Some advice regards a 12v to 24v conversion

[Wezaa]

Hi, friend bought my son a cheap Chinese ride-on.
It has a Bluetooth remote for parental control too.
It is 12v with 2x 6v batteries.

I have replaced all of the batteries, replacing with 4x 6v 5ah batteries. (I went with 4x 6v due to the space available to put the batteries, could fit 2x 12v into the car.)

I wired it all up and it was great, for about 10 mins, then a pop and an electrical burning smell.
Disconnected the batteries and took a look, the control board is toast, a resistor popped and the board is burnt. It is one of these boards
It's a "Wellye Children's electric toy car 2.4G Bluetooth remote control, reveiver with smooth start function 12V" (I have found and ordered a replacement from China)



There is a 10a fuse that is between the positive (red) connector of the battery and the positive connection to this controller box. Yet the box still fried before the fuse did. I guess that means the voltage was too much for the control box?

Could anyone please reccomend a suitable 24v replacement that would work for this car? It has 3x 12v motors. One of each back wheel for forward/reverse and one connected to the steering column for steering via the Bluetooth parental remote.
I would still like to have a working remote for this if possible.

Or is there a way I can limit the voltage to the board but have the full 24v going to the motors?

Or maybe a way I can use a 24v board for say an electric scooter and also add a parental control unit?

Thank you.

[CJB]

Personal opinion only here, but I think these kinds of rides are crap, from a modders point of view. You can not up the voltage in a vehicle with this type of circuitry designed for 12v. It was made for 12v and to remain fully functional, must be kept at 12v.

What would I do if someone gave me one? Gut it. Pull all that garbage out and rewire the whole darn thing to work the way I want it to.

[TinCanTomCat]

I completely agree.

I found that every connection in my daughter's PW had some resistance, which on stock was tolerable, but anything beyond put too much stress on them, causing them to heat up.

Later, putting faster motors on completely cooked the connectors.
Replacing the connectors allowed too much current and blew the ESC's (inherent shoot-through issue hidden).

The stock stuff is all relay based anyway, so you can update it pretty cheaply.

As for this ESC, it would need to be modified to run 24v.
Internally it will likely have a regulator and associated circuitry for 12v input.
Running 24v was likely out of spec for the regulator and caps, causing overheat and failure.

You could reppacw the reg and add a heatsink (or far better, replace it with a cheap SMP buck module, no heatsink needed, dialed to the output voltage of the original regulator), and change the caps for 35v rated.

Personally I fitted a mobility scooter ESC, though you can get generic scooter modules and pedal for around £10-£15 ($/€20?) from China.
I then fitted a custom PCB, using an ESP8266, which I can control the car, or set limits on the child's control, via my phone browser.

[Wezaa]

Thanks so much for the reply. Unfortunately I am totally new to this and don't really understand a lot of the things you have mentioned, if you could please clear some things up?

What is an ESC?
What do you mean by regulator and caps?
What is an SMP buck module?

From reading the other thread, it would seem as though I can use the controller from a scooter, and wire that into the forward/pack/reverse switch and to the foot peddle?
How would I add in R/C to that?

Sorry for all the questions. Again, thank you for your help.

[Wezaa]

Ok, I know what an ESC is now. Haha

Would I able able to connect one of these
http://www.robotshop.com/uk/sabertooth- ... gK0HPD_BwE
Connecting the 2 rear motors to M1 and the front (steering motor) to M2 to enable drive and steering?

Would this Transmitter and receiver work with this ESC?
http://www.ebay.co.uk/itm/New-Flysky-FS ... 2548.l4275

[chart2006]

On first impressions you may be fine to use a Sabertooth with the Tx/Rx however I'd suggest at least jumping to the 2x25. The 2x12 won't give you enough current to drive the driver motors. That being said I'd also look into the steering servo. It may not support 24v which means either replacing it or some form of voltage divider may need to be added. I think the steering servo is probably going to be where you run into some issues.