66
Hi Jason,
Feel free to test and take apart our production packs when they are available. As far as samples versus production it has been our experience that our supplier can do as good if not better in production.
It has never been my way to show/compare our competitors data publicly as SMC is all about selling the best possible product to it's customers and we feel trying to get publicity this way is not beneficial. I made an exception this time due to your post on your thread.
I was very surprised when you decided to publicly post our numbers and impleying something was wrong with them and off course the numbers looked lower on your end. I explained myself and you reccomended I change my label. What upset me the most is if you really wanted to know all of this you could of emailed or PM'ed me. Your colleague Jim PMed me asking for info. I responded via email and I never got a response. I then PMed him to tell him I sent an email and he never replied. Not to long after that you posted challenging the numbers on our packs. I find it flattering that you used our 28C ten month old pack to compare to your new 40C pack. That must mean our pack is pretty good as you didn't compare anyone elses pack.
Now that we have your packs/cells you don't seem to like the fact that we post the info we got on them. We got 2 of your packs. The numbers on both of them are lower than the numbers you posted on your thread. So I can ask myself the same question as you are. Were you testing a sample pack or did you test the best pack you could fine ? Since you were getting lower numbers on our 28C packs and higher on your packs in your testing enviroment I was expecting your packs to be even higher in our testing enviroment which wasn't the case.
I'm confident that the info our supplier provided us is fair and accurate. You can test our packs when they come out and challenge our info if you feel like it. We can have an independent source purchase both our packs and send them to an independent lab for C rate testing and we can split the costs ? That way it removes all doubts of super samples if the cells were fresh or not.
As far as track performance goes there are many packs that can get the job done as RC cars don't pull enough amps and car setup and driving are way more important than a pack with a bit more or less performance. This is why all our testing is done in 3D Helicopters as we feel this is the ultimate test for a pack. Results have been nothing but spectacular in Helis on our 2200/25C packs so were very excited about our 40C+ packs being available in that market as the power will be even better.
Feel free to test and take apart our production packs when they are available. As far as samples versus production it has been our experience that our supplier can do as good if not better in production.
It has never been my way to show/compare our competitors data publicly as SMC is all about selling the best possible product to it's customers and we feel trying to get publicity this way is not beneficial. I made an exception this time due to your post on your thread.
I was very surprised when you decided to publicly post our numbers and impleying something was wrong with them and off course the numbers looked lower on your end. I explained myself and you reccomended I change my label. What upset me the most is if you really wanted to know all of this you could of emailed or PM'ed me. Your colleague Jim PMed me asking for info. I responded via email and I never got a response. I then PMed him to tell him I sent an email and he never replied. Not to long after that you posted challenging the numbers on our packs. I find it flattering that you used our 28C ten month old pack to compare to your new 40C pack. That must mean our pack is pretty good as you didn't compare anyone elses pack.
Now that we have your packs/cells you don't seem to like the fact that we post the info we got on them. We got 2 of your packs. The numbers on both of them are lower than the numbers you posted on your thread. So I can ask myself the same question as you are. Were you testing a sample pack or did you test the best pack you could fine ? Since you were getting lower numbers on our 28C packs and higher on your packs in your testing enviroment I was expecting your packs to be even higher in our testing enviroment which wasn't the case.
I'm confident that the info our supplier provided us is fair and accurate. You can test our packs when they come out and challenge our info if you feel like it. We can have an independent source purchase both our packs and send them to an independent lab for C rate testing and we can split the costs ? That way it removes all doubts of super samples if the cells were fresh or not.
As far as track performance goes there are many packs that can get the job done as RC cars don't pull enough amps and car setup and driving are way more important than a pack with a bit more or less performance. This is why all our testing is done in 3D Helicopters as we feel this is the ultimate test for a pack. Results have been nothing but spectacular in Helis on our 2200/25C packs so were very excited about our 40C+ packs being available in that market as the power will be even better.
