at 3:43 As long as you use 4 wire measurements ( kelvin) the heat loss by the wieres does not impact anything.. The total heat remain the same. It is just split into wire heating and mosfet to heatsink heating of the load... the total dissipated Watt remain the same... ( you can have 100W to the mosfet or 95W to the mosfet and 5% in the cables.. it remain 100W. Let say your cables are infinitly big supraconductors with a true zero ohms each, this will just make your mosfet to take 100% of the dissipated power and no power to the conductors.. BUT it does not matter because the voltage loss is not counted because the sensing wires are at the battery terminal so the voltage reading is the right one and is already compensated. whatever the amp number you have .. if you have 100 foot long cables or 3 foot long cable the amp remain the same. your Ah will not change. As long as you measure the Am properly ( Amp * time in hours) if you connect a 11 amp rated power supply and make a 10.0000A discharge with this tester and make a discharge during 1h00 exactly you should measure 10.0000Ah that's it... no matter the voltage is! Wh depend on voltage and Ah is only related to Amp and time.. not volt and not Wh
Some things to remember: The manufacturer test report is done when the cell is new, after this for the first 1-2 years there is a settling period during which the cell will produce the stated (280 AH) capacity. So it is crucial that it is developed above capacity so this process can happen. If you want to see it match very the listed capacity the tests need to be done on fresh cells, however, this should not be taken as the real world capacity, that should always be the intended spec of 280AH. Generally grade A will have about 2-3% above rated spec in real world use so expect about 285-290 AH (at 3.2v) in real world use.
Are the labels you generate in line with the manufactures test procedures? for example - off the top of my head. Cell temp 25*C +/- 2*C Charge 3.65 @ 0.05C / 14Amp cut off. wait 1 hour Discharge cut off 2.5V @ 0.2C / 56Amps. You could add a shunt and do the test at 40 amps to compare with the Off Grid Garage. I think you have the equipment to test a single cell at 0.2C don't you? whenever I'm testing cells I always add a shunt and log the data with that as a second point of reference. For high current test's , because I don't have a single cell high power tester, I wire in 4s and log the BMS data so I have 3 points of reference . Generally I find the ZKE-40 accurate to around 1.2% when referenced with a PZEM017 or a Victron smart shunt... they are both very accurate.
The labels we generate are from the manufacturers OWN test report, we do not make up these numbers. All grade A manufacturers provide a test report that lists data, we take this data and provide it for buyers so they can assemble there pack. NOTE: the Honey Moon period goes away, even the above cell in about 1 year's Time will test about 285-290. The manufacture test these at RTP but has them clamped in a compression jig. In our own experience the ZKE is about 1% off there tests, but is close enough IF you don't exceed 30 AMP and you use proper lugs instead of those alligator clamps (which waste a lot of energy as heat).
Want me to make you some GX20-3's with 8AWG or 7AWG? I already used up all my GX16-3's (pretty sure the A40 stepped it up to GX20) making custom leads for my Headways and for my "ZKE Battery Rack" along with a few other random ways I wanted to terminate leads for testing the strange stuff I've been buying lately
at 3:43 As long as you use 4 wire measurements ( kelvin) the heat loss by the wieres does not impact anything.. The total heat remain the same. It is just split into wire heating and mosfet to heatsink heating of the load... the total dissipated Watt remain the same... ( you can have 100W to the mosfet or 95W to the mosfet and 5% in the cables.. it remain 100W. Let say your cables are infinitly big supraconductors with a true zero ohms each, this will just make your mosfet to take 100% of the dissipated power and no power to the conductors.. BUT it does not matter because the voltage loss is not counted because the sensing wires are at the battery terminal so the voltage reading is the right one and is already compensated. whatever the amp number you have .. if you have 100 foot long cables or 3 foot long cable the amp remain the same. your Ah will not change. As long as you measure the Am properly ( Amp * time in hours) if you connect a 11 amp rated power supply and make a 10.0000A discharge with this tester and make a discharge during 1h00 exactly you should measure 10.0000Ah that's it... no matter the voltage is! Wh depend on voltage and Ah is only related to Amp and time.. not volt and not Wh
Wow these are incredible! When will the V4 kit be available?
Soon! Very Soon!😁
Some things to remember: The manufacturer test report is done when the cell is new, after this for the first 1-2 years there is a settling period during which the cell will produce the stated (280 AH) capacity. So it is crucial that it is developed above capacity so this process can happen. If you want to see it match very the listed capacity the tests need to be done on fresh cells, however, this should not be taken as the real world capacity, that should always be the intended spec of 280AH. Generally grade A will have about 2-3% above rated spec in real world use so expect about 285-290 AH (at 3.2v) in real world use.
Are the labels you generate in line with the manufactures test procedures? for example - off the top of my head.
Cell temp 25*C +/- 2*C
Charge 3.65 @ 0.05C / 14Amp cut off.
wait 1 hour
Discharge cut off 2.5V @ 0.2C / 56Amps.
You could add a shunt and do the test at 40 amps to compare with the Off Grid Garage. I think you have the equipment to test a single cell at 0.2C don't you? whenever I'm testing cells I always add a shunt and log the data with that as a second point of reference. For high current test's , because I don't have a single cell high power tester, I wire in 4s and log the BMS data so I have 3 points of reference .
Generally I find the ZKE-40 accurate to around 1.2% when referenced with a PZEM017 or a Victron smart shunt... they are both very accurate.
The labels we generate are from the manufacturers OWN test report, we do not make up these numbers. All grade A manufacturers provide a test report that lists data, we take this data and provide it for buyers so they can assemble there pack.
NOTE: the Honey Moon period goes away, even the above cell in about 1 year's Time will test about 285-290.
The manufacture test these at RTP but has them clamped in a compression jig. In our own experience the ZKE is about 1% off there tests, but is close enough IF you don't exceed 30 AMP and you use proper lugs instead of those alligator clamps (which waste a lot of energy as heat).
@@sfkenergy I see, very good.
I agree with what you have said. Thanks for the reply😀
Full ZKE report & test data available here: drive.google.com/drive/u/1/folders/1hsk0XKOE_enGtW1YJ3ro1BqLO_X5LmvH
Want me to make you some GX20-3's with 8AWG or 7AWG? I already used up all my GX16-3's (pretty sure the A40 stepped it up to GX20) making custom leads for my Headways and for my "ZKE Battery Rack" along with a few other random ways I wanted to terminate leads for testing the strange stuff I've been buying lately