Hi all… I have a question…
Im tring to run a rc car with one of the power drill battery
The original car battery is ni-cd 4.8 v
The drill battery is li-iON 18 v
Can I build a voltage regulator with a LM7805?
The datasheet says
input 7-25 v so I should be in the safe
Max current output 1.5 A again should be more than enough
Is that doable or I’m missing something?
Cheers
Yeah fine just will create a lot of heat so heatsink probably required
What might be more fun is building a car that a whole drill slots into as the drive train…
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What about a step down module? Someone in another blog suggest that!
How can I avoid the under charge effect of the li-iON batteries? I dint want to damage anything!
I like your idea of the drill but I don’t see how to manage the throttle…
Little servo on the button? Plus you’ve now maxed out my nano sized electronics knowledge…
Or, you make a dragster, goes forward, never stops 
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Also will be a 1 weel drive… Mmm Not gonna be stable!
Ha, I was thinking wed have at least four wheels!
Why 4v?
edit: just remembered your original post, trying to use the existing motor
Switching regulators are far better that standard 7805’s , something like the LM2596. More power and less heat. The 7805 gives off more heat the greater the voltage drop whereas the switching reg doesn’t care…
For the lipo, you can manage the battery with a processor monitoring the voltage or you can buy dedicated boards… If you over discharge them you Will kill them…
Courty
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…power tool drag racing, anyone?
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It will work but not very well , sorry
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is all I’m hearing. Lets do it!
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That’s the most sensible thing I’ve heard any one day in a long time!!! 
chain saws on roller blades? need i say more?
http://www.powertooldragraces.com/photogallery.html