Battery problem solution a discovery?

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rovioMan
rovioMan's picture

 

chris75 said: 

Symbol on PCB board shows one orientation and the diode component (D4) is soldered the opposite direction.

I took a picture of it to show the problem:

I removed the diode tested it was ok (it was) and soldered it back the right way. 

Things looks a lot better, i placed Rovio on dock and it full charged and kept battery charge for 2+ hours (7.05V) , moving the Rovio looks like it's on steroid now.

just thought i would share that i just received my Rovio the other day from thinkgeek.com and this diode is no longer on the board?!?!?!?! My Rovio however experiences the same problems(it will not fully charges, i have to repeatedly remove it then put it back on the dock because it stops charging and says "Roaming", while still on the dock, before being fully charged) Could this diode be the problem to the Rovio charging/ dock problem? I am waiting to hear back from customer support.

Photobucket

 

chris75
chris75's picture

From what I remember this missing diode is really doing something.
I think it routes either battery pack power or dock power to the main power line.

So if it's missing sensing logic may be confused by levels on power line.

Any medium power diode like a 1N4004 should do the trick.

So if you have this kind of diode (found in dead power adapter for ex ) and a solder gun, you can try to put one in place.

Hope this helps.
Chris.

rovioMan
rovioMan's picture

Well I do have access to a diode and I can solder, so the question is do I try and fix the problem myself or wait a few days to hear back from customer support? Just to confirm the missing diode should be facing same direction as one next to it, right?

rovioMan
rovioMan's picture

Just took a closer look at the board and it appears that wowee removed the diode and replaced it with a jumper on the bottom.

chris75
chris75's picture

Interesting,
FYI, I also found the raw voltage from dock looks too low for the IC managing the charge.
From the (weak) 8V adapter to transistor controlling charge the voltage drop is quite big, (diodes / bad dock contacts). Fully charged pack would probably be around 7.2V and for sure the Rovio power board can't reach this level.
So in my case, besides fixing the diode orientation. I switched to a 9V adapter and also replaced the battery pack (original one died after a few cycles).

Hope this helps.
Chris

liang
liang's picture

hi,
after a lot of experimenting and after i fried two batteries i gave up,
but then i recieved e-mail from this forum, people are still trying , so i orderd a new battery and started again. same problems. then i started looking at the mechanics of the dock and found that one of the contacts which moves when the rovio docks was stuck because the opening in which it was supposed to move up en down was too narrow so it did not connect al the time. I made the opening larger, and now my rovio is charging ( already for half an hour ) without truning off or trying to leave the dock on search of the dock.If this continues i will post a film or foto;s of what i did.

wolfmanjm
wolfmanjm's picture

I started playing with my Rovio after about a year. I had bought a http://www.amazon.com/Prophet-Plus-AC-Peak-Charger/dp/B0006N6XWK Prophet charger for the batteries to get around the problems, I even built a new battery pack using 3300maH cells.

So I know they are fully charged, and the factory batteries seem to work fine for a while, however my higher capacity cells don't last very long.

I noticed that the Rovio shuts down saying battery is low way to early... when I remove the battery it is still at 6v, which is the nominal voltage for 5 (1.2v) cells. after charging both packs are at around 7v.

At 6v there is still plenty of charge left, so is there a way to adjust the shutoff voltage on the Rovio? seems it is way too sensitive at the moment.

Raz
Raz's picture

I recently got a Rovio from Amazon and the diode in question is missing from the board. It is obvious that the diode was there initially, but it was then removed. This must be a factory fix on newer models, so I guess the diode is not needed anyway.

Raz

Raz
Raz's picture

My new Rovio (purchased in June from Amazon) does not have the diode in question at all. It was there when the board was manufactured but it was obviously removed before the unit was sold. The Rovio works fine, battery life is about 2 hours and takes about 1 hour to charge.

Raz

kraiwut
kraiwut's picture

I thought I got the solution for my battery problem when I saw Chirs's post about incorrect direction of diode, but after I open my Rivio, I found that the diode on my Rovio's charging circuit is correct. However, I still have the issue as describe in this thread. Even after I replaced the battery. Now I don't know what to do.

chris75
chris75's picture

So you have new battery and new power adaptor (9V) ?

