Maximizing integrated use of the Powered Up Hub

[Desvejk]

I'm exploring splitting the Powered Up Hub into parts.

The controller board and the battery.

I want to use a small profile rechargeable 9V battery to allow me to fit the Powered UP controller into a smaller Lego build.

Early testing looks promising

Can this work?

Any ideas.

 

VIDEO:

https://flic.kr/p/2mPutgt

 

 

 

 

[Lok24]

2 minutes ago, Desvejk said:

Can this work?

Any ideas.

Sure, as your photos show. Nice work.

You cold use other batteries like rechargeble Lipos and so on too.

[Desvejk]

Thanks. 
My plan is to make an enclosure for the controller board and place the rechargeable 9 volt battery separately.  

[Lok24]

Yes, then, you just remove the two contacs from board.

[legotownlinz]

Sure it works. The board doesn't care where the power comes from as long as the voltage is the same.

One thing that may need to be considered is the overcurrent protection of the board. It has been designed for AAA batteries, so it might draw more current than allowed by the spec of the 9V battery.

[Lok24]

2 minutes ago, legotownlinz said:

One thing that may need to be considered is the overcurrent protection of the board. It has been designed for AAA batteries, so it might draw more current than allowed by the spec of the 9V battery.

I think no, the max. current depends on the chips used, no matter where the 9V comes from, as you wrote.

If they only alow 800mA i.E. it doesn't matter if your power supply could deliver 3A

[legotownlinz]

3 minutes ago, Lok24 said:

I think no, the max. current depends on the chips used, no matter where the 9V comes from, as you wrote.

If they only alow 800mA i.E. it doesn't matter if your power supply could deliver 3A

Sure, but if the battery can only handle 500 mA and the overcurrent protection limits the current to 800 mA, then the battery could get damaged, or even worse, melt down, catch fire, ...

[Lok24]

I see, otherway round. Good advise.

[Phil B]

2 hours ago, legotownlinz said:

Sure, but if the battery can only handle 500 mA and the overcurrent protection limits the current to 800 mA, then the battery could get damaged, or even worse, melt down, catch fire, ...

I am not an Electrical Engineer, but I don't think that's how it works. Your battery dictates how much current is provided to the circuit. So if your battery does 500mA, the controller board gets 500mA and the 800mA overcurrent protection limit would never kick in. There would be no damage to the battery. If a motor wants more current, it will not get it and will stop prematurely or turn slower than expected.

[dr_spock]

Nice.  That's one way to shrink down the size of the PU hub.  It has been a while since I took apart my PU hub,  I believe the two metal contact tabs can be desoldered.  Then a 9V battery connector can be soldered in its place.  It seems easy enough to design and 3D print an enclosure for it.  You can get fancy and add studs and/or Technic pin holes.  Or keep the white top part and make a new bottom piece. 

 

[legotownlinz]

2 hours ago, Phil B said:

I am not an Electrical Engineer, but I don't think that's how it works. Your battery dictates how much current is provided to the circuit. So if your battery does 500mA, the controller board gets 500mA and the 800mA overcurrent protection limit would never kick in. There would be no damage to the battery. If a motor wants more current, it will not get it and will stop prematurely or turn slower than expected.

No, it's this way: The battery does 10 A and then it explodes. All batteries can provide much higher currents than the limit of safe operation. 

A battery back like the one shown in the images above should have internal protection. But it is from China, so you never know if it is really safe.

[Toastie]

6 hours ago, dr_spock said:

Or keep the white top part and make a new bottom piece.

That's what I do. The gray "very" bottom part comes in handy here. And then I use 8878 (purchased a couple back then, when the world was spinning the other way around) fed by power pickups (= modified 9V train motors) from permanently 15 VDC powered "9V tracks" to power the PUp hubs. Works since PUp exists and much longer for PF controlled trains. 8878 has all the bells and whistles on board.

With regard to explosions: It is not as common as suggested. LiPo's usually simply die, when treated badly. The explosions do happen, but whenever that is the case, it is reported on world-wide channels, and amplified upon re-whatever-ing. Nevertheless, be careful with unprotected LiPos.

Best,
Thorsten 

   

[Desvejk]

Thanks for your comments. 
I usually only run trains for short periods and I’d be confident that there are minimal safety issues. 
I’m planning to use this mod in the Lego light rail from City Main Square 60271. 

[dr_spock]

It looks like you're using 9V Li-Ion batteries that have a built-in USB charger.  There should be a battery management/protection module already inside.

I haven't had a Li-PO battery exploded before but I did have one that expanded and cracked the action camera case in half.  It was a good little camera that can fit inside a 6 wide LEGO train.  :-(

 

 

[Desvejk]

I agree. 
I’m  confident the battery will be fine. 
Building the tram now. 

 

[Desvejk]

Finished the circuit board enclosure. 

 

[Desvejk]

Finally finished.

I'm very happy with the result.

Now this tram is crowded with mini figures!

 

VIDEO with the tram running

https://flic.kr/p/2mPQzv3

 

Edited December 10, 2021 by Desvejk

[Toxic43]

Awesome! That is an effective use of space! A tram without a massive section filled with a battery box. Love the 9v tucked in behind the driver, making good use of the space inside the massive moulded piece.

[Desvejk]

Thanks. 
It was quite tricky to fit everything in place. 
Now the mini figs are happy and that’s the important part. 

[Desvejk]

I have now fitted the color and distance sensor so that I can program the tram Ising the Power UP app.

Fitting the sensor brick was easier that I have found for other trains.

All works as I had hoped.

 

[JopieK]

Very nice working tutorial / proof of concept. Will be useful for a lot of other train and other automation applications. I pinned it as it.

[Lok24]

Really good work, thanks for sharing.

[DarioD]

Great, I love DIY solutions, especially when they are very discreet and clean, like yours. :-)

[collectormania]

very interesting DIY. i will try it for my trains, thanks for sharing ;-)

[Roadmonkeytj]

On 12/8/2021 at 5:01 AM, Desvejk said:

I'm exploring splitting the Powered Up Hub into parts.

The controller board and the battery.

I want to use a small profile rechargeable 9V battery to allow me to fit the Powered UP controller into a smaller Lego build.

Early testing looks promising

Can this work?

Any ideas.

 

VIDEO:

https://flic.kr/p/2mPutgt

 

 

 

 

I know I'm late to the game here but I don't get on too much lately.  But the beautiful thing about Lego is you "can" just rest the board inside a model and not worry about it shorting out. I do recommend covering the board in some sort of insulation sleeve though.  I run lighting boards in some of my locos and they have gotten hot enough to leave little pin pricks in the side of the bricks they rest against before I installed heat shrink. (I also run my trains for several hours continuously at shows) 

Edit : love what you did for the tram