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Newbie... Need help with wiring kids car

Thunderface

May 15, 2023
6
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May 15, 2023
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I have a Kids Battery Powered vehicle I want to upgrade.



It is 12V & I want to convert it to run faster & for longer. I will use a Dewalt 20V battery to power it. I have purchased an adaptor with an inline 30a amp fuse for the battery. I also purchased a voltage controller to dial the speed of the motors as desired.



https://www.amazon.ca/gp/aw/d/B0995KCNB4/ref=ya_aw_od_pi?ie=UTF8&psc=1



https://www.amazon.ca/gp/aw/d/B08R7H4D3K/ref=ya_aw_od_pi?ie=UTF8&psc=1



As far I know this will work to speed up the motors (which i will up grade to 24V motors). My concern is the electronics in the car. The lights & stereo. I would like them to continue to run on 12V. I've read that a buck converter could be used to drop down the voltage before it gets to the electronics. Something like this:



https://www.amazon.ca/gp/aw/d/B078Q1624B/ref=ox_sc_act_image_1?smid=AFHAE9RJVUMB&psc=1



or this



https://www.amazon.ca/gp/aw/d/B076H3XHXP/ref=ox_sc_saved_image_2?smid=A3JJM7S8SDXVXM&psc=1



But I don't know where to add this in the circuit.



From what I can see, the best place to put it is somewhere after this 7 pin connector coming from the main circuit board. Its where all electronics get powered from. Any thoughts how I can do this?
 

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Delta Prime

Jul 29, 2020
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Well let's see power in watts=V× I,
20Volts × 30amps= 600Watts of Power
At your child's disposal. Does anyone else smell burning flesh well before your fuse blows. It's a recipe for transportation to the child's burn unit. :rolleyes:
 

Thunderface

May 15, 2023
6
Joined
May 15, 2023
Messages
6
Well let's see power in watts=V× I,
20Volts × 30amps= 600Watts of Power
At your child's disposal. Does anyone else smell burning flesh well before your fuse blows. It's a recipe for transportation to the child's burn unit. :rolleyes:
lol Thats what the voltage controller would be for, to dial to taste. But as for my question of how to keep the electronics from frying? Can you help?
 

Bluejets

Oct 5, 2014
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As far I know this will work to speed up the motors (which i will up grade to 24V motors).
There is nothing to say any 24v motor will run any faster than what you already have.
As it stands, you say replace battery with Dewalt 20v unit, which is in a way, advertising hype.
There is no difference between the old 18v and this new claimed 20v unit.
These units are made up of lithium ion cells which have a "nominal" voltage of 3.7v and if there are 5 cells in series, 5 * 3.7 = 18.5 nominal.
If one were to take the full charge level, ie the voltage the cell is charged to in a controlled charger, one would have 5 x 4.2 = 22v.
However, this latter level soon depletes down to the nominal level.
Look further at battery university site for charts, graphs and general information.

That said, a 24v motor with the right selection may have more power, depends what you pick, however it will be running on 18v ( :(:(:() so backwards move there.
Same initial details with a 12v motor with the right selection.

As for the buck converter, any that would handle the current of the accessories (or more) and has a rating higher in voltage than the maximum permissible by the buck converter specs. would be ok.
 

Thunderface

May 15, 2023
6
Joined
May 15, 2023
Messages
6
There is nothing to say any 24v motor will run any faster than what you already have.
As it stands, you say replace battery with Dewalt 20v unit, which is in a way, advertising hype.
There is no difference between the old 18v and this new claimed 20v unit.
These units are made up of lithium ion cells which have a "nominal" voltage of 3.7v and if there are 5 cells in series, 5 * 3.7 = 18.5 nominal.
If one were to take the full charge level, ie the voltage the cell is charged to in a controlled charger, one would have 5 x 4.2 = 22v.
However, this latter level soon depletes down to the nominal level.
Look further at battery university site for charts, graphs and general information.

That said, a 24v motor with the right selection may have more power, depends what you pick, however it will be running on 18v ( :(:(:() so backwards move there.
Same initial details with a 12v motor with the right selection.

