maemo.org - Talk - Battery Tests, Homemade 3000mAh XL Battery & Q&A (POST #1)

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Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

mixing batteries of different capacity isn't good idea - higher cap battery will "charge" the lower one all the time, making it's current actually doubled. Generally, it's useless idea.

As for "batteyr bay" it's not a problem, when considering full-body replacement, I can make bay whatever I like.

dr_frost-dk, physically-wise, one single big cell *should* be best, but as we know, it's not always the case (2 scuds = more than one overpriced mugen battery, etc), so it can be 2 or 3 cells too, as soon as we gain capacity and capacity/price ratio :)

/Estel

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by Estel (Post 1216075)

mixing batteries of different capacity isn't good idea - higher cap battery will "charge" the lower one all the time, making it's current actually doubled. Generally, it's useless idea.

Well, will it really? When both batteries are in the same voltage level, I think they will not be different anymore after that if connected parallel and if not discharged to unhealthy empty stage. And if the voltage is not different, no current is from another battery to other.

And when charging all parallel connected batteries are charged to same max voltage?

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by peterleinchen (Post 1215818)

No!

Your output seems like towards full charged.
Please do the same for discharging and you will notice that your N900 "dies" with about 400-500 mAh left. Your capacity of 1741 looks like only one "full to empty" cycle.
You will need to recalibrate a few times. Recalibration starts from 2048/2056, when battery left out of N900 for few hours. And for each calibration (full empty with vdq=1) only 12,5% is cut. So just do a few more full "full to empty" cycles.

thank you!
had a suspicion of that & used it a couple times throughout the day without charging but didn't go down to the final drop :o
is that needed?
VDQ was 1 each time :confused:

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by zimon (Post 1216082)

No - cells of different max capacity will get different SoC after same mAh used. So, higher capacity battery will be constantly on higher voltage. As this situation is not possible for paralleled batteries, it will result in higher cap battery constantly charging lower capacity one, to compensate for above effect and maintain constant voltage for whole package.

Result - loses, additional heat, additional wear, and loses again.

/Estel

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by peterleinchen (Post 1215818)

just wondering...

did two cycles meanwhile
1st finished a little abruptly (red LED discharge wasn't installed & the sound was muted) but i had done a bq27000.sh without loop about ½ hr before battery run out
VDQ was 1 at that moment.
2nd cycle i caught the bq27000.sh with loop 0 about 5 min before battery went out...

Quote:

12:41 3445 29 29 -254 510 510 510 65535 120 31 0
LOOPMODE=0
Reading values...........................done.