12-21-2008, 09:03 AM
#67
Danny,
I was following this topic because i to have decided to run lipos next year. now i wondered if this comment was related to stock motor, 9.5t and up, cars or ANY cars (including modified low turn brushless motors)
my clubs is i think the only club in the netherlands that still runs modified with 6cells and since last year also allowed lipo for modified. we mostly run 3.5 and 4.0 turn motors so i think we ask quite a lot from our batteries.
so now i am looking at what is available but also at how not to kill the lipos to quick. the main thing i read on was to much discharge is not good for lipos so I do think these high C packs are good for modified right? cause with the power they ask from the cells you don't have to be reinhard to notice the difference.
Tom
I was following this topic because i to have decided to run lipos next year. now i wondered if this comment was related to stock motor, 9.5t and up, cars or ANY cars (including modified low turn brushless motors)
my clubs is i think the only club in the netherlands that still runs modified with 6cells and since last year also allowed lipo for modified. we mostly run 3.5 and 4.0 turn motors so i think we ask quite a lot from our batteries.
so now i am looking at what is available but also at how not to kill the lipos to quick. the main thing i read on was to much discharge is not good for lipos so I do think these high C packs are good for modified right? cause with the power they ask from the cells you don't have to be reinhard to notice the difference.
Tom
12-21-2008, 09:10 AM
#68
Actually higher C rate packs will perform better with faster motors as the amp draw will be increased. They should also have better cycle life as they can handle the higher amp loads better. If your use to running 3.5/4.0 with sub-c cells you will be able to go as fast with 5.5 and a 40C pack. The lower IR and effiencey of the Lipo allows you to use a milder motor.
We will release an EFRA pack as the EFRA rules require a thinner case so our 5000 will not be legal.
We will release an EFRA pack as the EFRA rules require a thinner case so our 5000 will not be legal.
12-21-2008, 09:28 AM
#69
Tech Rookie
Hello Danny,
Thank you for posting the cell test data. It shows that both cells perform very well compared to other offerings in the market today!
That said, we’d like to better inform you of our testing criteria and results, and to point out a few potential issues that may not have been considered with the testing that was done by your manufacturer and the data you’ve provided for your and our cell:
We have indeed tested our 40C cells at the true 40C rate (200 amps for a 5000mAh parallel cell arrangement) and found them to deliver more than 90% capacity when discharged to a 3.0V cutoff. The 40C discharge tests (and prior lower C rate “formatting/break in” cycles) were conducted using freshly manufactured “bare” cells (not cells pulled/removed from an assembled battery pack) charged at 1C to 4.20V each. You can see the graph including the 40C/200 amp discharge test results for a typical 5000mAh parallel cell arrangement below.
And while true that variations in test equipment, procedures and conditions can result in the differences in data obtained by various testers, please also keep in mind the following (which we do not know impacted the results for certain, but could have indeed):
- You’re cell manufacturer appears to have tested one of our cells pulled/removed from an assembled battery pack. As you may be aware, it’s very easy to damage the tabs (ultrasonically welded to the tabs of other cells, usually damaged and causing the mechanical integrity/performance of which to be negatively compromised when pulled apart from the tabs of other cells) and/or “foil pouch” (joined to the foil pouch of the adjoining cell using very thin and relatively strong double-sided tape that is difficult to remove without negatively compromising the integrity/vacuum of the foil pouch) of a cell when pulling it apart from other cells. Either form of damage (or a combination of both) can result in performance losses that do not allow the performance of the removed cell to be accurately tested, measured and determined. We’ve often found cells that are pulled/removed from assembled battery packs not to provide accurate performance and data as a result, which is why we typically only test assembled battery packs from our competitors. Or, if we would like to most accurately test the performance of the individual cell, we order freshly manufactured bare cells from the cell manufacturer.
