Thank mnr.
Howell batteries (cells)
- Thread starter Resistance
- Start date
As @adriaanh said. BossVape
Sorry. Keep pressing the funny icon by mistake. I agree.
Sorry boys. With shipping two or three cells aren't feasible to courier. I get the Howells for the sake of science
Mantech have reasonably priced high power low resistance resistors, to build up a test jig capable of a 25A, (30A?), draw, as well as 18650 sleds
Do you have access to an infrared thermometer? and an accurate Voltmeter / Multimeter, as that should be all you require to test them.
If I knew where to lay my hands on a few, I'd gladly test them for you, (and NO!, I ain't stripping my UPS for test samples
I can send you some for testing, just got these in (from reputable suppliers) and so far they are doing great. The honest truth is it is very hard to get 25R and 30Q at the moment so our supplier arranged these.
If you will PM me your address I will arrange a set to be sent to you. I would also like to see more!
PM en route
In the meantime ... there's a quick check you can do, (I'd recommend that everyone do this "test" fairly often to keep an eye on their cell aging, and initially to pair cells correctly) ... In the example below, I indicate a 1Ohm resistor ... please ensure that it's a 20 Watt or greater resistor, (preferably an Aluminium one bolted to a heatsink)
P = I * V
= 3.99 * 3.99
= 15.92 Watts
You can do the testing for us @Intuthu Kagesi. You have more nd better experience with these things.
I have just received two Grey 2500mA/hr and two Purple 3000mA/hr cells ... Thanks @Rooigevaar for arranging the test subjects.
Consistency is already order of the day, as out the box measurements show both sets as matched voltages, so we're off to a good start ... the 2500's being 3.562Volts and the 3000's being 3.544 Volts ... and they're in the charger being charged at 250mA, slowly on purpose, as I wish to conform capacities, something a fast charge will skew.
Internal Resistance and discharge tests with temp monitoring to follow.
Would you like destructive tests included? or are we just going for non destructive confirmation of claimed specification(s).
@Rooigevaar you're awesome!
Let the testing begin ...
We have a fully Charged Voltages on the 2500mA/hr cells of 4.194, and 4.190 Volts, and on the 3000mA/hr cells of 4.197 and 4.185 Volts
They'll be plugged into their own iterations of the circuit below for those interested, and in +- 10 hours time we'll have some answers, (they will typically be lower numbers the first time around);
The circuit below uses an adjustable zener diode, which will turn off the load when the cells reach 3 Volts. The cell voltages and time taken to reach 3Volts will be logged, and as they are being discharged through known value resistors, the individual cell capacities can then be calculated, and posted here later.
We have a fully Charged Voltages on the 2500mA/hr cells of 4.194, and 4.190 Volts, and on the 3000mA/hr cells of 4.197 and 4.185 Volts
They'll be plugged into their own iterations of the circuit below for those interested, and in +- 10 hours time we'll have some answers, (they will typically be lower numbers the first time around);
The circuit below uses an adjustable zener diode, which will turn off the load when the cells reach 3 Volts. The cell voltages and time taken to reach 3Volts will be logged, and as they are being discharged through known value resistors, the individual cell capacities can then be calculated, and posted here later.
I just checked the Howell web site, and see that they do in fact publish some spec's ... notably their cut off voltage, which is higher than Samsungs 2.5Volts, however, as most mods shut down at 3Volts ... I'm going to let this test run out as planned.
It does however highlight the possibility that these 3000mA/hr cells may well outperform a 30Q in a mod wrt useable charge as apposed specification, and ... lets wait and see
It does however highlight the possibility that these 3000mA/hr cells may well outperform a 30Q in a mod wrt useable charge as apposed specification, and ... lets wait and see
Round One's data is in, and this is going to have a few eyebrows raised!