CSOC: 29 % RSOC: 29 %
Average Current: 250 mA
TTF: 65535 minutes TTE: 122 minutes
NAC: 509 mAh CACD: 509 mAh CACT: 509 mAh
SI: 22 mA STTE: 1382 minutes
MLI: 1028 mA MLTTE: 28 minutes
AR: 0 mA ARTTE: 65535 minutes
Last Measured Discharge: 1740 mAh
Cycle Count since Learning: 8 Total Cycle Count since last full reset: 68
Reported Battery Voltage: 3459 mV
Battery Gauge die Temperature: 31 C
Flags: 0x04
Charge:0 NOACT:0 IMIN:0 CI:0 CALIP:0 VDQ:1 EDV1:0 EDVF: 0
eeprom data:
ILMD=2056 EDVF=3000 EDV1=3248 ISLC=20
DMF=14700 nanoVolt SD=201 thousandths of percent per day
AGELMD=1 TAPER=102 mA
IMLC=1028 mA
LOOPMODE=10
mv RSOC CSOC mA NAC CACD CACT TTF TTE TEMP EDV1 LOW
12:41 3443 29 29 -238 509 509 509 65535 128 31 0
12:41 3459 29 29 -220 508 508 508 65535 138 31 0
12:41 3453 29 29 -222 508 508 508 65535 137 31 0
12:42 3390 29 29 -407 507 507 507 65535 75 32 0
12:42 3319 29 29 -655 505 496 496 65535 46 33 0
12:42 3385 29 29 -369 504 496 496 65535 81 33 0
12:42 3327 29 29 -456 503 496 496 65535 65 33 0
12:42 3353 29 29 -396 501 496 496 65535 75 33 0
12:42 3364 29 29 -338 500 496 496 65535 88 33 0
12:43 3364 29 29 -333 499 496 496 65535 89 33 0
12:43 3332 29 29 -461 498 496 496 65535 65 33 0
12:43 3340 29 29 -441 497 496 496 65535 67 34 0
12:43 3332 29 29 -508 495 495 495 65535 59 34 0
12:43 3329 28 28 -357 494 494 494 65535 83 33 0
12:44 3364 28 28 -312 494 494 494 65535 95 33 0
12:44 3382 28 28 -161 493 493 493 65535 184 33 0
12:44 3390 28 28 -113 493 493 493 65535 260 32 0
12:44 3366 28 28 -299 492 492 492 65535 99 32 0
12:44 3382 28 28 -177 492 492 492 65535 166 32 0
12:44 3382 28 28 -112 491 491 491 65535 263 32 0
12:45 3319 28 28 -304 491 491 491 65535 97 32 0
12:45 3371 28 28 -111 490 490 490 65535 265 32 0
12:45 3377 28 28 -101 490 490 490 65535 290 32 0
12:45 3313 28 28 -271 489 489 489 65535 108 32 0
mv RSOC CSOC mA NAC CACD CACT TTF TTE TEMP EDV1 LOW
12:45 3271 28 28 -384 488 488 488 65535 76 32 0
12:45 3226 28 28 -292 487 487 487 65535 100 32 0
12:46 3319 28 28 -277 486 486 486 65535 105 33 0

& then recharge...

Quote:

LOOPMODE=0
Reading values...........................done.

CSOC: 29 % RSOC: 29 %
Average Current: 789 mA
TTF: 139 minutes TTE: 65535 minutes
NAC: 503 mAh CACD: 503 mAh CACT: 503 mAh
SI: 20 mA STTE: 1460 minutes
MLI: 1028 mA MLTTE: 28 minutes
AR: 0 mA ARTTE: 65535 minutes
Last Measured Discharge: 1740 mAh
Cycle Count since Learning: 8 Total Cycle Count since last full reset: 68
Reported Battery Voltage: 3739 mV
Battery Gauge die Temperature: 36 C
Flags: 0x80
Charge:1 NOACT:0 IMIN:0 CI:0 CALIP:0 VDQ:0 EDV1:0 EDVF: 0
eeprom data:
ILMD=2056 EDVF=3000 EDV1=3248 ISLC=20
DMF=14700 nanoVolt SD=201 thousandths of percent per day
AGELMD=1 TAPER=102 mA
IMLC=1028 mA
LOOPMODE=60
mv RSOC CSOC mA NAC CACD CACT TTF TTE TEMP EDV1 LOW
12:50 3770 29 29 776 509 509 509 142 65535 36 0
12:51 3831 30 30 795 522 522 522 136 65535 36 0
12:52 3712 30 30 467 527 527 527 232 65535 37 0
12:53 3876 31 31 812 540 540 540 132 65535 36 0
12:54 3889 32 32 783 552 552 552 138 65535 36 0
12:55 3892 32 32 783 566 566 566 133 65535 36 0
12:56 3889 33 33 791 578 578 578 132 65535 36 0
12:57 3897 34 34 771 591 591 591 135 65535 37 0
12:58 3903 35 35 779 604 604 604 130 65535 36 0
12:59 3905 35 35 743 617 617 617 135 65535 36 0
13:00 3911 36 36 753 629 629 629 132 65535 37 0
13:01 3916 37 37 793 642 642 642 124 65535 36 0
13:02 3924 38 38 804 656 656 656 120 65535 36 0
13:03 3934 38 38 806 669 669 669 118 65535 36 0
13:04 3937 39 39 795 682 682 682 118 65535 36 0
13:05 3945 40 40 786 695 695 695 118 65535 36 0
13:06 3950 41 41 791 708 708 708 117 65535 36 0
13:07 3958 41 41 791 722 722 722 115 65535 36 0
13:08 4008 42 42 970 736 736 736 93 65535 35 0
13:09 3974 43 43 779 752 752 752 114 65535 35 0
13:10 3977 44 44 850 765 765 765 114 65535 36 0
13:11 4024 45 45 949 780 780 780 90 65535 34 0
13:12 4029 46 46 958 796 796 796 88 65535 34 0
13:13 4032 47 47 958 811 811 811 87 65535 34 0