- The cell you tested from our battery pack is a mass production batch yielded cell that was manufactured a number of months ago and sat at storage charge for a few months. Generally speaking, it is not best to test an aged cell in comparison to a freshly produced cell if you want to obtain the most accurate results.
- Again, our cell is direct from a mass production batch of cells and not a sample pre-production batch. You may be familiar with the phrase “golden sample(s)” in the world of LiPo cells. We had our first experience with this nearly 6 years ago when we tested the first 2100mAh cells with a 15C continuous discharge rate capability. These were sample pre-production batch cells manufactured with more strictly controlled material and production standards and by much more skilled staff than typical mass production batch cells (as is often the case for sample pre-production cells), sent for initial testing and evaluation prior to the cells being put into mass production. However, our QA checks of random samples from the mass production batch of cells (when they arrived some weeks later) showed that the production cells had a maximum 12C continuous discharge rate capability (not the 15C capability of the sample pre-production cells). As a result we only rated the production cells/packs at 12C and constantly test random QA samples from mass production batches in order to ensure quality and accurate rating of the cells/packs we sell due to potential variations in the performance between sample pre-production and mass production cells (as well as the variation between various batches of mass production cells).
And although the cell your manufacturer produced and tested may or may not perform the same as a mass production batch cell, it will be much more relative and accurate to compare the performance of a bare mass production cell to that of another bare mass production cell. That said, we are more than willing to send you a bare, freshly manufactured mass production cell to test if you would also be willing to send us one of yours from the mass production batch in order to better confirm the results published by one another.
The above info aside though, what matters most of course is true on track performance and how any manufacturer’s randomly purchased battery pack performs for an individual in their actual application and under their own controlled test conditions. This is the only time a real comparison can be made between the batteries and published data from different brands. We are more than confident in the performance of our current and future planned releases of 40C+ products, and look forward to seeing the comparisons from the individuals to which the relative performance between brands matters most. We believe their results speak far more to them and everyone else than the results either of us can publish for any cell/pack.
Thank you for posting the cell test data. It shows that both cells perform very well compared to other offerings in the market today!
That said, we’d like to better inform you of our testing criteria and results, and to point out a few potential issues that may not have been considered with the testing that was done by your manufacturer and the data you’ve provided for your and our cell:
We have indeed tested our 40C cells at the true 40C rate (200 amps for a 5000mAh parallel cell arrangement) and found them to deliver more than 90% capacity when discharged to a 3.0V cutoff. The 40C discharge tests (and prior lower C rate “formatting/break in” cycles) were conducted using freshly manufactured “bare” cells (not cells pulled/removed from an assembled battery pack) charged at 1C to 4.20V each. You can see the graph including the 40C/200 amp discharge test results for a typical 5000mAh parallel cell arrangement below.
And while true that variations in test equipment, procedures and conditions can result in the differences in data obtained by various testers, please also keep in mind the following (which we do not know impacted the results for certain, but could have indeed):
- You’re cell manufacturer appears to have tested one of our cells pulled/removed from an assembled battery pack. As you may be aware, it’s very easy to damage the tabs (ultrasonically welded to the tabs of other cells, usually damaged and causing the mechanical integrity/performance of which to be negatively compromised when pulled apart from the tabs of other cells) and/or “foil pouch” (joined to the foil pouch of the adjoining cell using very thin and relatively strong double-sided tape that is difficult to remove without negatively compromising the integrity/vacuum of the foil pouch) of a cell when pulling it apart from other cells. Either form of damage (or a combination of both) can result in performance losses that do not allow the performance of the removed cell to be accurately tested, measured and determined. We’ve often found cells that are pulled/removed from assembled battery packs not to provide accurate performance and data as a result, which is why we typically only test assembled battery packs from our competitors. Or, if we would like to most accurately test the performance of the individual cell, we order freshly manufactured bare cells from the cell manufacturer.