The 2500mA hr cells came in at; 2699mA/hr and 2692mA/hr
The 3000mA/hr cells came in at; 3143mA/hr and 3141mA/hr
I'll repeat this test a few times and post an average before moving on to internal resistance measurement and high current discharging, to which the following circuit will be used. This will overcome the challenge of an ever shrinking battery voltage as the cells discharge, maintaining a constant preset discharge current.
The 2500mA hr cells came in at; 2699mA/hr and 2692mA/hr
The 3000mA/hr cells came in at; 3143mA/hr and 3141mA/hr
I'll repeat this test a few times and post an average before moving on to internal resistance measurement and high current discharging, to which the following circuit will be used. This will overcome the challenge of an ever shrinking battery voltage as the cells discharge, maintaining a constant preset discharge current.
I decided to put the cell discharging to good use whilst confirming capacity today, and concluded the CDR / temperature measurement along with internal resistance measurements ... to which we have the following averages;
2500mAh Cells: 18 mOhm
3000mAh Cells: 22 mOhm
With respect to the 2500mAh cells; At 10A continuous these cells juuuuust edged past 2600mAh, and as this is good performance for a 2600mAh-rated cell operating at 10A, it's fair to call them just that, in spite of it being above the 2500mAh markings on the cell itself, and ... it's still inline with the specifications quoted on Howells web site, (see earlier post above).
At 15A continuous the temperature rose to 68°C ... still an acceptable operating temperature for a cell operating within its rated CDR
At 20A continuous the temperature rose to 77°C ... acceptable, albeit high as an operating temperature for a cell operating at its CDR, however it's indicative of being close if not at the cell's CDR!
At 25A continuous the temperature rose to 85°C. This is above an acceptable operating temperature for a cell operating at its CDR, meaning it was being discharged above it's CDR, so I believe it's fair to call these 20A cells, (certainly the two I tested).
Then to the 3000mAh cells; At 10A continuous these cells also just edged past their rating of 3000mAh, and like the aforementioned "2500's", this is good performance for a 3000mAh-rated cell operating at 10A, so it's fair to call this a 3000mA cell, and ... it's inline with the specifications quoted on Howells web site.
At 15A continuous the cell temperature rose to 78°C, high, but an acceptable operating temperature for a cell operating at its CDR, however at current levels above 15Amps, the voltage sag and power loss within the cell became unacceptably large, and the temperature rocketed above 78°C, so I would NOT recommend exceeding 20Amps! .... I must point out that these are not high current / high performance cells, rather they are a high capacity cells, (the internal resistance being the give away), and I would rate them as close as dammit to Samsung 30Q's paper spec. albeit that they beat Samsung on claimed cycle life 1000 vs. 300, (unconfirmed)
As to the mA hour ratings ... give or take a few mA ... they've barely moved, (and I may add that I was concerned, as most new cells GO UP after a few initial cycles).
Please note that whilst all my equipment is in date, (calibrated by an ANAB accredited laboratory ... Instech Calibration), there may well be small discrepancies between Mooch's methodologies and mine, and I'd welcome a follow up test with new boxed 25R and 30Q cells to calibrate Moochs results to mine, and compare them in turn to the Howell cells above.
Thank you again for providing the test cells @Rooigevaar, and;
Thanks for bringing these cells to our attention @Resistance
2500mAh Cells: 18 mOhm
3000mAh Cells: 22 mOhm
With respect to the 2500mAh cells; At 10A continuous these cells juuuuust edged past 2600mAh, and as this is good performance for a 2600mAh-rated cell operating at 10A, it's fair to call them just that, in spite of it being above the 2500mAh markings on the cell itself, and ... it's still inline with the specifications quoted on Howells web site, (see earlier post above).
At 15A continuous the temperature rose to 68°C ... still an acceptable operating temperature for a cell operating within its rated CDR
At 20A continuous the temperature rose to 77°C ... acceptable, albeit high as an operating temperature for a cell operating at its CDR, however it's indicative of being close if not at the cell's CDR!