:confused::confused::confused::confused::confused: :confused::confused::confused:

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

I told you already (indirectly in my comment).
You will need to keep your N900 alive at a specific voltage (smth around 3200mV) for a specific time to let it register that it gets empty (with vdq=1).
Same happened to me few times, I needed days/weeks to get to my real capacity perfectly.
Just try to avoid heavy usage (even display light may be too much (depending on battery) on last mA or when near 3200mV; exact voltages you will find in dedicated post, where everything is explained exactly and in detail.

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by Estel (Post 1216217)

What is "SoC" here?

And "cells of different max capacity will get different SoC after same mAh used". But the smaller capacity battery is not giving as much currency as the bigger one, I think?

I am thinking of analogy of two water buckets, another one larger (mAh) than the other, but both have the same water level (voltage) and the level is at the same height (voltage). Both have same diameter (resistance) tube underneath going to the Y-connector and then the connecting tube is leaking water (current) out to somewhere.

I think, the buckets will be empty at the same time, and still no water is going from the larger bucket to the smaller one. (or there is an error in my thinking?)

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Seems like i should look in the drawer and find 2x Lixxx battery's of at least 50% difference in capacity and put this to the test.

Setup will be 2x battery's charged to 4.23V, then put together like the Dual Battery setup, then discharged to hopefully the combined capacity.

Both will be measured first for their TRUE capacity, will also discharge them at 2 different rates to see if a fast or slow discharge will get some diffident results.

Will post back when i get some results.

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by peterleinchen (Post 1217459)

thank you, followed your advice about taking the battery out completely for 24 hrs.
after putting it back in & did a heavy duty discharge & started using bq27000.sh (with loop 0 in order to see the VDQ:0 indeed)
initial the battery was seen having 2056 mA
after the 1st cycle it is already down to 1799 mA

will do another cycle tom'row

maybe the reinitialisation of the battery has to be complete (i.e. out of phone for 12 to 24 hrs)?

Re: Battery Tests, Homemade 3000mAh XL Battery & Q&A (GOTO POST #1) SCUD is BACK!!!

Quote:

Originally Posted by Estel (Post 1215799)

I'm investigating different possibilities for "best" battery to fit into N900's body replacement. 18650 sounds like sane choice, although, of course, we're "losing" a little - at least, theoretically - due to cylindrical form, and size (thickness) pose some problems too.

Reading the catalog of batteries from Panasonic, their largest-capacity flat (prismatic) cell, model UPF476790, is 3400mAh capacity with dimensions of 90mm height x 67mm width x 4.7mm thickness. You can browse their catalog of cells here which lets you sort by capacity, dimensions, weight, etc.: http://industrial.panasonic.com/www-...CA4000_WW.html

While flat batteries can make more complete use of available area inside the case, they tend to be less efficient in terms of energy density in the battery itself. So it is possible that given the same battery compartment, the 18650 with "wasted space" may still holding more energy than flat batteries which fill the whole compartment.

And, in other news, this week the Panasonic NCR18650B has been released, a single 18650 cell with 3400mAh capacity. :D