Roomba Charging data Info

[vic7767]

While capturing charging data on the OSMO'ed Roomba Red with an APS battery my first observation was that the charging system was not as aggressive on the battery as the Scooba charging environment. I left the monitor on and thanks to davem's suggestion there was no interruption the the logging information, here's what happened at minute 807.

bat: min 807 sec 0 mV 16977 mA 293 deg-C 60
bat: min 807 sec 1 mV 16977 mA 306 deg-C 60
bat: min 807 sec 2 mV 16977 mA 299 deg-C 60
bat: min 807 sec 3 mV 17005 mA 293 deg-C 60
bat: min 807 sec 4 mV 16977 mA 286 deg-C 60
bat: min 807 sec 5 mV 16977 mA 286 deg-C 60
bat: min 807 sec 6 mV 16977 mA 293 deg-C 60
charging-done: temperature max allowed @ minutes 807
do-charging-wait-for-trickle @ minutes 807
bat: min 807 sec 7 mV 16921 mA -46 deg-C 60
bat: min 807 sec 8 mV 16894 mA -52 deg-C 60
bat: min 807 sec 9 mV 16866 mA -52 deg-C 60
bat: min 807 sec 10 mV 16866 mA -52 deg-C 60
bat: min 807 sec 11 mV 16866 mA -52 deg-C 60
bat: min 807 sec 12 mV 16866 mA -52 deg-C 60
bat: min 807 sec 13 mV 16866 mA -52 deg-C 60
bat: min 807 sec 14 mV 16866 mA -52 deg-C 60

This battery is being cooked just like the scooba battery, it just gets accomplished in a more gradual manner.

[Gordon]

While capturing charging data on the ... Red ... my first observation was {it} was not as aggressive on the battery as the Scooba charging environment.

Yes, I think we could anticipate that would be the case, simply because more energy must be stuffed back into a Scooba battery in about the same period we are used to seeing a Disco re-charge.

..., here's what happened at minute 807.

Question on that time period -- did that battery actually take 807 mins / 60 mins_per_hr = 13+ hours to reach the fully charged state?
Also, FYI, my 4210's APS batt finishes, to supply a {post-charge} level of {minus}44mA {...}. I wonder what's going on there(?) maybe it'll flip over after temperature falls down from that high 60C. {I'll leave it connected and check on the 3rd}.
(Before I bet money on my stated polarity, I need to do a wiring check inside my battery break-out box; {I did and found meter polarity reversed.}).

This battery is being cooked just like the scooba battery,...

{...I'll judge mine on the 3rd}.
{Edited to correct naff info.}
Added on the 3rd, mid-day: The battery is now trickle-charging at 56mA, and its case (while in the robot), feels just barely warmer than body temperature -- I would guess 39 or 40C. This should not be a "cooking issue".

[vic7767]

Yes it did actually take until min 807 to reach the fully charged state. It continued not charging until:

bat: min 926 sec 55 mV 16086 mA -52 deg-C 45
bat: min 926 sec 56 mV 16086 mA -52 deg-C 45
bat: min 926 sec 57 mV 16086 mA -52 deg-C 45
bat: min 926 sec 58 mV 16086 mA -52 deg-C 45
bat: min 926 sec 59 mV 16086 mA -52 deg-C 45
do-charging-trickle @ minutes 927
bat: min 927 sec 0 mV 16086 mA -39 deg-C 45
bat: min 927 sec 1 mV 16114 mA 52 deg-C 45
bat: min 927 sec 2 mV 16114 mA 39 deg-C 45
bat: min 927 sec 3 mV 16114 mA 46 deg-C 45
bat: min 927 sec 4 mV 16114 mA 46 deg-C 45
bat: min 927 sec 5 mV 16142 mA 59 deg-C 45
bat: min 927 sec 6 mV 16142 mA 52 deg-C 45
bat: min 927 sec 7 mV 16114 mA 46 deg-C 45
bat: min 927 sec 8 mV 16142 mA 52 deg-C 45
bat: min 927 sec 9 mV 16142 mA 46 deg-C 45
bat: min 927 sec 10 mV 16142 mA 59 deg-C 45

I'm thinking that once the battery reached C 60 charging stopped. I don't understand the -52 mA but all that I'm doing is capturing the ascii data that is being output from the SCI port. It also seems the charging starts back up once the battery has cooled down to a predetermined temperature of C 45. So evidently the roomba charging system is not as aggressive as the scooba charging system and can therefore be left connected and charging for a much longer period of time. Now that my monitor system behaves with no interruptions I'm going to monitor the Scooba batteries in a more detailed manner. Once that is done I'll post here if needed.

[mfortuna]

The negative current is simply the battery not being charged. The roomba is consuming 52 mA while idle.

We need a data collection of a mostly empty pack being charged on a scooba. The roomba data looks OK since the recommended trickle charge rate is not exceeded. I don't like the 60C reading though.

I'm surprised the irobot battery charger algorithm isn't more simple. The fact is that a pack that shows a heat increase and voltage drop is charged.

You can peak the battery every hour at high current but if the voltage drops or temp increases go back to trickle.

