BuWizz - High Performance LEGO Power Functions Controller and Battery

[WW Bricks Studio]

11 minutes ago, Toastie said:

I believe the BW team can easily clear this up and should do so. However, @Zerobricks repeatedly stated here, that such issues are taken care of by BW tech support. Did any of you tried to contacting them directly? And if so, do you mid to share the reply from BW support?

Lets think a bit about LiPos and chemistry ...
 

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There are numerous electronic devices (chippies) which are used, when it comes to LiPos. Some companies go crazy on that because they are operating world-wide, as TLG does, and fear lawsuits or even harm to people + lawsuits and that can go easily out of hand. Others are more lax on such issues - Chinese companies sometimes (and only sometimes and for sure >not< always) - and integrate less safety measures into their devices. Today, almost all cell phones run on LiPos as power source. Yes, in the beginning there were issues with the LiPos "going off", also with some serious injuries as a result. That has become much, much better: Simply judged by the gigantic number of cell phones in use, blow-ups have become negligible in numbers, that is. For one, LiPos have drastically improved regarding their internal "structure" as well as the chemicals employed. After all, a LiPo is nothing more than a chemical system pushed to one side of the equation(s) upon charging, far out of equilibrium and relaxing towards equilibrium when discharged. A good number of things can go wrong here, as you want the cycles of charging and discharging approaching infinity. Well Entropy is hard, very hard (as in impossible) to beat and over a couple of thousands of cycles, Entropy wins. Always. All we can do is expand the number of cycles, but Entropy still patiently waits (with the chemical equivalent of a scythe in its hands ;).

One of the worst things one can do to an electrochemical system such as a LiPo is: Stressing it beyond reasonable currents. Current means: Number of parallel/consecutive chemical reaction steps per time. Each electron flown through a motor was the result of an oxidation/reduction reaction. The more electrons you want, the faster this chemistry has to proceed. Released "heat" is then generally a good measure of the extent of reactions taking place per time. LiPo discharging is a process thermodynamically described as exergonic - it proceeds spontaneously and with release of previously bound chemically stored energy. One results is the flow of electrons, the other is release of heat.

When discharged slowly, all is good = cell phone. When discharged rapidly = 2 WB motors one needs to carefully monitor several things; and now the electronics kicks in: Maybe BW does monitors the LiPo's temperature. When too hot: >OFF< and wait (days) as safety measure. Maybe BW does monitor max current. When that exceeds the max. stated LiPo current: OFF. It could also be that the electronics itself is protected - in this case "resettable" fuses may be used - they sometimes require time to recover (by entirely removing power - the BW LiPo is always connected to the circuitry, as there is no physical switch entirely electrially isolating the LiPo from the electronics - otherwise the nifty on/off push buttons simply can't work). BTW, the LEGO LiPo has many of these features as well - you can send that to heaven by charging it with +20V - it descends from there after having fully but very carefully discharged the LiPo - takes a few days though. During that time, it plays dead, but it isn't.

 

I believe it is rather straight forward for BW to tell people here (or via their tech support), what is going on here. Or maybe folks who contacted them and got an answer can post their reply here.

Electronics either dies or not. It may play dead, but that does not count as dead.

All the best!
Thorsten

 

   

I have wrote the email to the support team on 10/15, their reply is as below:

1. control the motors more gently or use the ramp functions to soften the motor control.

2. try to reinforce the steering mechanism. The new update will allow you to limit the power.

It requires a couple of weeks for the new update. 

So, keep waiting and be faithful.

[Toastie]

2 minutes ago, HectorMB said:

the info you quoted is quite clear :)

Thank you! I didn't quote it though, I just wrote it - I don't want to get anyone in trouble but me!!!

(I am currently reading 13 dissertations up for a price at my university - man. I am chemist and they go over all faculties - what do I know, I just work here. Well, 11 more to go, deadline is tomorrow. So need to do something else in between liters of coffee ...)

Cross my fingers that it works out for you!

Best
Thorsten 

[HectorMB]

Well, I think that's a good response. I mean, makes sense from my point of view. 

 

Hoping to see that update! :)

[HectorMB]

1 hour ago, Toastie said:

Thank you! I didn't quote it though, I just wrote it - I don't want to get anyone in trouble but me!!!

(I am currently reading 13 dissertations up for a price at my university - man. I am chemist and they go over all faculties - what do I know, I just work here. Well, 11 more to go, deadline is tomorrow. So need to do something else in between liters of coffee ...)

Cross my fingers that it works out for you!

