DR1000 Batteries for DR1000

[papata]

Battery Replacement:
CameronSino Technology
ItemNo.: CS-IQN600SL
Volts: 3.7 V
Type: Li-Polymer
Capacity: 1500 mAh

Period of use test:
--------------------------
Charging Time – Overnight
Use Start Time - 12:40
Use End Time - 01:10
--------------------------
Total - 12 h. and 30 min.
--------------------------

No warning has been given before the switching off the device, which is what the Irex used to do with the original Varta. Secondly, the screen stayed on the last page although the device itself did not function from that point of time onwards. Obviously the battery still had powers to feed the device, which is why the screen did not go blank. So the Battery itself could have powered the device for some extra time, and it is not completely drained on the hanging event.

I am not sure that this can be adjusted by a hack in the setting of the device, but there is obvious mismatch between how the device behaved with the original Varta.
Although the screen was still showing the last page which was loaded before the hang-up, I could not reset it through the reset switch on the bottom. It needed a recharger to be plugged in before it can start again. I am not complaining though, I have got nearly 13 hours of continuous use and even with the annoying hang-up on the end, the device is much more useful than with a nearly dead Varta on board.
Thanks for the tips on replacing the battery Guys.

[Mackx]

Originally Posted by papata

No warning has been given before the switching off the device, which is what the Irex used to do with the original Varta. Secondly, the screen stayed on the last page although the device itself did not function from that point of time onwards. Obviously the battery still had powers to feed the device, which is why the screen did not go blank. So the Battery itself could have powered the device for some extra time, and it is not completely drained on the hanging event.

An e-ink screen does not need power to retain its information. So if you cut of the power, the last information on the screen will stay there.

Originally Posted by papata

I am not sure that this can be adjusted by a hack in the setting of the device, but there is obvious mismatch between how the device behaved with the original Varta.
Although the screen was still showing the last page which was loaded before the hang-up, I could not reset it through the reset switch on the bottom. It needed a recharger to be plugged in before it can start again. I am not complaining though, I have got nearly 13 hours of continuous use and even with the annoying hang-up on the end, the device is much more useful than with a nearly dead Varta on board.
Thanks for the tips on replacing the battery Guys.

Normally the battery charger/monitor needs to 'learn' how the battery behaves, so it is possible that after a few charge/use cycles the indication of the power left in the battery will be more accurate. But then it could also be that some special parameters need to be configured in the charger-chip to match the used battery, time will tell.

[papata]

, you are right the device has learned how the battery behave and now is giving the empty battery warning as it was before. All in all I will post another reply measuring the battery life after five successive charging. But so far it seems that the battery is quite capable of doing over 14 hours of use. Thus I think it is better than the original battery and there is no hassle with the dimensions at all.

[Mackx]

[DARE DEVIL MODE]If you are using the dr1000-hackx firmware patch/hack you can create an empty file called log.txt in the root of your SD-card. Some extra information on the status of the battery will be logged there. There is no tool to make sense of the data that is logged, so you have to look into the code and figure out yourself (sorry) (added: see this changeset).
By removing the file (when the DR is turned off) logging should stop.[/DARE DEVIL MODE]

[MrWarper]

Hi Mackx!

Well, as I said here a minute ago I've finally replaced my old battery with a newer, larger one, and I'm experiencing some issues with the battery gauge getting used to the new battery. So I entered 'Daredevil mode' and now I have a growing log.txt that goes like this:

1347652083:PB;
1347652086:B2,5;
1347652104:B2,5;
1347652119:PI;
1347653066:PNI;
1347653066:B2,38;
1347653066:B2,38;
1347653072:PI;
1347653180:PNI;
1347653180:B2,39;
1347653180:B2,39;
1347653186:B2,41;
1347653190:PI;
1347654217:PNI;
1347654217:B2,63;
1347654217:B2,63;
1347654223:PI;
1347654505:PNI;
1347654505:B2,67;
1347654505:B2,67;
1347654511:PI;
1347654512:PNI;
1347654512:B2,67;
1347654517:PI;
1347656779:PNI;
1347656779:B2,100;
1347656779:B2,100;
...