- The cell you tested from our battery pack is a mass production batch yielded cell that was manufactured a number of months ago and sat at storage charge for a few months. Generally speaking, it is not best to test an aged cell in comparison to a freshly produced cell if you want to obtain the most accurate results.
- Again, our cell is direct from a mass production batch of cells and not a sample pre-production batch. You may be familiar with the phrase “golden sample(s)” in the world of LiPo cells. We had our first experience with this nearly 6 years ago when we tested the first 2100mAh cells with a 15C continuous discharge rate capability. These were sample pre-production batch cells manufactured with more strictly controlled material and production standards and by much more skilled staff than typical mass production batch cells (as is often the case for sample pre-production cells), sent for initial testing and evaluation prior to the cells being put into mass production. However, our QA checks of random samples from the mass production batch of cells (when they arrived some weeks later) showed that the production cells had a maximum 12C continuous discharge rate capability (not the 15C capability of the sample pre-production cells). As a result we only rated the production cells/packs at 12C and constantly test random QA samples from mass production batches in order to ensure quality and accurate rating of the cells/packs we sell due to potential variations in the performance between sample pre-production and mass production cells (as well as the variation between various batches of mass production cells).
And although the cell your manufacturer produced and tested may or may not perform the same as a mass production batch cell, it will be much more relative and accurate to compare the performance of a bare mass production cell to that of another bare mass production cell. That said, we are more than willing to send you a bare, freshly manufactured mass production cell to test if you would also be willing to send us one of yours from the mass production batch in order to better confirm the results published by one another.
The above info aside though, what matters most of course is true on track performance and how any manufacturer’s randomly purchased battery pack performs for an individual in their actual application and under their own controlled test conditions. This is the only time a real comparison can be made between the batteries and published data from different brands. We are more than confident in the performance of our current and future planned releases of 40C+ products, and look forward to seeing the comparisons from the individuals to which the relative performance between brands matters most. We believe their results speak far more to them and everyone else than the results either of us can publish for any cell/pack.
As a Lipo manufacturer, I would like to remind you to check carefully before you post the data (graph) to the public. Many of us may not acknowledge the natural performance platform of a ture 40C discharge rate Lipo,however the people who actually make the Lipo may figure out the "mistakes" in your graph.
I appreciate that you are trying to be professional on how to test a Lipo pack and find out the fair testing result to show to all the RC racers and players. So I can't help myself to not pointing out some mistakes that show in your graph. I can never understand why don't you test your pack at 2S2P configuration if you do own the equipment to discharge the pack at 200A discharge current?
I have been in the Lipo industry for over 10 years, so I know which Chinese Lipo manufacturer supply TP the bare cells. I do have access to obtain the bare cells from your supplier and conduct the test. You pack shows good performance,however by comparing my test result to your posted graph, I found some "doubts" about your graph.
Doubt #1: You never provide us the actual discharging time of your 1S2P pack, and the time associate with the drop of voltage. It takes only 4 to 5 seconds to discahrge the pack in 200A to have the voltage dropped from 4.2V to 3.5V. But it takes much longer time to have the voltage dropped to 3.5V according to your graph which I find impossible for a cell or a pack to hold its voltage above 3.5V at such a long time under 200A discharging current.
Doubt#2:According to my test, around 300mAh was able to discharge from a 1S2P pack when the voltage dropped to 3.5V (120mAh for a bare cell). However, according to your curve, the dischage out capacity was over 700mAh already when the voltage dropped to 3.5V. It is really not logical according to the performance platform of a 40C pack.
Doubt#3: The discharging performance platform for a ture 40C pack with the effective discharging voltage is from 3.5V to 3.25V. Not much capacity can be discharged above 3.5V and also below 3.25V. According to your graph, your effective discharging platform is from 3.8V to 3.3V. If it is the turth, I will assume that your pack can be discharged out over 95% of its capacity when under 200A discharging current!? You either find the top of the world Lipo supplier to produce such kind of "super" cell for you or your supplier is making you a handmake graph.