As for the buck converter, any that would handle the current of the accessories (or more) and has a rating higher in voltage than the maximum permissible by the buck converter specs. would be ok.
thanks for the quick reply! :)

Yes 20v or 18v... either way it'll be an upgrade over the old 12v battery which isn't really holding a charge anymore. The reason I'm going to use the dewalt battery is because i have a bunch of them so it's convenient for me. So in your opinion the 12v 9000rpm motor i have in right now is fine? I was worried 18~20v would potentially fry it...

Im glad to hear a buck converter will work. Can you help me in where itd be best to hook up? Thats my main question. I don't know how & where to hook it up.

Thank you
 

Thunderface

May 15, 2023
6
Joined
May 15, 2023
Messages
6
There is nothing to say any 24v motor will run any faster than what you already have.
As it stands, you say replace battery with Dewalt 20v unit, which is in a way, advertising hype.
There is no difference between the old 18v and this new claimed 20v unit.
These units are made up of lithium ion cells which have a "nominal" voltage of 3.7v and if there are 5 cells in series, 5 * 3.7 = 18.5 nominal.
If one were to take the full charge level, ie the voltage the cell is charged to in a controlled charger, one would have 5 x 4.2 = 22v.
However, this latter level soon depletes down to the nominal level.
Look further at battery university site for charts, graphs and general information.

That said, a 24v motor with the right selection may have more power, depends what you pick, however it will be running on 18v ( :(:(:() so backwards move there.
Same initial details with a 12v motor with the right selection.

As for the buck converter, any that would handle the current of the accessories (or more) and has a rating higher in voltage than the maximum permissible by the buck converter specs. would be ok.
?
 

Bluejets

Oct 5, 2014
6,939
Joined
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Messages
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So in your opinion the 12v 9000rpm motor i have in right now is fine? I was worried 18~20v would potentially fry it...
You said you were replacing that motor with a 24v motor.....what is it you are actually doing now?
Apart from that, motors are inherently fairly robust and the 12v motor run on nominal 18v may not be a problem, depends on many things.
For example, we used an old Makita 7.2v drill (which had a knackered battery) threw away the battery alltogether and soldered figure 8 flex directly into the drill and ran from a 12v car battery (for bench or on-the-road use)
Works fine even after 10 years ( intermittent use)

It's really one of those "suck it and see" situations. (too many unknown variables this end to give any educated comment)
Run it for a short time and see how it goes.
If not over heating after a few minutes, then I'd say you are fine.

As a further note, let the kid drive the car, fairly certain you stick your butt in the seat will overload the whole shebang. :cool::cool:
 
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Thunderface

May 15, 2023
6
Joined
May 15, 2023
Messages
6
You said you were replacing that motor with a 24v motor.....what is it you are actually doing now?
Apart from that, motors are inherently fairly robust and the 12v motor run on nominal 18v may not be a problem, depends on many things.
For example, we used an old Makita 7.2v drill (which had a knackered battery) threw away the battery alltogether and soldered figure 8 flex directly into the drill and ran from a 12v car battery (for bench or on-the-road use)
Works fine even after 10 years ( intermittent use)

It's really one of those "suck it and see" situations. (too many unknown variables this end to give any educated comment)
Run it for a short time and see how it goes.
If not over heating after a few minutes, then I'd say you are fine.

As a further note, let the kid drive the car, fairly certain you stick your butt in the seat will overload the whole shebang. :cool::cool:
Yes, I was going to swap the motors with 24v motors. Sorry, maybe I misinterpreted your previous response where you said a 24v motor may not run any faster than what i already have. That's why I asked if you thought the 12v would be ok then...

I have no desire to drive the car lmao it'll be just my 6 year old nephew :p

Ok, and do you have any thoughts about running the other electronic at up to 18v? Is there a way I can be able to send the extra voltage to the motors but not to the other electronic? ie lights & radio? This is my main question I need help with....

I want to send up to 18v to motors...But I don't want to fry electronics like lights & radio.
 

Bluejets

Oct 5, 2014
6,939
Joined
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Yes, you will need some form of voltage regulator there BUT.................
What is the estimated current draw for the accessories such as lights, and radio etc.

If you look on Mouser or one of those online shops (even Ebay or whatever) you'll find plenty of buck converters.
Rather inexpensive for what you get....say one with 6 to 40v input and output current of around 10 to 15amp is around $15.
 
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