It doesn't look too complicated, so care to explain what it all means so we can learn how the battery gauge adapts to a newer one, without perusing the code ?

I'll guess the first numeric blob is some sort of time code, and the last one charge percentage either as reported or calculated...

[Mackx]

Short answer:
I also do not know exactly anymore, I need to dive into the code for more details.

From my memory:
PB: boot
PI: go to idle(low-power)
PNI: come out of idle
Bx,y: x: state charging, discharging, y: percentage reported by battery driver

The timestamp is a unix timestamp (seconds since 1/1/1970)

[Mackx]

There are also PF: power off end CU: card unmount.

Did you learn anything from the logging?

[MrWarper]

Originally Posted by Mackx

There are also PF: power off end CU: card unmount.

Noted, thanks.

Did you learn anything from the logging?

I haven't analyzed it in any depth yet.

My 'larger capacity' replacement battery has been stuck at 4+ hours discharge time for 'ages' now, so either it is damaged (I have reasons to think this is not unlikely), my work DR is (but I don't think so - it works flawlessly otherwise), or for whatever reason it can't adapt to a new battery. I've just put in my last spare battery (original type) and if that works OK I'll try another replacement battery when this one wears out, or sooner if it doesn't.

Meanwhile I am open to discussion. Do you think I'll need a few charge/discharge cycles again at this point? Just when exactly it is expected to be necessary?

[MrWarper]

Well, this is not based on my analysis of battery logs, but I think now I know how to make things work, and I have the log of what I did, so one thing can be checked against the other. Plus, I'll do it again soon just to check if I'm right and I'll log it again, so both experiences can be analysed under the light of the logs by those so inclined (sorry, but if something works for me in an apparently logical way, that's enough for me).

So... my original DR1000 battery was down to ~4hours of use, I replaced it with a higher capacity one and after one promising cycle of 18hours of 'work' with incorrect battery readings (in the end it wouldn't power on because the battery was completely discharged but the gauge kept reporting 100% till the very end) I was back to ~4hours cycles after that. That larger battery might have been damaged, so I put another DR1000 original type one and I was stuck with cycles of very similar length again.

Now I deem extremely improbable that any two random batteries can have so similar charge/discharge cycles so I concluded I wasn't doing it right.

What did I do in the end? First I set the DR1000 to never power off. I let the battery discharge completely every time, until the red light turned off (but not longer, to prevent overdischarging from damaging the battery), and charged it for a little while after reaching 100%. Now I'm back to ~12-hour cycles.

I assume the gauge gets used to the battery lifespan shrink over time, and when you put in a larger capacity / newer one it needs to go beyond its now-usual discharge curve to learn that the new battery still draws power...

Now that I got this working I'll try the same with that larger capacity battery I have, to check this is actually how the gauge works (and if the battery is actually damaged or not) and establish once and for all that it is feasible to use such batteries with the DR1000. I'll post the log for that here, but the post will go in this other thread about DR1000 and batteries.

[MrWarper]

This is it, see the attachment. I've mostly let the DR1000 run out of battery and charged it back again until the low battery warning occurred soon before actually the reader actually ran out of juice. Sometimes I was busy and let it discharge for too long so the time setting got reset back to around 2010, you can see that in the logged timestamps. I'll publish another log for the 2400 mAh battery, possibly next week.

[papata]

Hi Guys,

I hated the constant playing up of the Irex DR1000 recently.

Pretty much the behavior was the same as the experience of MrWarper, and the fact that I have to watch constantly for not over discharging the device battery. Thus, I have decided to change the battery to something closer or identical to the original one which was according to Varta is 1300 mAh.
http://www.farnell.com/datasheets/89136.pdf

The new replacement battery is yet another Cameronsino product :

ItemNo.: CS-TM920SL
Volts: 3.7 V
Type: Li-Polymer
Capacity: 1300 mAh
Dimension: 60 x 37 x 6 mm

The Battery is in fact more like 5 mm thick, or the same thickness as the previous two batteries used, and it fits perfectly without any alterations of the casing.

