MNKE 26650 5000mah cycle test

saved for 4.2v-3.2v capacity tests

#1


after 100 cycles



after 160 cycles



#1


after 100 cycles



after 160 cycles

first cycle, im changing 1-1 setting, had problems starting the charge and lost almost 200mah and will post 2nd cycle as the reference then every 50 cycles



battery temperature at end of each step below
1-1 is 80f, 1-2 at 3.75a c/o is 80f, 1-3 is 75f, 1-4 is 92f, 1-5 is 100f, 1-6 is 94f, 1-7 is 87f, 1-8 is 84f and cycle 2 charge starts

discharge #1 4963mah



2nd cycle



discharge 4965mah, charge 4901mah



10th cycle



the mah increased , discharge 4969mah, charge 4907mah



cycle #50 discharge 4920mah

different charge settings

after charging and sitting for 8hrs volt dropped to 4.14v



might need to lower c/o?

topped off with 0.5a charge 0.25c/o



volt was 4.184 so i topped it off 0.10c/o wich gave me 4.191v



i was thinking of running this cell at 4.15v so i should get that with an 0.30a-c/o

i set 2amp charge to switch at 3.55v but need to raise it to 3.6v

not much information on this battery, going to try same settings as 40T but with different magnets and copper slug tape.





1.75"x3" tape







Plasti dip



battery was 3.878v , heres the charge, might change c/o to 0.25a



tracking where the mah capacity is

4.15v



after 100 cycles **** didnt realise starting voltage is 4.2v instead of original 4.191v******



4.1v



after 100 cycles



4.05v



after 100 cycles



4.0v



after 100 cycles



3.9v



after 100 cycles



3.8v



after 100 cycles



3.7v



after 100 cycles



3.6v



after 100 cycles



3.5v



after 100 cycles



3.4v



after 100 cycles



3.3v



after 100 cycles



3.2v



after 100 cycles



i consider this cell done at 3.2v

not sure what is going on with this battery but at 3.55v its at 3650mah. im wondering if its similar to the 26800 that stops at 3.0v

https://endless-sphere.com/forums/viewtopic.php?f=14&t=98327

heres a different view 3.5v/4200mah

going to start setting up the discharge and im going to use cell temperature for my cut offs at different discharge rates

10amp was 85f at 3.6v, the test started with a cold battery, id rather see 95f



7.5amp was 95f at 3.4v



5amp was 92f at 3.3v



2.5amp was 85f at 3.25v



volts bounced back to 3.411v after discharge stopped

youtube video of dead shorting a mnke 26650

https://www.youtube.com/watch?v=nL2TT3darhY

as the battery cycles, the cycle temperatures drop a little bit. i noticed the mah has been increasing. the charge has increased by 1mah/cycle over the last 3 cycles.

the charge temps have decreased by 2f. when charge mah starts losing again ill recheck battery charge temperatures to get the range.

this is where i bought the battery, they call it a 20amp cell

https://18650canada.com/collections/26650/products/mnke-5000mah-26650

i test the battery in a cardboard box so i can play with battery temperatures without disrupting the settings



i put a weight on top and it increased peak temp to 101f



#15 discharge mah increased to 4974mah



put a towel over the box to raise temperature some more to see what happens

#16 charge 4913mah, discharge 4982mah



start of 17 charge was 85f, charge 4922mah, discharge 4988mah, peak temp 102f

start of 18 charge was 86f, charge 4928mah, discharge 4993mah, peak temp 102/3f

start of 19 charge was 86f, charge 4928mah, discharge 4989mah, peak 102/1f

this battery is pretty impressive, i came into this thinking the 26650 cell was too fat to shed heat and would overheat easily but it sheds its heat as soon as the amps stop.

might do 1 discharge at 6.5amps continuous to see temperature and capacity

heres 6amp to 3.3v, battery temp reached 94f and volts bounced back to 3.548v after sitting

raised battery temperature by lowering the 10amp &7.5amp cut off by 0.02v. peak temps are 101f/38celsius.



