How to modify your Lego Technic Battery Box. Save on Batteries! More Power!

[@TechnicBrickPower]

Check out my website for my great Lego Technic content technicbrickpower.com 🙃

[@JoranPrins]

I just connected a power supply right to a cut up converter cable. It works good, and is more space efficient.

[@matchboxmickmoyboyz6988]

Make sure you press down on the grey connector section when pulling apart. First one I tried it rippoed the connector block off the printed circuit board. Nice solution though to get rid of the batteries.

[@bami2]

As a kid I bought a DC barrel connector plug to 2 loose wires cable (very cheap everywhere), wrapped the cable ends around nails, hammered them in the top of wooden dowels the same diameter and length as AA batteries and jammed them in the top two battery slots of the old 9V battery box so they would make contact to the terminals. A small nick in the housing to let the cable out, connect a random DC wall wart (those ungeared 74569 motors really go brr when you run them at 12v) and never had to recharge a single battery again.

[@TechnicBrickPower]

I like it! very creative. 🙃👏

[@Sapple498]

Thank you for the video! It helped me modify the battery box in a completely different way. I only needed one battery to push 1.0-1.5V through to my M-motor. The build is a 78 cm tall wind turbine and with a 1:1 gear ratio, I can get the blades to spin at a semi-realistic rpm.

[@TechnicBrickPower]

Hi Saku. Are you really running a motor off 1 battery? That's interesting - never knew it could do that ! Thanks for sharing. 🙃

[@Sapple498]

@@TechnicBrickPower With a piece of aluminium foil, yes! :D The motor obviously has almost no torque, so there mustn't be almost any resistance

[@MrSupermule]

nice mod, a small correction, the gizmo after the batteries is actually a polyfuse, think of it as a self-resetting fuse that protects motors and wires from overload

[@TechnicBrickPower]

Hi Claes, ah yes thanks for that. When I first saw it, it looked like a capacitor but yes a fuse makes more sense. Thanks for your input! 🙃

[@juliosilva6008]

There's no sense to put a capacitor in series in DC current... you should add a text correction saying its an auto re-armable fuse and not a capacitor. So who is learning won't be mistaken.

[@timnewland4186]

Bought some bits off ebay. Followed your advice and absolutely chuffed to bits with the result. This was just the fix I was looking for. Thank you so much for sharing 😀😀😀

[@andylewis3461]

More power Egor!!! Short out the 750mA polyfuse. Current limit your PSU to no more than 2.0A with those weeny wires though!

[@TechnicBrickPower]

Hi Andy, yeah no idea how amps they can handle! 😂

[@josfrankena4891]

As if there are more screws hidden in the battery pack I try to modify. I can't get it open/separated! It is just the modification I was looking for. Maybe use WD40?

[@jclark9372]

Very clear video. Thanks for showing how to do this.

[@happyhippo4664]

Good idea. I was thinking of making one with a barrel connector from a AC/DC wall converter- that way, it is a plug. Also, I was thinking of making another one with 3 3.7V rechargeable Lithium AA cells. But I would hate to keep taking them out to recharge. I'd have to have the charger external, which I guess is doable. Also, don't know if the motors would like the slightly higher voltage. They are 12 V motors but I think they'd last longer at 9 V.

[@woutervankoppen3927]

Do you have a link where does small cables and connectors can be bought? So far I cannot find them on AliExpress or eBay.

[@TechnicBrickPower]

Hi Wouter. What type of cables & connectors? You mean Lego ones or just general electrical ones? 🙃

[@woutervankoppen3927]

@@TechnicBrickPower thanks for your reply. I mean the type of cable connector as shown in the video.

[@TechnicBrickPower]

Hi Wouter. I got mine from our local electronics shop in NZ. Here's the link that may help you find them else where. www.jaycar.co.nz/jst-crimp-connectors-2-way/p/PT4452 🙃

[@woutervankoppen3927]

@@TechnicBrickPower 🙏 thanks!

[@TechnicBrickPower]

@@woutervankoppen3927 Hi Wouter, I can send you some if you can't get your own.