I don't like, and I am pretty fed up with the constant playing up of the device with the 1500 mAh of the previous CS battery, although it was nice from time to time to have 12&1/2 hours of use without charging.

However, the device is constantly being over discharged and its behavior is as if the battery is constantly full, where in fact was less than a half discharged.

I will try to keep you updated on the behavior of the Irex DR1000 with the new CS-TM920SL.

BTW, CS are no longer making the 1500 mAh model and are stating that the CS-IQN600SL model is now 1150 mAh instead of the extended 1500 mAh, which I had in the Irex DR1000.

[papata]

Now I am convinced the DR1000 is actually “she”, and she is so fussy that it only takes the right size to make her happy…

Jesus, if I only knew that earlier…wouldn’t have wasted so much time.
Guys just don’t bother with anything else but 1300 mAh batteries, if you of course want trouble free use. “She” is like brand new…and since “she” is happy with the replacement battery and everything seems to be working as before, I am too.

[Mackx]

Looking in the source code of the DR, there seems to be a gasgauge IC on the DR1000 (kdbupgrade.c). The gasgauge ic probably contains its own CPU which needs to be programmed to monitor the charge/dis-charge cycles of the battery (The source code uses a block of 1024 bytes that needs to be transferred to the gasgauge ic). I assume that this program (or its parameters) are tuned for the specific battery used by the DR. So using a battery that is different enough from the original battery probably will not work. Which is in line with the outcome of the experiments described in this thread.
Unfortunately the pictures on http://dr1000s.blogspot.nl/ do not show anymore, so I could not find any details w.r.t. the used gasgauge ic.

[MrWarper]

After a veeeery looong test period, I have now an enormous log of the charge / discharge cycles of my large (2400mAh) battery. I'll post it here tomorrow as an edit, after one last discharge period.

My conclusions:
-It is currently not possible to make the DR1000 work with battery capacities larger than the original (1300 mAh).
-Its charge gauge adapts very well to batteries of that or lesser capacity, which makes sense, because batteries are expected to diminish their capacity over time and be replaced at some point.

Working with a 2400 mAh battery I've observed three different behaviours:
-The DR1000 will discharge for ~12.5 hours and will give its low battery warning, and lit the red led. It will sit like that for another ~12.5 hours before actually running out of power.
-The device will report 100% battery for ~12 hours, and then will report a 'normal' discharge over the next 12 hours.
-It will discharge over the course of 12 hours as if the battery were the original one, then will do another identical cycle if restarted.
Since I haven't find a method to reliably make it work like cases 2 and 3, the idea of sticking a larger capacity battery in the reader is not very practical... yet

Originally Posted by Mackx

Looking in the source code of the DR, there seems to be a gasgauge IC on the DR1000 (kdbupgrade.c). The gasgauge ic probably contains its own CPU ...
Unfortunately the pictures on http://dr1000s.blogspot.nl/ do not show anymore, so I could not find any details w.r.t. the used gasgauge ic.

But dear friend, you have me here. What do you think the numbers and xs below my name, where it says 'device', mean? Here you have a couple of pictures of a DR1000 board, and I'm ready to do all the experiments you want. The only problem is I can't take very good pictures with my mobile phone, so you'll have to guide me 'a little'.

Assuming the IC you mention is the little black square below and a bit to the left of the battery plug socket (ivory square next to the right edge) in the second picture, it has 14pins (7 going up, 7 down), is labelled as U25 or U35 on the board, and it also has the number 6 to one side. On top of it there's three lines -- 1: 4085; 2: N7347; 3: LT90. If you need whatever else, just send me a PM...

[Mackx]

I googled a little bit and U59 seems to be a bq27500 from TI.

The bq27500/1 accurately predicts the battery capacity and other operational characteristics of a single
Li-based rechargeable cell. It can be interrogated by a system processor to provide cell information, such
as state-of-charge (SOC), time-to-empty (TTE) and time-to-full (TTF).

I had a quick look at the datasheet at it seems to be a very complex device that can (must?) be tuned to a specific battery by programming a lot of registers via I2C.