At 25A continuous the temperature rose to 85°C. This is above an acceptable operating temperature for a cell operating at its CDR, meaning it was being discharged above it's CDR, so I believe it's fair to call these 20A cells, (certainly the two I tested).
Then to the 3000mAh cells; At 10A continuous these cells also just edged past their rating of 3000mAh, and like the aforementioned "2500's", this is good performance for a 3000mAh-rated cell operating at 10A, so it's fair to call this a 3000mA cell, and ... it's inline with the specifications quoted on Howells web site.
At 15A continuous the cell temperature rose to 78°C, high, but an acceptable operating temperature for a cell operating at its CDR, however at current levels above 15Amps, the voltage sag and power loss within the cell became unacceptably large, and the temperature rocketed above 78°C, so I would NOT recommend exceeding 20Amps! .... I must point out that these are not high current / high performance cells, rather they are a high capacity cells, (the internal resistance being the give away), and I would rate them as close as dammit to Samsung 30Q's paper spec. albeit that they beat Samsung on claimed cycle life 1000 vs. 300
, (unconfirmed)As to the mA hour ratings ... give or take a few mA ... they've barely moved, (and I may add that I was concerned, as most new cells GO UP after a few initial cycles).
Please note that whilst all my equipment is in date, (calibrated by an ANAB accredited laboratory ... Instech Calibration), there may well be small discrepancies between Mooch's methodologies and mine, and I'd welcome a follow up test with new boxed 25R and 30Q cells to calibrate Moochs results to mine, and compare them in turn to the Howell cells above.
Thank you again for providing the test cells @Rooigevaar, and;
Thanks for bringing these cells to our attention @Resistance
Well @Intuthu Kagesi your the man!I decided to put the cell discharging to good use whilst confirming capacity today, and concluded the CDR / temperature measurement along with internal resistance measurements ... to which we have the following averages;
2500mAh Cells: 18 mOhm
3000mAh Cells: 22 mOhm
With respect to the 2500mAh cells; At 10A continuous these cells juuuuust edged past 2600mAh, and as this is good performance for a 2600mAh-rated cell operating at 10A, it's fair to call them just that, in spite of it being above the 2500mAh markings on the cell itself, and ... it's still inline with the specifications quoted on Howells web site, (see earlier post above).
At 15A continuous the temperature rose to 68°C ... still an acceptable operating temperature for a cell operating within its rated CDR
At 20A continuous the temperature rose to 77°C ... acceptable, albeit high as an operating temperature for a cell operating at its CDR, however it's indicative of being close if not at the cell's CDR!
At 25A continuous the temperature rose to 85°C. This is above an acceptable operating temperature for a cell operating at its CDR, meaning it was being discharged above it's CDR, so I believe it's fair to call these 20A cells, (certainly the two I tested).
Then to the 3000mAh cells; At 10A continuous these cells also just edged past their rating of 3000mAh, and like the aforementioned "2500's", this is good performance for a 3000mAh-rated cell operating at 10A, so it's fair to call this a 3000mA cell, and ... it's inline with the specifications quoted on Howells web site.
At 15A continuous the cell temperature rose to 78°C, high, but an acceptable operating temperature for a cell operating at its CDR, however at current levels above 15Amps, the voltage sag and power loss within the cell became unacceptably large, and the temperature rocketed above 78°C, so I would NOT recommend exceeding 20Amps! .... I must point out that these are not high current / high performance cells, rather they are a high capacity cells, (the internal resistance being the give away), and I would rate them as close as dammit to Samsung 30Q's paper spec. albeit that they beat Samsung on claimed cycle life 1000 vs. 300
As to the mA hour ratings ... give or take a few mA ... they've barely moved, (and I may add that I was concerned, as most new cells GO UP after a few initial cycles).
Please note that whilst all my equipment is in date, (calibrated by an ANAB accredited laboratory ... Instech Calibration), there may well be small discrepancies between Mooch's methodologies and mine, and I'd welcome a follow up test with new boxed 25R and 30Q cells to calibrate Moochs results to mine, and compare them in turn to the Howell cells above.
