Molicel P42a cycle test

Batteries, Chargers, and Battery Management Systems.
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goatman   10 MW

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Molicel P42a cycle test

Post by goatman » Aug 01 2020 12:38am

4.2v to 2.5v, 0.8amp discharge capacity test

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#100

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wider view

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#100

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Last edited by goatman on Aug 13 2020 10:16pm, edited 3 times in total.

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 01 2020 12:39am

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discharge 3516mah, charge 3468mah

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Last edited by goatman on Aug 01 2020 5:55pm, edited 1 time in total.

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 01 2020 12:39am

setting each discharge amp cut off settings by battery temperature

starting temp was 75f

10 amp cut off at 3.58 volts, battery temperature 94f, 1049mah

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7.5 amp cut off at 3.39 volts, battery temperature 101f, 1137mah

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5 amp cut off at 3.30 volts, battery temperature 95f, 817mah

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2.5 amp cut off at 3.20 volts, battery temperature 87f, 538mah

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Last edited by goatman on Aug 01 2020 12:04pm, edited 6 times in total.

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 01 2020 12:39am

starting battery temperature 87f

2amp charge to 3.6v, battery temp was 79f at 3.6v, 460mah

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when 3.75 amp charge reached 4.2v battery temp was 88f, 2290mah

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end of charge temp 78f, 3035mah

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cycle #1 combined charge 3495 mah

something goofy happened with the 10 amp/7.5 amp discharge, you can see it in graph below. going to charge back to 4.2v and start again

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bad connection, problem solved

peak temp at end of 7.5amp discharge reached 104/5f, going to change cut off voltage to 3.55 volts to lower temperature

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volt sag with 10amp discharge

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Last edited by goatman on Aug 01 2020 10:01pm, edited 7 times in total.

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 01 2020 12:47am

magnets and copper slug tape

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battery arrived at 3.527v, charged with 2amps 0.10 c/o

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starting 4.2v to 2.5v capacity test at 0.8amp discharge

4.15v, 15mah

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4.10v, 95mah

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4.05v, 343mah

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100 cycles 323mah

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4.0v, 799mah

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100 cycles 759mah

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i just wanted to see where the mah starts

i got this battery from 18650 Battery but had a problem. they shipped the battery and it supposedly left Florida enroute to Canada June.14.

july.15 i sent 1 email with 3 words, Wheres my battery?
next day they replied, It seems to have been lost and weve sent you another battery

2 weeks later i had the battery. Excellent no BS customer service :bigthumb:
Last edited by goatman on Aug 12 2020 9:09pm, edited 2 times in total.

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 01 2020 10:46pm

for cycle 2 i tried to lower peak battery temp from 104f to 101f by changing 7.5 amp c/o to 3.55v from 3.39v, went too far but capacity improved

discharge 3567mah, charge 3516mah

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changed 7.5 amp c/o to 3.47v and the discharge is better balanced, peak temp was 100f a little less discharge mah. just going to let it cycle now

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#3 discharge 3554mah, charge 3508mah
#4 d-3545mah, c-3499mah
#5 d-3537mah, c-3492mah
#6 d-3531mah, c-3485mah
#7 d-3524mah, c-3478mah
#8 d-3519mah, c-3474mah
#9 d-3515mah, c-3471mah
#10 d-3512mah, c-3467mah
#11 d-3509mah, c-3463mah i changed 3.75a charge to 2.5amps for 12 and 13
#12 d-3506mah, c-3459mah
#13 d-3502mah, c-3455mah- put 3.75a charge back and changed wait time between discharge/charge from 5min to 10min
#14 d-3499mah, c-3456mah
#15 d-3499mah, c-3453mah
#16 d-3497mah, c-3451mah
#17 d-3494mah, c-3448mah
#18 d-3492mah, c-3445mah
#19 d-3488mah, c-3444mah
#20 d-3487mag, c-3441mah- changed wait time to 15min
#21 d-3485mah, c-3439mah
#22 d-3483mah, c-3439mah
#23 d-3482mah, c-3438mah
#24 d-3482mah, c-3437mah
#25 d-3480mah, c-3435mah
#26 d-3478mah, c-3434mah
#27 d-3477mah, c-3432mah
#28 d-3475mah, c-3430mah
#29 d-3473mah, c-3428mah
#30 d-3471mah, c-3427mah- changed wait time to 20min
#31 d-3469mah, c-3424mah
#32 d-3468mah, c-3422mah
#33 d-3466mah, c-3423mah
#34 d-3467mah, c-3422mah
#35 d-3466mah, c-3423mah
#36 d-3465mah, c-3424mah
#37 d-3467mah, c-3422mah
#38 d-3465mah, c-3419mah
#39 d-3463mah, c-3417mah
#40 d-3461mah, c-3415mah- changed wait to 30 minutes
#41 d-3459mah, c-3414mah
#42 d-3457mah, c-3412mah
#43 d-3457mah, c-3413mah
#44 d-3457mah, c-3413mah
#45 d-3456mah, c-3412mah
#46 d-3456mah, c-3411mah
#47 d-3455mah, c-3409mah
#48 d-3455mah, c-3407mah
#49 d-3451mah, c-3406mah
#50 d-3450mah, c-3403mah
#51 d-3448mah, c-3403mah
#52 d-3447mah, c-3401mah
#53 d-3445mah, c-3401mah
#54 d-3446mah, c-3394mah- 24hr wait between discharge/charge for #54
#55 d-3455mah, c-3410mah
#56 d-3452mah, c-3406mah
#57 d-3450mah, c-3404mah
#58 d-3448mah, c-3401mah
#59 d-3446mah, c-3400mah
#60 d-3444mah, c-3399mah
#61 d-3445mah, c-3397mah
#62 d-3444mah, c-3397mah
#63 d-3443mah, c-3397mah
#64 d-3443mah, c-3397mah- peak battery temp 99f
#65 d-3442mah, c-3395mah
#66 d-3441mah, c-3394mah
#67 d-3437mah, c-3392mah
#68 d-3438mah, c-3390mah
#69 d-3436mah, c-3389mah- changed to 45min wait
#70 d-3434mah, c-3387mah
#71 d-3433mah, c-3387mah
#72 d-3433mah, c-3387mah
#73 d-3432mah, c-3388mah
#74 d-3434mah, c-3387mah
#75 d-3432mah, c-3386mah
#76 d-3430mah, c-3383mah
#77 d-3429mah, c-3382mah- peak temp 97f
#78 d-3428mah, c-3381mah- raising temp
#79 d-3428mah, c-3382mah- peak temp 98f, raising temp more
#80 d-3428mah, c-3383mah- peak temp is still 98f, im using 1731mah at 10amps, ill insulate box to raise peak temp
#81 d-3429mah, c-3383mah- peak 100f
#82 d-3428mah, c-3382mah
#85 d-3425mah, c-3378mah
#90 d-3419mah, c-3375mah
#95 d-3407mah, c-3359mah
#99 d-3402mah, c-3356mah
switching back to 30 minute wait