Mike

[vic7767]

Thanks Mike, that makes sense about idle current. I've got 3 Scooba batteries to test with. One has been off of any charging environment for about a week. Do you or Gordon have an idea of what cell voltage I should test for before starting the charging, logging tests again?

[Gordon]

..Do you or Gordon have an idea of what cell voltage I should test for before starting the charging, logging tests again?

We have been told (by iRobot CS Mgr.) that Roomba uses a 12-volt cut-off, to indicate it has exhausted all reasonable charge. On that basis, the mean cell voltage would be one volt.
And that is quite reasonable, because further attempts to take more energy out of the battery would result in a rapid fall of terminal voltage.

[Gordon]

The negative current is simply the battery not being charged. The roomba is consuming 52 mA while idle.
...

Mike, lest owners get the idea that a Discovery's Standby Current Drain is 52mA, (I knew it to be less so...) I just re-measured the quiescent current draw in my 4210, and confirm it is only 7mA (rounded to nearest mA).
My Pro-Elite Roomba used only 5mA.
These are the currents needed to keep the top-mounted IR-receiver biased, and the MCU in a state in which it can respond to a remote-control signal beam.

[mfortuna]

That what the roomba is reporting, maybe the measurement is not accurate or reflects a lower voltage at higher current point which is effectively the same number of Watts.

Mike

[Gordon]

That what the roomba is reporting, ...

I am in agreement with that. The Standby Current I refer to is battery load measured without the charging power supply connected to the robot.

[vic7767]

I think we can also consider that the Rootooth device plugged into the SCI port is also consuming a little current.

[Gordon]

Very good vic, I think you spotted it. That Rootooth must be pulling 35 to 40mA!

[fergambo]

Hello. I know this an 'ancient' thread, but it's the only one I found about Roomba charging data info.

Three wekks ago ago I bought the sixth (iRobot X-life 3000 mAh) battery for my 560, and by means of a USB serial I'm trying to discover why my 560 seems a battery destroyer...

This was the log of one of the first (9th Nov) charges of my new 3000 mAh battery
...
bat: min 4603 sec 33 mV 17673 mA 1188 tenths-deg-C 516 mAH 2626
... (last minute)
bat: min 4604 sec 33 mV 17645 mA 1180 tenths-deg-C 525 mAH 2626
charging-done: temperature slope @ minutes 4604
do-charging-waiting-trickle @ minutes 4604

Only 2626 mAh, and charge ended due to temperature increased more than 0.5°C in the last minute. OK.

But this was the log of yesterday charge, only 1761 mAh, and no any charge during the last hour...

... (The last mAh charged...)
bat: min 2005 sec 51 mV 16949 mA 1070 tenths-deg-C 338 mAH 1760
bat: min 2005 sec 52 mV 16949 mA 1070 tenths-deg-C 338 mAH 1761
... (62 min whith no any mAh...)
bat: min 2067 sec 11 mV 17673 mA 1031 tenths-deg-C 445 mAH 1761
.... (last minute)
bat: min 2068 sec 11 mV 17673 mA 1031 tenths-deg-C 454 mAH 1761
charging-done: temperature slope @ minutes 2068
do-charging-waiting-trickle @ minutes 2068

Same end charge ended due to Temperature increases more than 0.5°C in the last minute)

After this I reseted Roomba and:
...
do-charging-checking-fets @ minutes 0
bat: min 0 sec 1 mV 16532 mA 8 tenths-deg-C 376 mAH 2696
Charging FET test passed.
...
bat: min 0 sec 2 mV 16782 mA 578 tenths-deg-C 376 mAH 2696
...
bat: min 15 sec 41 mV 17812 mA 1031 tenths-deg-C 453 mAH 2696
charging-done: voltage dip @ minutes 15
do-charging-waiting-trickle @ minutes 15

My questions are:
- How is the 'minutes' number? The only I see reseting Roomba, time is reseted too
- 'Voltage dip', is voltage dips more than a 30 mV from the maximum voltage. What is this??
- After resetting, Roomba considers 2696 mAh, so is useful to reset?? It seems no extra charge is done
- And how and is possible in three weeks my new baterry only charges 1761 mAh...

Any orientation will be much appreciated.. Thanks

[vic7767]

What firmware version is your 560 running? This 560 may need an OSMO flash.

[fergambo]

My firmware is 03 2008-05-28-1341

I found an 2012-03-22-1549 OSMO and now is travelling from UK, probably I'll get next week

Ok, I need this OSMO, but the first and second iRobot NiMH batteries life were two years, and now it seems I lost the 50 % in three weeks, so or new batteries are less apppropiate for old firmware, or something Changed in my Roomba....

[vic7767]

It is possible that the batteries are low quality. Have you thought of getting a LI-NMC lithium 4400 mAH battery?

[fergambo]

From I bought my Roomba 560 in 2009, previously to this last one, I've used five batteries, and the three no iRobot ones including a NewPow Lithium has been a disaster, 12 months of life.

[redpoint5]

I bought a used lithium battery from vic like 5 years ago for my 535, then accidentally forgot to remove it while the robot sat for about a year, and just last night I found it and charged it back up. Works fantastic. I'll have to see how much capacity remains. I'd probably have gone through 5 battery packs in the time this one has lasted.