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[DragonGirl]

Hmm.  At first it was just a little unresponsive, very sleepy.  Batteries I say and get my other charged pack.
Put in new batteries, and runs fine for about 5 min, then halts mid action.
Apparently dead, I reboot, and then  begins reboot cycling maybe 10 seconds, a 'huh' and a wiggle (it's not always the same time sometimes it gets a bit farther) and then halt again and reboot.

Turn him off. Hmm.  Check batteries again.  Getting >7v  between + and the other 2 terminals.
Try again. Same rebooting sequence.

Change battery to original set after a charge and seems ok again for about 5 minutes, and then a halt.
Reboot again.

Boots up and I immediately try and put him in high step mode, hit pleo button - halt.
I check battery again still >7. 

Can I buy a clue?  Is this likely battery issue or internal issues?
I would tend to guess battery
1) because the two batteries provide different behaviors
2) One is known to be older than the other
3) they're both 2 yrs+ old.
Recommendations?  Anything I can test further?
I have a cheap multitester.
Is there a testing FAQ somewhere I can reference? 

[I-Net]

For me it seems a bit implausible that suddenly both batteries are defective.

[DragonGirl]

Well I'd been seeing increasing halts but never at this pace before.
It was a halt here or there and I just assumed battery was draining to quick for Dunno
to go to sleep and I'd change batteries.

[I-Net]

Just found this vid

<a href="http://www.youtube.com/watch?v=PJxwZFser2I" target="_blank">http://www.youtube.com/watch?v=PJxwZFser2I</a>

Here the outlet seems to be defective.
Maybe that's your problem, too?
That would explain why suddenly both batteries don't work properly.

edit:

i forgot that you can't see the youtube-comments when i embedd the video here...
so look at the comments at this link http://www.youtube.com/watch?v=PJxwZFser2I

[DragonGirl]

It's not making sense to me.  What state was the battery in? 
He can't say that the battery was full or near discharge. 
It could be it had enough to boot, but not enough to complete boot process.
Could have been insufficient charge near the border of functionality.

In my case it clearly has the voltage.
I can't say it continues to deliver it under load, but I'm not sure if that's
something NiMH batteries do and I can't find any documentation that leds
me to think that.

I understand NiMH can get polarity reversal - but wouldn't I see
-7 volts across the terminals?

Perhaps just one battery in the pack has gone bad...
Could one in the pack discharge quick and cause this?
Could one in a pack discharge dropping overall and then after power removed appear to 'recover'?

I'm going to try two things-
1) Put the battery into the freezer overnight, then remove it and let it come back to room temperature. This 'trick' can apparently help to break up any crystals that form in each cell and so help to revitalise poor performing cells.
2) power cycle the charger and put the other battery in the charger.

If that doesn't work with either then the next things to try are
-discharge one of the packs til it's down to 1v with something (a light bulb?) and then recharge.
-find a new charger (but I really doubt this is the cause).
and the ultimate .... get a new battery and charger.

If after that nothing has improved - then I can't see how it's battery.

[grumpy]

A good fully charges set of batteries should read about 7.2v, weak batteries around 6.8v when fully charged.  If possible, can you get him connected to your computer with DinoMITE?  That way you can check the internal voltage and current.

Keep an eye on the battery when charging to see how long it's taking for the light to turn green.

[InmemoryofRomeo]

If the batteries are two years old then it is possible that they are defective, they don't seem to have a very long shelf life unfortunately.

[alexlloyd54]

when you charge the battery, be sure that it is firmly fixed inside the cradle, you could hear the (3 clicks)

later when you come back and find the (green) light is on, which means the battery is charged, you have to switch OFF the mains, take the battery out, then return it back to the cradle and switch the mains ON, and leave it till it is fully charged and the light become Green.

this way you would be sure that the battery id fully charged.


on the other hand, If your batteries are old, or have not been used for a long time (a year for example), then the possibility that they need to be replaced by new ones.


If you are not going to use your pleo for a long time, then you should charge the batteries and discharge them every once and a while, this scenario applies to all rechargable batteries.

 

[DragonGirl]

What do you mean by 'switch off the mains'?
'switch off the mains' to me means to switc off the power to the house from the main panel.
Could you clarify?

[InmemoryofRomeo]

For you that means just unplug it... (Most countries have switches on the power point to turn it off, except America )

[DragonGirl]

Ah....
I can see putting in a fully charged pack into it would elicit a full discharge/recharge cycle.
Is there something special about power cycling the charger?

[DragonGirl]

Well, one of the batteries just had a charging issue, after the recharge, it's 20 minutes and Dunno
is running fine.  That was the battery with the halting action.
I'm running it now on that til the battery is down all the way to see if it halts again when it's down low.
Might be dropping too fast for the programming to go to sleep kicks in.

In the mean time I'm off to go relearn some Dino-Mite.  I want to hook it up to watch the power
as the battery runs down, that was a great suggestion.

The other battery will wait til later...but I'll report on that as well when I get some time.

[DragonGirl]

Yup, the battery ran down in 33 minutes and I didn't read quick enough to get Dino-mite connected
to get a reading.  But when I restart Dunno, it hangs again in short order.

If I get out my little voltmeter the battery claims 7.4v.