Best
Thorsten 

Sorry my confusion! But anyway, is even better if you wrote it and you know what you're talking about :). Me, I just know the basics and I just read what others with more experience show. 

Edited November 8, 2021 by HectorMB

[amatros]

6 hours ago, HectorMB said:

WOW. No, i didn't yet. Nevertheless, given that both of you guys, @WW Bricks Studio and @amatros, experience the same issue I am a little bit afraid. One of the major aims of the BW3 was to be able to cope with two BW motors, but it seems not only that the maximal output of the motos cannot be reached but also that the unit completly dies, no?

None of you were finally able to recover the BW3 from dead?

PS: Although it scares me, I will try, as in such case it is something that should not happen and seems to be a serious issue (I bough 2 BW motors just to mount them in a BW3). 

Not yet. I am waiting for it to discharge as was suggested by somebody here. I’ll wait for a few more days and will try to connect it to power. As of now the BW still does not respond when pressing the on/off button. 

[Danil]

please explain! How can you control a model with bouiz, buggy motors and electric control plus using a gamepad? a huge amount of information and even more opinions! please give examples. Thanks in advance for those who responded!

[Igor1]

@Danil For me an acceptable option to use the gamepad is through the BrickController2 app, which recently added support BuWizz 3.0. So now you can use PU electrics with buggy or BuWizz motor. Or you can connect the buggy motor to BuWizz 2.0 and use PU electrics at the same time via the Technic Control+ Hub.

 

Edited November 14, 2021 by Igor1

[WW Bricks Studio]

Hi, all 

Here to share my 42083 BuWizz 3 + BW Buggy motor + PU L motor video controlled by BrickController2 App.

 

[Danil]

I was interested in the following aspect regarding the Buwizz 3.0 battery - the manufacturer's website states that the battery capacity is 2300mA / h and that the battery is replaceable. on the Sariel video, when parsing, it is clearly visible that the HPL 502852-5C-381P element is used at 11.1V 800mA / h 8.88Wh-where is the truth? and second, if the battery is replaceable, what batteries and with what characteristics can be used in this device? It would also be interesting to know whether the battery charge controller is built into the bank or is it soldered on the motherboard? Thank you in advance for your feedback!

Edited November 24, 2021 by Danil

[madn3ss795]

5 hours ago, Danil said:

, it is clearly visible that the HPL 502852-5C-381P element is used at 11.1V 800mA / h 8.88Wh-where is the truth?

Both are correct. It's a ~8.8Wh battery. (Wh)*1000/(V) =(mAh).

At 11.1V (which I assume is the maximum discharge voltage), it's 792 mAh.

At 3.7V, it's 2378 mAh. This provides an easy comparison point against phones, laptops and other small electronic devices which also use 3.7V for showing their capacity.

[m2fel]

Still does not make sense. The battery in the picture reads 880mAh and on the buwizz page it is 2300mAh.

You also need to be more careful with units. mAh*V=mWh

 

Why buwizz does the calculation with 3.7V (the value of one lipo cell) is strange to me. General the actual voltage of the battery is used like in the picture: 800mAh*11.1V=8.88Wh=8880mWh

And I assume buwizz uses a 3s lipo battery at 11.1V

Edited November 24, 2021 by m2fel

[Igor1]

Now I've specially opened my BuWizz 2.0 to take this photo. As you can see, there are two glued silver cells, the top one of which has 3.7V, 1900mAh, 7.03Wh. I'm not sure if these values are for both cells or for two at once. The bottom cell is very tightly glued to the top one, so I don't know what is written on it.

Edited November 24, 2021 by Igor1

[m2fel]

That's interesting. And proves I was wrong as they use a 1s battery :)

the blue battery is 3s1p which means three 3.7v cells which sum up to 11.1v (series connection) the silver battery has two 1s cell in parallel connection (1s2p) which ads up the capacity of the cell but the voltage stays 3.7V. Thus they need a step up converter for higher voltages.

Bit if the blue battery is from a buwizz 3 this is a 3s lipo and on the homepage the data implies a 1s lipo. I am confused.

Would like to have someone else to look at this as I only rushed through the data :/

[Toastie]

2 hours ago, m2fel said:

Why buwizz does the calculation with 3.7V (the value of one lipo cell) is strange to me

2300 > 880. Sounds better 

1 hour ago, Igor1 said:

Now I've specially opened my BuWizz 2.0 to take this photo.

These are actually two cells, each rated 1900 mAh. right?

Best,
Thorsten

[HectorMB]

Well.. i have very little idea about electronics. But what I can say is that the BW3 delivers a sh*t out of power... although you have to recharge it quite often. 