[@somedude7633]

You must have the hands of a rock climber, because I feel like I’m going to break my fingers before the battery rack comes out…. Any suggestions?

[@somedude7633]

Also, this isn’t the first time you opened this battery box. How did you open it the first time? 2:42

[@Crlarl]

If the point is to use wall power instead of batteries, why not use 4548 and 8886 together?

[@normanszalai1489]

because maybe you dont wanna buy them if you dont have them lying around...

[@DragonXDrei]

Or you could buy something like the Lumineo battery replacement unit used for Xmas lights:))

[@TechnicBrickPower]

Hi yeah I guess...but then it wouldn't be pure lego! 😂

[@caosoftware]

it is possible to put inside the battery box a 11.1 V 3600 mah battery pack ?, and how to adapt the voltage to receiver, I tried a resistor but not works , the system heats so much

[@TechnicBrickPower]

Hi mmm you can't easily reduce 11v to 9v DC. A voltage divider using a resistors is an option but will lose a lot of power (and generate heat as you have found...)

[@kiidan]

Are you a man with super power or some sort? Because I tried to pull them apart but they won't move at all. And you do it just so easily, without any effort at all!

[@TechnicBrickPower]

Hi Rizki, Strange - maybe there are different version of the battery power packs that do not open...? 🙃

[@daweidrake]

There are at least 2 unique part numbers for these battery boxes. 41M5 is hard to get apart.

[@arcticowl1091]

Ihave a 17N9 and its the same, this damn thing will not come apart

[@somedude7633]

2:42 note the deeper channels on the sides (3 per). This is probably the thousandth time he’s done it with this box. He must have used some destructive means in the first place that he’s not telling us about.

[@mrcoolgs100]

Unfortunately, not enough warning given on the pulling out, I just ripped off the wiring from the lego connector

[@TechnicBrickPower]

Sorry to hear that... did you manage to fix it?

[@normanszalai1489]

really helped! imma use this to rotate the meat in the smoker overnight :) xD

[@samw4794]

What is the rpm of the motor when it is connected to that power supply?

[@TechnicBrickPower]

Hi Sam, thanks for the question. The power supply has a variable voltage and if you set it to 9v then the RPM of the motor is the same as it would be if you use 9v worth of batteries. Typically for a lego technic "medium" PF motor is about 400 RPM at 9v. However the benefit of the power supply is that you can reduce the voltage and since the RPM of a DC motor is almost linear with the voltage the RPM reduces also. So that means if you set the voltage to half (e.g. 4.5 v) then the motor will rotate at half the speed, i.e. 200 RPM. You can also increase the RPM by increasing the voltage - but risking overheating the motor and burning it out (I think it does have some protection against this built in). Also the power supply has a lower internal resistance meaning the output voltage does not drop with increasing current which can happen with batteries.

[@samw4794]

@@TechnicBrickPower Thanks a lot

[@kevinsansouci9166]

Can you build a 4 by 2 stud chargeable battery box please I'll buy it for 10 bucks

[@jelmerjansen328]

Hey bro i have a question, can i use a adapter 12 volts 2000 mili ampere instead of a power supply??👊😊

[@wassup9777]

heck yeah bro. I connected my rc battery to it and it works like a charm.

[@mrman7790]

Thanks

[@alexdanias7844]

Can you do this without a sotering iron

[@TechnicBrickPower]

Hi Alex. Probably not...unless you can find some clips to connect with.

[@jelmerjansen328]

Perfect bro 👌

[@TechnicBrickPower]

Thank you so much 😀

[@undoredoit4075]

Really nice mod, batteries are bad and expensive, this is a nice solution!

[@TechnicBrickPower]

Thank you, yes good to reduce batteries in the world. Glad you liked the video - please subscribe if you'd like to see more.

[@Bricksfaction]

Very useful

[@TechnicBrickPower]

Thanks - I use it a lot! I always find my battery packs are half dead and so my designs don't work as well. But with a permanent power pack - no problem.