[DragonGirl]

The battery that exhibited reboot is now in.
Dunno immediately went to sleep and been that way now for 28 minutes.
It snuffles and does little barks and shifts sleep positions.
But I can't wake it up.
motors sound buzzy.

DinoMite battery reading after 30 min in this sleepy state is
stats power
                  Battery Voltage = 77, Min 71, Max 80 (tenths of a volt)
              Battery Temperature = 27, Min 24, Max 27 (degrees C)
                  Battery Current = 671, Min 293, Max 3123 (milliamperes)
             Battery sensor value = 79 (% capacity remaining)
      Battery sensor direct value = 79, Min 0, Max 79
              Battery Voltage A/D = 667, Min 539, Max 708
          Battery Temperature A/D = 280, Min 186, Max 352
              Battery Current A/D = 94, Min 41, Max 437
            Thermistor Resistance = 8986, Min 8810, Max 10751 (ohms)
      Battery Internal Resistance = 622, Min 529, Max 622 (milliohms)
        Battery Capacity Consumed = 243 (mAh)
                       Powered up = true
                  RTK Adjustments = 40
                           RTK IK = 8999
                           RTK VB = 24
Power monitor reset early warning = 0 (/LLO)

What are the current requirements?

I could only find this online about current: http://www.botmag.com/articles/02-26-07_Ugobe_Pleo.shtml
CALEB CHUNG:
It really is kind of surreal—you find yourself on the same path as nature. For example, nature has lactic acid to cause our muscles to slow down when they are getting overworked and inefficient. Similarly, when running all the motors in Pleo, the batteries wear out quickly. We had to write “lactic acid” code to limit the current draw and have Pleo change behaviors and take a rest when the motors are being inefficient due to current draw. The effect is what we expected; Pleo looks more natural and conserves power.

I'm also not sure exactly what each entry in the output means.
I know generally, but not specifically, such as A/D usually means analog/digital
but what does Battery Voltage A/D mean relative to Battery Voltage?

[Knud Erik]

Hi
               Battery Voltage = 77, Min 71, Max 80 (tenths of a volt)
              Battery Temperature = 27, Min 24, Max 27 (degrees C)
                  Battery Current = 671, Min 293, Max 3123 (milliamperes)
             Battery sensor value = 79 (% capacity remaining)
      Battery sensor direct value = 79, Min 0, Max 79
              Battery Voltage A/D = 667, Min 539, Max 708
          Battery Temperature A/D = 280, Min 186, Max 352
              Battery Current A/D = 94, Min 41, Max 437
            Thermistor Resistance = 8986, Min 8810, Max 10751 (ohms)
      Battery Internal Resistance = 622, Min 529, Max 622 (milliohms)
        Battery Capacity Consumed = 243 (mAh)
                       Powered up = true
                  RTK Adjustments = 40
                           RTK IK = 8999
                           RTK VB = 24
Power monitor reset early warning = 0 (/LLO)

It looks like the temperature is high and that the internal resistans of the battery is to high

BR Knud Erik

[DragonGirl]

Why do you say that?
Is Min/Max just the values read or some triggered internal numbers.
I couldn't find that anywhere...

[mweed]

The values are the minimum and maximum recorded since pleo was turned on.

[DragonGirl]

I've been doing a little reading and this site was very helpful in learning more about batteries.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/dcex6.html
The short answer is - internal resistance rises as the battery gets older.

So given what I measured does that mean that at 622milliohms as measured by Dino-MITE
is a good indication that it now has so much internal resistance, that the voltage
that the pleo sees now dips well below 7 v.
IE V(pleo)=V(without the external load ie 7.4 or so) - current * internal Resistance << 7
yes?

So I've learned the following - how after a 3 full charge and full use/discharge cycles
both batteries appear to be performing much better.  I can get 30-40 min out of both.
I'm taking notes now on the batteries as i use them.

If I put a mostly discharged battery in, he may start but halt immediately.
It's clear the reboot sequence is somehow related to a particular state of the battery when mostly drained.
I haven't been able to reproduce the reboot sequence tho to verify the state of the battery.

It's still not clear how to tell what state I'm in from the printout.
Even when it's doing a shutdown the printout didn't make it clear to me why it went down, but after I tried a manual reboot on the battery
and it clearly halted in boot, I knew it was battery.

FYI - When it shutdown it printed out  diagnostics for power (copied here) and sensor  - very interesting if not completely illuminating.

>>
POWERING DOWN!

                  Battery Voltage = 77, Min 71, Max 84 (tenths of a volt)
              Battery Temperature = 54, Min 33, Max 57 (degrees C)
                  Battery Current = 364, Min 328, Max 3931 (milliamperes)
             Battery sensor value = 79 (% capacity remaining)
      Battery sensor direct value = 79, Min 0, Max 79
              Battery Voltage A/D = 685, Min 531, Max 742
          Battery Temperature A/D = 112, Min 15, Max 252
              Battery Current A/D = 51, Min 46, Max 550
            Thermistor Resistance = 3099, Min 2614, Max 7384 (ohms)
      Battery Internal Resistance = 522, Min 356, Max 522 (milliohms)
        Battery Capacity Consumed = 966 (mAh)
                       Powered up = true
                  RTK Adjustments = 175
                           RTK IK = 7123
                           RTK VB = 24


Still curious on how to read this.  All clues welcome.