EV3 AC Power Adapter

[pdmarsh]

Is it possible to run the Mindstorms EV3 with an AC power adapter?  I don't have a rechargeable battery for it, but could that be used and simply kept on charge while powering the device?  My current application using the EV3 just isn't practical with battery power alone.

Thanks,
Paul

[2GodBDGlory]

Yeah, I'm pretty sure I remember seeing people just running their EV3s off of rechargeable batteries constantly plugged in! Personally I'd probably make a custom adapter to eliminate batteries entirely, but I think the rechargeable should be a good off-the-shelf solution.

[pdmarsh]

3 hours ago, 2GodBDGlory said:

Yeah, I'm pretty sure I remember seeing people just running their EV3s off of rechargeable batteries constantly plugged in! Personally I'd probably make a custom adapter to eliminate batteries entirely, but I think the rechargeable should be a good off-the-shelf solution.

Thank you 2GodBDGlory.  I had a feeling that might be the solution.  I did think about a custom adapter, but I don't know much about electronics and how the battery holders are wired internally, i.e. in series or parallel, also amperage and all of that.  I know the terms, but not the practice.

Paul

[Heppu]

I 3D printed a new battery box cover for my EV3 for a custom AC adapter earlier this year.

Material list is:

• 3D printed battery box cover (Stl file uploaded here: https://bricksafe.com/pages/Heppu/wip-/ac-adapter)
• 2x 15mm M2.5 screws
• DC barrel jack socket
• AC/DC wall power adapter 12V/3A (9V/2A is enough for most use cases)
• Electrical wires (red=plus, black=minus in above picture)
• Battery holder clip from a AA battery box & a metallic washer as contact points to EV3
• (Hot glue for attatching the battery clip & tin to solder the electrical wires)

Hope this helps anyone attempting to do similar projects :) I'm always open to answer questions if needed.

Philo has instructions for a similar project for Mindstorms NXT: https://www.philohome.com/nxtsupply/nxtsupply.htm Hes' is maybe better than mine having a fuse, but I've had no problesm with mine so far.

 

Edited July 5, 2023 by Heppu

[pdmarsh]

Thank you, Heppu!  I happen to have a 3D printer and even printed a battery cover for an old NXT a while ago.  With your instructions I think I can do this.

Paul

[Mr Jos]

Well done @Heppu I would have liked it 100% if it would clip in like original instead of using screws.

For now I use the Lego rechargeable batteries and constantly plug them in during events (8h+ running/day). A solution like these DIY would be good for me, to save the life of these batteries. Now I have 12 EV3 bricks and 11 batteries.

I modified a laptop charger to be able to charge 8 EV3 bricks at a time (with 2m long cables each, soldered together) from 1x 230V AC socket -> 12V DC 5A

[2GodBDGlory]

On 7/5/2023 at 11:56 AM, Heppu said:

I 3D printed a new battery box cover for my EV3 for a custom AC adapter earlier this year.

 

Material list is:

• 3D printed battery box cover (Stl file uploaded here: https://bricksafe.com/pages/Heppu/wip-/ac-adapter)
• 2x 15mm M2.5 screws
• DC barrel jack socket
• AC/DC wall power adapter 12V/3A (9V/2A is enough for most use cases)
• Electrical wires (red=plus, black=minus in above picture)
• Battery holder clip from a AA battery box & a metallic washer as contact points to EV3
• (Hot glue for attatching the battery clip & tin to solder the electrical wires)

Hope this helps anyone attempting to do similar projects :) I'm always open to answer questions if needed.

Philo has instructions for a similar project for Mindstorms NXT: https://www.philohome.com/nxtsupply/nxtsupply.htm Hes' is maybe better than mine having a fuse, but I've had no problesm with mine so far.

 

Cool! I might have to look into printing that for myself!

I recently picked up all the EV3 electronics (minus the touch sensor) from my brother for ~$90 CAD (~$70 USD), after he bought the kit for about that from a thrift store, so if/when I get around to playing with it a bit more, such a solution would be very handy!

[Heppu]

Thanks all, hope this proves to be useful to others as well!

6 hours ago, Mr Jos said:

Well done @Heppu I would have liked it 100% if it would clip in like original instead of using screws.

I actually started out with designing a clip version, but creating small elastic clips that don't break is really hard with a 3D printed part. Also in my version due to the compressed tension in the battery holder clips, the screws are mandatory to hold the lid in place. The electronics would need to be separate from the cover for a clip version to be possible.

[kieran]

Very nice