Control board Issue with project

[Boydy83]

Hi guys,

Looking for some guidance here, as a project I changed the battery in my sons ride on car to accept my 18v dewalt battery and used a motor speed controller in order to lower the voltage, short story kids ramped it up and there was a bang.

Car stating battery low although it was fully charged, so took out the control board and the capacitor next to the battery input blew apart.

I changed that capacitor and freshened up some of the solder around, and installed an 18v to 12v step down this time, but it still won’t work states battery low, I checked voltage at connection it’s 12v I’m at a loss here board looks fine to me.

I did order a new control board but would still like to work out what else could of went wrong, Any help would be appreciated

 

[ZipZapOuch]

Instead of a stepdown voltage regulator, I would just make a PWM controller for the 18v source with a 65% max duty cycle. Keep the frequency of the PWM nice and high, and your motor won't notice the difference. Size all components for 35v or better.

 

[aliarifat794]

I think checking the PCB will be better. Maybe there is a broken trace somewhere.

 

[Tony Stewart]

Last time I upgraded a kid's car I replaced the 6V motorcycle battery with a small car's 12V battery. Then it could haul 3 little girls to the park and back.

 

[augustinetez]

At a rough guess, there appears to be some sort of microprocessor bottom left corner so jacking up the voltage has probably damaged that - it probably has a voltage divider type arrangement on an input to monitor battery voltage.

 

[ZipZapOuch]

Last time I upgraded a kid's car I replaced the 6V motorcycle battery with a small car's 12V battery. Then it could haul 3 little girls to the park and back.

I upgraded my first car to take 3 girls to a beach and back. All was good until one of the girl's dads showed up on my Dad's doorstep with a 12-gauge.