#26 charge 4908mah, discharge 4978mah

did a 6.5amp continuous discharge, i got distracted and didnt get the peak temperature but it was less than 100f. it was a steady 97f with 5minutes left. might try 6.8amps next time

from cycle 50 to cycle 65 the battery was losing alot of mah per cycle. i changed step 2 charge amps from 3.75 to 3.0 amps.
the battery has gained/recovered 12 mah in the last 4 cycles since i made the change. might lower it to 2.5amp charge.

i should do a 0.8amp discharge capacity test to see where the damage/loss is

did the 4.2v to 3.2v discharge for 100 cycles and posted at start of thread

the higher charge was hurting it and did better at 3amps, going to change charge to 2.5amps for a dozen cycles to see the result and then ill eliminate 10 amp discharge for a dozen cycles to see result then ill be testing another battery,

i just wanted to have a look at this battery to see how it compares to a battery like a 40T and a P42a

i also posted the mah at different voltages to compare with the earlier readings, thats in this post

https://endless-sphere.com/forums/viewtopic.php?f=14&t=107191&p=1569025#p1569032

i made changes to the charge at #107 because it was losing 6mah/cycle



#107 charge 4676mah discharge 4741mah



#110 charge 4658mah discharge 4727mah



#113 charge 4667mah discharge 4733mah



ill let this cycle a few more times before removing the 10 amp discharge,i was looking at discharge graphs of other 26650 cells and i think 7.5amp might be the max discharge for cycle life of this cell.

i removed the 10amp discharge and the battery improved but the charge seems to be the problem. ive lowered the charge amps to 2 amps to see if it helps. the temperature at start of charge is 85f.
ill let these settings cycle til tomorrow before i start changing charge temperatures

cycle #124



#124 charge 4640mah discharge 4706mah
#125 charge 4641mah discharge 4705mah
#126 charge 4638mah discharge 4706mah
#127 charge 4638mah discharge 4705mah

that seems to be working better

before changing start of charge battery temperature i want to do a few cycles with 10 amp discharge reintroduced with the 2amp charge to check mah loss per cycle



#131 charge 4631mah discharge 4703mah
#132 charge 4638mah discharge 4707mah
#133 charge 4643mah discharge 4705mah

start of charge for #134 was going to be 87f after the 5 minute wait so i stopped the test for another 5 minutes til temp reached 85f

#134 charge 4642mah discharge 4704mah

going to drop start of charge to 82f for #135, took 25 minute wait time

#135 charge 4638mah discharge 4699mah
#136 charge 4631mah discharge 4694mah
#137 charge 4629mah discharge 4698mah

im just playing with whether its better to charge a battery right after the ride when the battery is still warm or wait until just before using battery to charge when its at room temperature, need to get temperature down to about 70f. ill change wait time to 59 minutes for #138 and let it cycle a few times. start of charge was 74f

#138 charge 4631mah discharge 4694mah
#139 charge 4629mah discharge 4698mah
#140 charge 4632mah discharge 4696mah
#141 charge 4626mah discharge 4690mah
#142 charge 4623mah discharge 4688mah

removing the 10amp discharge for #143 and cycle 10x, start of charge is still 74f

#143 charge 4627mah discharge 4695mah
#144 charge 4632mah discharge 4702mah
#145 charge 4638mah discharge 4706mah
#146 charge 4638mah discharge 4701mah
#147 charge 4633mah discharge 4696mah
#148 charge 4630mah discharge 4699mah
#149 charge 4638mah discharge 4702mah
#150 charge 4641mah discharge 4704mah
#151 charge 4637mah discharge 4698mah
#152 charge 4629mah discharge 4692mah
#153 charge 4626mah discharge 4688mah
#154 charge 4624mah discharge 4694mah
#155 charge 4631mah discharge 4696mah
#156 charge 4631mah discharge 4689mah
#157 charge 4620mah discharge 4679mah

it takes 4.5hrs/cycle, house temp fluctuates, #149 was over at 6pm and #150 started charge at 7pm. you can see in the mah #'s that the mah drops overnight and increases through the day. if i look back about 24hrs/5cycles and compare mah the battery is losing about 0.4/0.5 mah/cycle. after #157 ill raise charge temperature again to double check before ending this thread.