Even with new battery stock power adapter is too weak to charge when battery is too low.

Symptom, when docked, is blue leds pumping and then shutoff after a few mn.

Is this what you get ?

Chris

Andr0id
Andr0id's picture

OK. Got my Rovio from ThinkGeek couple of days ago. Setup was done via network so no USB computer connection issues. Of course I have the charging issue as everyone else. I looked at the charging board, the D4 diode is not there but a jumper is installed on the underside of the board instead.

I placed two strong magnets on the connection pads of the Rovio to make sure there are no contact issues with the docking station. When docked the lights pulse for about an hour, then stay bright. After a few hours everything goes dark. I can reset power and use it for about 20 min before the bat shows very low.

To eliminate all possibilities suggested so far I am currently charging the batt with my Hobby multi-charger to make sure it has a full charge.

I will respond with the results. If I still have problems then I shall dig a deeper.

ThinkGeek gave fair warning their might be issues and agreed to accept any returns no questions asked so I was/am willing to give this a go as best I can as when working this thing is great. www.nmscientific.com/andr0id.com

kraiwut
kraiwut's picture

Yes, the symptom is that the blue LEDs blinking and then turn off after a few minutes when I put put the Rovio in the dock. I also used an external charger to charge the battery, which helps the first few time, but after that, Rovio stop charging the battery again.
And yes, I have both new battery pack and new 9V power adapter.

chris75
chris75's picture

Looks bad, on my Rovio I also opened the dock and replaced 2 wires going to the retractable pods (below the springs ..).
For some reason there was a significant voltage drop between input 8/9V plug and what Rovio gets on dock.
I also cleaned the mechanical contacts especially the one inside docs that cut/short power when power pods are moved up/down.

My experience is the Rovio charger board needs >8V or it will fail to pump enough current to get the battery voltage go up quickly and then the Rovio MCU will shut off the Rovio on low voltage condition.

Chris

Andr0id
Andr0id's picture

Update: Fully charged batt. Rovio worked good. used for about 15 min, still showed full batt. Sent to home and it docked with no issues and even showed charging for a bit. Let it sit there overnight. Next morning, no lights. I power cycled it and i went from 100% to 80, then 60 within just a couple min. This seems to indicate to me that either it was not charging on the dock at all or that the dock was actually draining the batt to some extent. I pulled the batt and put it back on my imax charger and it is charging as if it was dead. So my next step is to take a closer look at the base. I will keep this updated.

Andr0id
Andr0id's picture

Ok, docking station looks sound. Input power is parallel between both the board and directly to the contact pins that go to the Rovio when docked. No mechanical issues and i can read a solid 8.27 V at the pins. The power adapter "says" it is 8V and 2.5 Amps so that should work fine.

Now the interesting bit. IF the Rovio is physcially off but docked, should the batt still charge? If i have the batt pulled and a meter in its place and dock the Rovio i get 5.7V to the batt connector. This obviously is too low to charge a 6 V batt. Is this a normal condition because the Rovio is off or does this sound abnormal to you guys?

chris75
chris75's picture

No the Rovio daesn't charge if docked with switch off (at least mine:).
If i remember correctly when looking at charging sequence with a scope the MCU (Board controlling motors /LEDs / encoders etc...) shut off the charger controller (few wires going from MCU to charger board) .
When MCU is off , charger board is off too. You are probably measuring leaking voltage.

I reversed engineered a bit what the wires do, need to get back my notes and share probably.

Chris

chris75
chris75's picture

From my notes.
Charger board built around a LS2516, got no datasheet but seem to be a "standard" NIMH charger microcontroller.
Charge board works on it's own, ie as soon as it is docked, it will charge depending on battery level sensed. It will stop when senses "delta peak" / max voltage ie: Voltage drops a bit at end of charge.
Charge board / MCU connected via 3 wired (+ground) :
CS: Voltage to indicate to MCU charging level (sensed by Rovio to blink blue LEDs /slow/fast/solid)
CPS: To detect when docked , sensed by MCU too.
CPC: Not sure but looks like this one disables charger if MCU not up (Rovio off). Looks like a wire for MCU to switch off charger.