According to my test result, TP did come up with a good 40C Lipo pack. But when it comes to provide the graph with the ture data to show to the consumers, all the data must be faithful. Please change the "mAh" to "Ah" in your graph. As a lipo manufacturer, I just can't stand to see a perfromance graph of a Lipo pack being conducted in such an unreasonable and unprofessional way.
12-21-2008, 09:31 AM
#70
danny,
that looks good then. i am not to bothered about efra regulations as we don't follow them. otherwise we would be killing off sub-C's now with brushless 5cell packs which we didn't think would be a good idea to drain the packs so hard with brushless motors.
So your new 5000's should be a nice step forward.
that looks good then. i am not to bothered about efra regulations as we don't follow them. otherwise we would be killing off sub-C's now with brushless 5cell packs which we didn't think would be a good idea to drain the packs so hard with brushless motors.
So your new 5000's should be a nice step forward.
12-21-2008, 09:40 AM
#71
danny,
that looks good then. i am not to bothered about efra regulations as we don't follow them. otherwise we would be killing off sub-C's now with brushless 5cell packs which we didn't think would be a good idea to drain the packs so hard with brushless motors.
So your new 5000's should be a nice step forward.
that looks good then. i am not to bothered about efra regulations as we don't follow them. otherwise we would be killing off sub-C's now with brushless 5cell packs which we didn't think would be a good idea to drain the packs so hard with brushless motors.
So your new 5000's should be a nice step forward.
12-21-2008, 11:25 AM
#72
It'll be pretty easy to test all these 40C+ packs in a 1/8th scale electric conversion to see how well they perform under racing conditions. We can put a pretty good beating on the cells in our cars that a 1/10th scale car can't.....LOL
As for helicopters I'm sure they'd good for a baseline but in a car the conditions are so much different. Plus you have a lap counter and telemetry that can monitor the run from start to dump
As for helicopters I'm sure they'd good for a baseline but in a car the conditions are so much different. Plus you have a lap counter and telemetry that can monitor the run from start to dump
12-21-2008, 11:42 AM
#73
Actually onroad sedan mod will put more load on a Lipo than 1/8th scale will.
3D Heli flying uses a Lipo at it's maximum potential as they use full throttle for long periods of time and the power setup used pulls allot of amps as they only fly for 3 minutes or so. They also have access to data loggers to see what is going on. Our 2200/25C packs in a 450 Heli has been known to produce 200 extra RPMs of head speed compared to packs from all our competitors.
3D Heli flying uses a Lipo at it's maximum potential as they use full throttle for long periods of time and the power setup used pulls allot of amps as they only fly for 3 minutes or so. They also have access to data loggers to see what is going on. Our 2200/25C packs in a 450 Heli has been known to produce 200 extra RPMs of head speed compared to packs from all our competitors.
12-21-2008, 11:49 AM
#74
Would love to see some drag racers put those 40C from SMC and Thunder Power through some 170A+ (Most of my runs was over 170A and one other drag racer has seen over 180A) runs and see how they hold up to that. I hope to see some price wars as well to keep this hobby more affordable for everyone to enjoy.
12-21-2008, 02:38 PM
#75
Actually onroad sedan mod will put more load on a Lipo than 1/8th scale will.
3D Heli flying uses a Lipo at it's maximum potential as they use full throttle for long periods of time and the power setup used pulls allot of amps as they only fly for 3 minutes or so. They also have access to data loggers to see what is going on. Our 2200/25C packs in a 450 Heli has been known to produce 200 extra RPMs of head speed compared to packs from all our competitors.
3D Heli flying uses a Lipo at it's maximum potential as they use full throttle for long periods of time and the power setup used pulls allot of amps as they only fly for 3 minutes or so. They also have access to data loggers to see what is going on. Our 2200/25C packs in a 450 Heli has been known to produce 200 extra RPMs of head speed compared to packs from all our competitors.