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 13 2020 10:10pm

battery lost 149mah over 100 cycles

got rid of the 10amp discharge and changed wait time to 15min.

the battery had a day to sit idle before starting cycle 100 with new settings

discharge mah increased by 80mah????

#100 d-3482, c-3414mah

i dont have time to try and figure out why or how for a few days, going to let it cycle and see what happens. i wonder if continually cycling without a break affects it, maybe every 25 cycles it needs a day off?

#101 d-3457, c-3409mah
#102 d-3450, c-3399
#103 d-3441, c-3390
#104 d-3443, c-3384
#105 d-3427, c-3379
#106 d-3423, c-3373
#107 d-3420. c-3370
#108 d-3415, c-3368
#109 d-3411, c-3364
#110 d-3413, c-3363
#111 d-3410, c-3361
#112 d-3408, c-3358
#113 d-3407, c-3357
#114 d-3400, c-3353
august.15 quit testing

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Aug 31 2020 3:17pm

its been 2 weeks with the battery sitting and voltage dropped from 4.191v to 4.140v. topped off the battery so the testing would start at 4.191v.

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heres the chart with 10 amps removed

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#115 d-3375, c-3299
#116 d-3355, c-3304
#117 d-3357, c-3307
#118 d-3360, c-3309
#119 d-3360, c-3310
#120 d-3361, c-3311
#121 d-3359, c-3310
#122 d-3360, c-3309
#123 d-3360, c-3309
#124 d-3359, c-3310
#125 d-3360, c-3311
#126 d-3361, c-3313
#127 d-3362, c-3312
#128 d-3361, c-3312
#129 d-3363, c-3312
#130 d-3361, c-3312
#131 d-3361, c-3311
#132 d-3361, c-3310
#133 d-3360, c-3309
#134 d-3359, c-3310
#135 d-3350, c-3297
#134 d-3348, c-3299
#135 d-3350, c-3299
#136 d-3349, c-3299
#137 d-3348, c- after discharge, frign windows shut down computer next batch of numbers will be high than level off again but at
#135 the battery did behave odd, might need another break?

i charged battery with 2amps, 0.10c/o. 3294mah
let sit 5hrs and voltage dropped to 4.16v,
charged to 4.2v with 0.7amps, 0.10 c/o. 27mah

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#138 d-3369, c-3292
#139 d-3345, c-3294
#140 d-3346, c-3295 going to let it cycle til it acts up again
#141 d-3347, c-3299
#142 d-3349, c-3297
#143 d-3348, c-3297
#144 d-3347, c-3297
#145 d-3347, c-3295
#146 d-3344, c-3294
#147 d-3344, c-3293
#148 d-3343, c-3294
#149 d-3342, c-3291
#150 d-3343, c-3292
#151 d-3344, c-3293
#152 d-3343, c-3293
the software does 15 cycles at a time and stops. testing had stopped and battery voltage dropped to 4.17v so i topped up the charge, im going to change charge c/o amps to 0.05amps from 0.10 amps to see what happens on cycle #154
#153 d-3358, c-3293
software wouldnt let me go lower than 0.10 amps so dropped charge to 3amps from 3.75
#154 d-3353, c-3293
#155 d-3342, c-3292
#156 d-3342, c-3290
#157 d-3339, c-3288
#158 d-3338, c-3288
#159 d-3338, c-3288
#160 d-3338, c-3287
#161 d-3336, c-3287
#162 d-3337, c-3289
#163 d-3339, c-3289
#164 d-3338, c-3288
#165 d-3338, c-3286
#166 d-3336, c-3285
#167 d-3324 the battery just acted up with big mah drop. going to bring 10 amp discharge back