Flaws I think I found:
* Docked / charging: Rovio takes lot of power and input voltag is varying fast (noise), it perturbates battery voltage during charge phase. Charger chip is probably lost trying to detect end of charge. Should have been wiser to power Rovio directly from dock and isolate battery for charging when docked. Either the design is flawed or some component is not doing its job.
* Charger board power: Dock power goes to a first diode (probably prevent inversion of voltage) then some control transistors then a self then diode again
etc.. finally lots of voltage drops and charge chip has not enough voltage margin to operate. This is probably why using 9V adapter fixes issue for some people.

Hope this helps
Chris

Andr0id
Andr0id's picture

Thanks for the info. Yes I notice a few things. I fully charged batt. Put Rovio on the dock and it still charged a bit, max 7.08 Volts then drop to 6.92 when it "thinks" its charged. Within 10min drop to 6.63V, next 10min drop to 6.52, at this point the web interface sent a warning to return to dock for charging. (although it was already on the dock) however, the batt level indicator still showed full and the lights were still solid. I picked it up and redocked just for fun. It started to charge again. Eventually it reaches what it thinks is full charge and then stops.

The issues I see is that like you said, it runs off the batt all the time, and even if I KNOW it is fully charged it still runs off the batt. When it "thinks" it needs to charge it lets you know; however, it does not in fact do anything about it UNLESS it is re-docked. The result is.... if Rovio is on the dock and even successfully charges, it will run the batt down eventually and not recharge unless you physically re-dock.

Problems I see:

As stated.

1. I think the Delta is off and it is reporting low even when it is not.
2. Rovio will not charge unless you tell it to, so unless you watch it every 2 hours it will eventually die and you will have to cycle power to get things going again.
3. As stated, the batt should be isolated when docked and the Rovio run off of the power of the dock, NOT the batt. (I have noted, the Rovio will not run off of the dock if the batt is not installed currently)
4. As stated by Chris, the charging board itself is in question as to if it works as expected or not. Some have diodes, some have jumpers, either way, it seems the charging is not even 80% true.

Solutions:

1. My first attempt is going to be the easiest, that is go to a 9V supply with the attempts that the charging board will work better. As Chris stated though, since Rovio runs off the batt and it is noisy I have doubts that the board can sense a full charge with any accuracy.

2. Attempt to isolate the batt when docked. This will take a little thinking and perhaps I might have to throw in some extra logic here and a picaxe to boot.

3. If all else fails combine step 2 with a home grown charger.

4: optional (again using a pic controller 'fake' some of the signals to the MCU so as to be more accurate.

Best bet is step 2 and that is what I will think hardest on. Thanks for the added input Chris! (I WILL make this @%^#%@ think work!)

Andr0id
Andr0id's picture

Battery problem for the Rovio Solved.

The answer was to isolate the bat when docked. This required a second power supply to power the MCU when the Rovio was docked. 6.24V seems to be the best voltage. A 5V 1Amp supply would not keep the MCU going.

So I modified the Rovio with a micro switch under it that when normally closed powers the MCU via the bat, when docked the contacts connect to the Rovio as normal but a power lead is also pushed up into the Rovio activating the micro switch and providing power at the same time, thus powering the MCU from the second supply attached to the Dock. So far this seems to be working. as the grounds are tied together on both supplied it is able to sense when the bat is charged and it turns the charger board off yet stays powered via the second supply instead of the bat. When Rovio leaves the dock the micro switch is released and power returns to the MCU from the bat. The only think i might still do is add some caps to keep the charge long enough between the switching of the supplies so the Rovio does not reset as sometimes it does now. We are only talking a second or less but that is enough. A refresh of web page grabs the Rovio again though so no loss of remote control.