In my recent set ups, after 20-30 min playing with it (3 PU L motors and 1 L PF motor) the battery is dead. Nevertheless, I am quite hapy with the performance and the customer service. Now is just to wait and hope that the issues with the steering is solved and that we got implemented the features for PU motors (it is a need to efficiently manage gearboxes, among others...)

[Toastie]

1 minute ago, m2fel said:

Would like to have someone else to look at this as I only rushed through the data

There is even more confusion - in this very thread around June/July 2021 there was some discussion on max. vs sustained power delivery etc. pp. I guess at that point, the discussion was mingling electronics and battery data. After all, there is certainly a) no outer space battery technology in the BuWizz (when you do not consider Chinese LiPo manufacturers as located in outer space ;) and b) I guess it is always a bit confusing. They also claim on their website that their rechargeable battery is of the type Li Ion, oh well, chemistry sucks. However, the data printed on the LiPos is what counts.

What happens when you put them in parallel or in series or charge them etc. is nicely covered here, but you guys may have all read that already:

https://rogershobbycenter.com/lipoguide

Best
Thorsten

[m2fel]

@Toastie u need to look at the c rating printed on the battery. Yours  has 5c and 1900mAh which means it can provide 5*1900mA = 9.5A max.

The blue on is also 5c but at 880mAh which means 4.4A max.

Most probably the limiting factor are the other electronics in the buwizz to make sure not to fry our toys

Edited November 24, 2021 by m2fel

[Toastie]

22 minutes ago, m2fel said:

no, should be two cells with 950mAh each.

Hehee yes, it is confusing. I am working on it - here is a crystal clear explanation of the gibberish on the cells form this website:

https://www.fedcobatteries.com/design/cell-configurations

For example, if a higher voltage is desired, cells are assembled in series and if a higher current capacity is desired, cells are assembled in parallel.   

• Series batteries have the negative (-) terminal of the 1st cell connected to the positive (+) terminal of the next cell in the string.  The battery voltage is the cell voltage multiplied by the number of cells in the string, while the capacity remains the same.  
• Parallel batteries have both (+) terminals and both (-) terminals of each cell connected together.  The battery voltage equals the cell voltage, but the capacity is the cell capacity multiplied by the number of cells in parallel.  Cells in parallel should be matched for best performance, while lithium primary cells in parallel must have blocking diodes for safety reasons and lithium-ion cells must be matched for safety reasons. 
• Series-Parallel  batteries have identical string sets of series cells assembled in parallel at the (+) and (-) terminal ends, but the interior cell connections are normally not connected to each other.   The battery voltage equals the voltage of the strings and the capacity equals the cell capacity multiplied by the number of strings.

There are accepted industry abbreviations for these configurations.   Examples:

• 1S1P = A single cell battery.  V = Vc and  Ah = Ahc
• 1S2P = A battery with 1 cell in series and 2 cells in parallel.  V = Vc x 1 and  Ah = Ahc x 2
• 2S1P = A battery with 2 cells in series and 1 cell in parallel.  V = Vc x 2 and  Ah = Ahc x 1.
• 2S2P = A battery with 2 cells in series and 2 cells in parallel. V = Vc x 2 and  Ah = Ahc x 2.

So the BuWizz 2.0 has cells in a 1S2P configuration?! Oh my.

 

Wait, wait - the S means "Sets of cells" in series and not simply "cell". So 1S2P = 1set of cells in parallel configuration = 3.7 V with 2x 900 mAh = 1800 mAh. At least then the nomenclature would make sense.

For the BuWizz 3 we have 3S1P = 3x3.7 V = 11.1V @ 880 mAh.

Oh my. At least Thermodynamics is still good here ;)

Best,
Thorsten

Edited November 24, 2021 by Toastie

[m2fel]

@Toastie ur right. But they way it is written on the buwizz homepage it looks like a 1s configuration as they use 3.7V for their calculation. 2300mAh *3.7V = 8.5Wh not a 3s config as seen on the blue battery...

 

Trying to quote I accidentally deleted parts of my last post with the two cells at 3.7V and 950mAh. This is annoying. Sorry

[Igor1]

2 hours ago, m2fel said:

the blue battery is 3s1p which means three 3.7v cells which sum up to 11.1v (series connection) the silver battery has two 1s cell in parallel connection (1s2p) which ads up the capacity of the cell but the voltage stays 3.7V. Thus they need a step up converter for higher voltages.

I think you are right, that is why BuWizz 3.0 doesn't have different speed modes as BuWizz 2.0. It's only a little strange that the BuWizz website says "Battery capacity: 7.5 Wh", while on the BuWizz 2.0 battery itself we see only "7.03 Wh".