Thank you again for providing the test cells @Rooigevaar, and;
Thanks for bringing these cells to our attention @Resistance
Your skills and knowledge have once again proven its worth on the forum. Thanks for taking the time out to test these cells for us.
And @Rooigevaar thanks for backing and sending the product for testing purposes.
I decided to put the cell discharging to good use whilst confirming capacity today, and concluded the CDR / temperature measurement along with internal resistance measurements ... to which we have the following averages;
2500mAh Cells: 18 mOhm
3000mAh Cells: 22 mOhm
With respect to the 2500mAh cells; At 10A continuous these cells juuuuust edged past 2600mAh, and as this is good performance for a 2600mAh-rated cell operating at 10A, it's fair to call them just that, in spite of it being above the 2500mAh markings on the cell itself, and ... it's still inline with the specifications quoted on Howells web site, (see earlier post above).
At 15A continuous the temperature rose to 68°C ... still an acceptable operating temperature for a cell operating within its rated CDR
At 20A continuous the temperature rose to 77°C ... acceptable, albeit high as an operating temperature for a cell operating at its CDR, however it's indicative of being close if not at the cell's CDR!
At 25A continuous the temperature rose to 85°C. This is above an acceptable operating temperature for a cell operating at its CDR, meaning it was being discharged above it's CDR, so I believe it's fair to call these 20A cells, (certainly the two I tested).
Then to the 3000mAh cells; At 10A continuous these cells also just edged past their rating of 3000mAh, and like the aforementioned "2500's", this is good performance for a 3000mAh-rated cell operating at 10A, so it's fair to call this a 3000mA cell, and ... it's inline with the specifications quoted on Howells web site.
At 15A continuous the cell temperature rose to 78°C, high, but an acceptable operating temperature for a cell operating at its CDR, however at current levels above 15Amps, the voltage sag and power loss within the cell became unacceptably large, and the temperature rocketed above 78°C, so I would NOT recommend exceeding 20Amps! .... I must point out that these are not high current / high performance cells, rather they are a high capacity cells, (the internal resistance being the give away), and I would rate them as close as dammit to Samsung 30Q's paper spec. albeit that they beat Samsung on claimed cycle life 1000 vs. 300
As to the mA hour ratings ... give or take a few mA ... they've barely moved, (and I may add that I was concerned, as most new cells GO UP after a few initial cycles).
Please note that whilst all my equipment is in date, (calibrated by an ANAB accredited laboratory ... Instech Calibration), there may well be small discrepancies between Mooch's methodologies and mine, and I'd welcome a follow up test with new boxed 25R and 30Q cells to calibrate Moochs results to mine, and compare them in turn to the Howell cells above.
Thank you again for providing the test cells @Rooigevaar, and;
Thanks for bringing these cells to our attention @Resistance
Thank you for testing these cells!! Greatly appreciated!!
You're most welcome ... I had a lot of fun doing it ... especially the high current discharge tests, literally poeping myself at times as cell temperatures rose, wondering if I'd hit "the point of no return" / thermal runaway
, and then breathing a sigh of relief as cell temperatures came down slowly
You're about to be pleasantly surprised
After the thrashing I gave the Howell 2500 / 2600's in testing ... here they are stacked against "a rival"
... I'll let you guess whether it's the left or right mod whilst you conduct your own testing 
My guess left. Is the 3kmah and right is 2k5mahAfter the thrashing I gave the Howell 2500 / 2600's in testing ... here they are stacked against "a rival"
View attachment 251113
Only one of them has Howells in, and the other, "rival cells"
, to which the "seat of the pants test" is already showing a 10% differential
OK I misread. Sorry I misreadOnly one of them has Howells in, and the other, "rival cells"
No prob. ...
Yes its evident there's a miss.Only one of them has Howells in, and the other, "rival cells"
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