Now I can play with it and it charges.. weeee!

chris75
chris75's picture

Excellent,
so this could be probably integrated to Rovio using a relay + caps and curring a few wires inside.

I started designing a replacement charger board with a PIC (to do also more stuff like power off / up on timer dock etc..), your fix is definitively simpler :)

Good work!
Chris

vinnie
vinnie's picture

Thanks for posting your Andr0id!

Do you have any pictures to show how the switch works? Also pics of the charger and the Rovio modifications would be great!

danBet
danBet's picture

chris75 said: Found possible cause ?  while reverse enginnering the Battery charger board and building a replacement, I found a diode was apparently soldered the wrong way. Symbol on PCB board shows one orientation and the diode component (D4) is soldered the opposite direction. I took a picture of it to show the problem: I removed the diode tested it was ok (it was) and soldered it back the right way.  Things looks a lot better, i placed Rovio on dock and it full charged and kept battery charge for 2+ hours (7.05V) , moving the Rovio looks like it's on steroid now. Prior to this I replaced weak 8V  adaptor by a powerfull 9V one and replaced NIMH pack by a good 4600mAh  one,it improved things but did not fix the issues. I still experienced disappointing autonomy/chaage  (<45mn off dock) and constant charging / discharging (blue leds blinking) cycles with most of times automatic shutoff as battery went too low. All in all Rovio was unable to survive more than a day without shutting off and requiring the dock/undock trick to kick charge cycle again.  If anybody had similar symptoms and knows how to dismantle the beast, i'm interested to know if D4 is wired like mine or not. I'm still doing tests to see what's the new Rovio MTBF :)  Hope this helps.

Hi Chris,

I was wondering if you are willing to repair my Rovio or advise me where I could sent it to have it repaired with your solution.  I'm not an elecctronic savy guy and I'm pretty sure I would damage mine if I ever try to solder off anything.  I'd love to have my Rovio usefull again, but I don't seem to find any support or repairs for it.  I would gladly pay you for your time and service, if you would repair mine.  You can contact me at dbetanc@mac.com

Thanks!

Daniel

chris75
chris75's picture

Daniel,
first if still possible, try to get replacement one from vendor.
Otherwise you may find local geek club or hackerspace with people
who can help, this kind of toy raises interest of the guys with solder guns ...

I would be glad to help, but shipping cost is probably much higher than getting
a new one, and I'm far from being certain I could fix yours.

Chris

rovio fan
rovio fan's picture

can ya post the fixed charger board pic so i can see if mine need changing?

JFR
JFR's picture

ANDR0id, your the man, you figured it out.

Wow, Can you post the picture of the mod.
I always guessed the reason for the battery not charging full, was the cpu, was still drawing current, while trying to charge the battery also.
Yep, power the cpu(mother board) part of Rovio by itself , and the battery by another source.
JFR

rovio fan
rovio fan's picture

ok doing the d4 mod droped the volts to 2.50v while on the charger with it turned on and 2.15v turned off not shur if thats right?
the one next to it reads 6v on the charger turned off and 8v oon the charger with it turnd on but wont charge. did i do something wrong???

sonyjoseph
sonyjoseph's picture

ok like cris75 said ,because of the poor battery life of my rovi i opened and see.the diode was fitted like inverted.let me change its position ? do you think does it burn the circuit?

jlee
jlee's picture

Hi chris75,

I checked my Rovio, found the D4 diode already removed and they welded the 2 point that original used by D4 diode.
Do you think I should buy a diode to solder on D4?

Thanks a lot!

chris75
chris75's picture

Hi Jlee,
I don't have schematic so not sure what this diode is for, anyway if your Rovio daesn't charge well you should firt check battery quality , Rovio one is very poor and many reported one element at least was below specs in term of voltage.
Also power supply is a bit weak so others (like me) replaced by a 9V (I replaced battery too).

If after all this this is still not acceptable , adding a diode instead of the short circuit may be something to try, don't think it do harm as mine is setup like this. I suspect the guys at Rovio have schematics and decided no diode was better but they could be wrong :)

Hope this helps.
Chris

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