Edited November 24, 2021 by Igor1

[Danil]

marketing, such marketing ... the whole world has slipped into this (the word can only be pronounced in Russian)! I have nothing against buwizz, but now I will be careful and very careful, since the first step of a vague description of the product for the sake of marketing and the pursuit of numbers has unfortunately been made, it is not clear what to expect after manipulating the numbers in the description.

[BrickTronic]

6 hours ago, Toastie said:

..

So the BuWizz 2.0 has cells in a 1S2P configuration?! Oh my.

..

For the BuWizz 3 we have 3S1P = 3x3.7 V = 11.1V @ 880 mAh.

..

@Zerobricks

can you confirm :

BuWizz2 : 1S2P  3,7V 2x 950mAh (7,03Wh / 3,7V / 2 cells)          Driver 4x DRV8833 = 4x 1A

BuWizz3 : 3s1P 11,1V 3x 800mAh (8,88Wh / 3,7V / 3 cells)          Driver 4x ?              = 4x 2A + 2x 4A

and how is handled balancing at charging / discharging ?

For charging you still need an Step-Up Converter/Charger, right ?

Can you give here some hints ?

 

Output-Current has increased from 1A to 2A / 4A

What Driver are you using for the 2A/4A ?

 

Jo

Edited November 24, 2021 by BrickTronic

[m2fel]

@Danil there is nothing wrong with the buwizz 3. The numbers are correct and there is nothing wrong with how it is described. I would rate the data for the battery as expert knowledge. Most people don't wanna know how it works but here u can look it up if you know how to read it.

The data for the buwizz 2 on the homepage (indicates a 2000mAh battery) does not 100% match the actual battery (1900mAh) but for the user it hardly makes any difference and maybe they changed the supplier and the page wasn't updated. But also nothing to worry.

 

@BrickTronic u can't just add up the capacity for the buwizz 3 only because there are three cells. At 11.1V it can deliver 880mA in one hour this 880mAh. To triple the capacity you would have to go from 3s1p to 1p3s. Then it could deliver 3*880mA in one hour at 3.7V.

Charging of lipo and li Ion batteries is, if there is more than one cell, done with a balancer which is connected to each cell and checks the load (current) of each cell while charging. If one cell receives to much load it is broken. Also there is a special 'charging curve' which needs to be followed. The is done by a charger and the whole electrics for this is inside the buwizz.

[aFrInaTi0n]

I am curious, is there any known way for giving Feature-Requests to BuWizz Team? Just messaging them via mail and they will reply?

Like having a configurable emergency-switchoff (don't know the excact word used in rc hobbies.. :o) behavior to be set via the app. It would be nice to have a the behavior activateable and additionally having a configureable value for adjust the Timeout in Milliseconds for your own needs.

Background: Recently I got one BT disconnect which led my model run with the last applied throttle straight into a wall leading to some damage. :(

 

[Zerobricks]

On 11/24/2021 at 6:38 PM, BrickTronic said:

@Zerobricks

can you confirm :

BuWizz2 : 1S2P  3,7V 2x 950mAh (7,03Wh / 3,7V / 2 cells)          Driver 4x DRV8833 = 4x 1A

BuWizz3 : 3s1P 11,1V 3x 800mAh (8,88Wh / 3,7V / 3 cells)          Driver 4x ?              = 4x 2A + 2x 4A

and how is handled balancing at charging / discharging ?

For charging you still need an Step-Up Converter/Charger, right ?

Can you give here some hints ?

 

Output-Current has increased from 1A to 2A / 4A

What Driver are you using for the 2A/4A ?

 

Jo

Unfortunately I don't know the exact drivers, you can try writing an E-mail.

5 hours ago, aFrInaTi0n said:

I am curious, is there any known way for giving Feature-Requests to BuWizz Team? Just messaging them via mail and they will reply?

Like having a configurable emergency-switchoff (don't know the excact word used in rc hobbies.. :o) behavior to be set via the app. It would be nice to have a the behavior activateable and additionally having a configureable value for adjust the Timeout in Milliseconds for your own needs.

Background: Recently I got one BT disconnect which led my model run with the last applied throttle straight into a wall leading to some damage. :(

 

I already had an idea for this feature so you can select what happens after you loose connection and how long is timeout. This way you can keep all motors running, brake, coast, etc for a given timeout. Would be very useful for preventing crashes or simply to keep running trains after you lost connection. But there's only so much a small team can do at once.

Edited November 25, 2021 by Zerobricks