had computer issues today, had to download Phaserunner Software to laptop to change settings to bike, when i opened phaserunner suite it connected to EB tester software and wiped out the test data. i dont have cycle 158,159 or 160. im going to do the 0.8amp discharge and put the test on hold. have another battery test to do.

did the 4.2 to 3.2 capacity discharge

discharge 100 was 5172mah
discharge 160 was 5109mah

battery lost 63mah over 60 cycles but didnt make changes to charge until around cycle 125.
its doing alot better with a 2 amp charge and removing 10amp from discharge.

charged battery to 3.6v and put it on shelf to do more testing later.

its been 37 days, battery was at 3.585v, charged it up



im using these settings



heres discharge



im short listing some cells for a pack build and i want to see where the volt sag to 3.2v under 5amp discharge is. im just doing a few cycles to get it active then ill check the sag

peak discharge temp 99f

#161 d-4883, c-4805
#162 d-4873, c-4796
interesting, the last numbers for cycle #157 d-4679, c-4620
#163 d-4867, c-4789
#164 d-4858, c-4777
#165 d-4848, c-4770
#166 d-4842, c-4768
#167 d-4844, c-4769
#168 d-4841, c-4770
#169 d-4848, c-4768
#170 d-4836, c-4759
#171 d-4828, c-4753 going to give the battery a break, it was going steady for about 30hr til #169 dropped 12mah

battery had a 48hr break, i checked my tester with another battery to make sure the 12mah drop at #169 wasnt the tester acting
up. its 8pm Sept.11 and cycle #172 started. i want to see how many hours/cycles til battery acts up again

#172 d-4870, c-4791
#173 d-4850, c-4771
#174 d-4835, c-4763
#175 d-4828, c-4753
#176 d-4819, c-4746
#177 d-4819
giving battery 24hr break, its sept.12/6pm. sept.13 7pm test resumed
#178 d-4835, c-4760
#179 d-4811, c-4745
#180 d-4812, c-4739
#181 d-4818, c-4745
#182 d-4827, c-4755
#183 d-4833, c-4754
#184 d-4827 stopped test 10:30pm sept.14

sept.16, 8:30pm discharge started, ill stop test after discharge #190 for another 48hr break
#185 d-4872, c-had an issue
#186 d-4874, c-4747
#187 d-4824, c-4743
#188 d-4822, c-4741
#189 d-4820, stopped test 9:50pm sept.17 for another 48hrs

sept.19/8pm discharge start
#190 d-4832, c-4756
#191 d-4824, c-4745
#192 d-4813, c-4736
#193 d-4805, c-4729 peak battery temp was 97f. raising temp
#194 d-4803, c-4726 peak temp 101f
#195 d-4803 stopped test 6pm sept.20 for 48hrs

sept.22/ 9pm discharge started
#196 d-4838, c-4763
#197 d-4819, c-4743
#198 d-4811, c-4731
#199 d-4810, c-4736
#200 d-4805, c-4732
stopped test for a month on sept.24. stored at 3.653v

i want to see volt sag at 5amp discharge to 3.2v to see what the volt sag and mah is if i use full throttle with a dead battery.
peak temp was 95f, volts bounced back to 3.447v and 4529mah

im going to play with this battery for a little bit

it reminds me of when Okashira was testing the 30q and Tesla cell and "self healing" of tesla battery

https://endless-sphere.com/forums/viewtopic.php?f=14&t=68556&p=1159167&hilit=self+healing#p1159167

the 0.8amp discharge capacity test results after #of cycles
#000-5308mah
#100-5172mah
#160-5109mah
#172-5098mah
#201-5099mah

battery has been sitting 3 months, guess i left it fully charged because it read 4.169v

want to see if its possible to "desulfate" it

it already shows self healing

heres #202 discharge curve



#202 mah by step



heres the previous numbers

#196 d-4838, c-4763
#197 d-4819, c-4743
#198 d-4811, c-4731
#199 d-4810, c-4736
#200 d-4805, c-4732
new numbers
#202 d-4877, c-4726
capacity test
5273mah
#203 d-4844, c-
desulfate doesnt work

1amp discharge capacity test from 4.2v to 2.5v= 5273mah