#120 was 3361mah and #166 was 3336mah for a 25mah loss over 45 cycles

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Sep 06 2020 12:19pm

heres the 10amp curve, peak battery temp 99f/37c

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#168 d-3341, c-3280
#169 d-3328, c-3280
#170 d-3328, c-3279
#171 d-3327, c-3278
#172 d-3327, c-3278
#173 d-3327, c-3277
#174 d-3325, c-3276
#175 d-3323, c-3274
#176 d-3322, c-3272
#177 d-3319, charged to 3.57v and put it on the shelf

i think im done testing this battery, if it cant handle 10 amps without losing less than 0.5mah/cycle, its not very good. 7.5amp seems ok

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Sep 24 2020 11:01am

im going to retest this battery for a few cycles. i saw the mnke 26650 battery didnt like to run constantly without suffering a big mah loss after about 24 hrs? plus the mnke and p42a didnt like to be cycled without an extended break between charge/discharge cycles. in the numbers above you can see where the battery "acts up"

The samsung 40T doesnt seem to care, gives consistent mah/cycle with short break and doesnt "act up".

what does that mean if a battery is in a solar system and what about regen on ebikes?

im going to play a little bit with this battery by giving it a break every 24hrs just to see what happens.
7.5/5/2.5 amp discharge, 2amp charge will cycle 10x then 24hr break

Image

#178 d-3334, c-3281
#179 d-3334, c-3283
#180 d-3335, c-3283
#181 d-3336, c-3283
#182 d-3335, c-3282
#183 d-3336, c-3281
#184 d-3332, c-3281
#185 d-3333, c-3279
#186 d-3331, c-3276
#187 d-3330, c-3278 sept.25/3:30 stopped test for 24hrs
sept.26/3pm discharge started
#188 d-3349, c-3261
#189 d-3318, c-3265
#190 d-3319, c-3270
#191 d-3324, c-3275
#192 d-3327, c-3276
#193 d-3328, c-3277
#194 d-3329, c-3279
#195 d-3329, c-3278
#196 d-3330, c-3278
#197 d-3331, c-3283, going to keep cycling til big mah drop
#198 d-3333, c-3285
#199 d-3335, c-3283
#200 d-3334, c-3284
#201 d-3332, c-3279
#202 d-3329, c-3276
#203 d-3326, c-3275
#204 d-3326, c-3273
#205 d-3325, c-3270
Last edited by goatman on Sep 29 2020 7:00am, edited 8 times in total.

Tommm   100 kW

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Re: Molicel P42a cycle test

Post by Tommm » Sep 26 2020 11:22am

goatman wrote:
Sep 24 2020 11:01am
im going to retest this battery for a few cycles. i saw the mnke 26650 battery didnt like to run constantly without suffering a big mah loss after about 24 hrs? plus the mnke and p42a didnt like to be cycled without an extended break between charge/discharge cycles. in the numbers above you can see where the battery "acts up"

The samsung 40T doesnt seem to care, gives consistent mah/cycle with short break and doesnt "act up".

what does that mean if a battery is in a solar system and what about regen on ebikes?

im going to play a little bit with this battery by giving it a break every 24hrs just to see what happens.
7.5/5/2.5 amp discharge, 2amp charge will cycle 10x then 24hr break

Image

#178 d-3334, c-3281
#179 d-3334, c-3283
#180 d-3335, c-3283
#181 d-3336, c-3283
#182 d-3335, c-3282
#183 d-3336, c-3281
#184 d-3332, c-3281
#185 d-3333, c-3279
#186 d-3331, c-3276
#187 d-3330, c-3278 sept.25/3:30 stopped test
From 3550 to 3330 in 185 cycles, 6.2% drop. If you drain the battery two times every week (one big ride during weekend and one big ride during the week, or several small ones). You are looking at 6.2% loss from using it for 2 years!! After that you only have to take care to store it at 50% or so. I think this battery can easily serve 5 years if used in the above way.

goatman   10 MW

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Re: Molicel P42a cycle test

Post by goatman » Sep 26 2020 12:24pm

i agree, im testing for myself and sharing. if you follow mooch i think he thinks? the p42a is better than a 40t for vaping. for my area i can get a 40t for $10 or a p42a for $11.50

im looking for a 10amp cell with a good life cycle and the 40T did alot better

also i can drain down a 40T, like riding to work and plug it in right away for charging but the p42a needed to sit for about an hour before charging
the p42a might do alot better if you let it sit like you mention

sept.26/3pm test resumed, the battery was cold, 70f when test started,

#188 d-3348, c-3261

cycle #206, wanted to see available capacity at 0.8amp discharge from 4.2v to 3.2v. 3472mah

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