Building 18V 10A power supply for power drill

[nick_hags]

Hello Everyone,
I was recently given a battery powered drill with no batteries (hence, why it was free), and I'm looking to make it into a corded drill. I understand that it would be much safer and easier to just go and buy the right power supply, but I enjoy electronics projects like this, and it typically comes out cheaper to make it yourself anyway. The problem I've run into is the drill runs up to 10A at 18V and I can't find any plausible solution to that. Does anyone have any recommendations on parts or builds? I have 3A diodes that I was going to hook up in parallel in a diode rectifier format.
Thanks!

 

[InvalidError]

I enjoy electronics projects like this, and it typically comes out cheaper to make it yourself anyway.

You can build a DIY power supply for cheaper than $20-50 off-brand replacement batteries and chargers on Amazon? Unless you happen to have all the parts on-hands from scavenging, building a proper 200W PSU from scratch as a one-shot project would cost over $50 in new parts. The simpler and cheaper option would be modding a ~$50 250-300W 24V LED driver by simply reducing its open-loop voltage limit to 18-20V, only need to change a $0.01 resistor.

 

[nick_hags]

I enjoy electronics projects like this, and it typically comes out cheaper to make it yourself anyway.

You can build a DIY power supply for cheaper than $20-50 off-brand replacement batteries and chargers on Amazon? Unless you happen to have all the parts on-hands from scavenging, building a proper 200W PSU from scratch as a one-shot project would cost over $50 in new parts. The simpler and cheaper option would be modding a ~$50 250-300W 24V LED driver by simply reducing its open-loop voltage limit to 18-20V, only need to change a $0.01 resistor.

A wired power supply would mean I never have to buy batteries for the lifetime of the tool/power supply, whichever goes first.

 

[InvalidError]

Also, if you're going to spend $50+ on converting a cordless drill into a corded one using a hacked-up power supply and rigged wiring, might as well just buy a proper AC-powered one for $30-50.

 

[nick_hags]

I bought a 70W variable voltage laptop charger for $10, and it will operate the power tools just fine, but I was worried about damage that it could be causing, so I did just purchase an off-brand battery and charger. cost around $35

 

[InvalidError]

I bought a 70W variable voltage laptop charger for $10, and it will operate the power tools just fine

If by 'fine' you mean pulling the trigger under no-load condition and getting it to turn to full speed, sure. But you won't reach the tool's torque spec with 70W when it normally requires 200+W. With 1/3 of max power, you can expect to get about 1/3 of max torque.

 

[nick_hags]

I bought a 70W variable voltage laptop charger for $10, and it will operate the power tools just fine

If by 'fine' you mean pulling the trigger under no-load condition and getting it to turn to full speed, sure. But you won't reach the tool's torque spec with 70W when it normally requires 200+W. With 1/3 of max power, you can expect to get about 1/3 of max torque.

I did not try it under load. I only need it for very light drilling and screwing, so I was hoping it would be okay. Thank you for your advice though. I'm glad I took it, even if it meant spending more.

 

[InvalidError]

Cordless drills/drivers are quite a bit more enjoyable in their intended form with a more proper weight distribution when the battery provides some counterweight and no cable to get tangled in. I know I wouldn't dream of converting mine to corded

I hope your aftermarket battery proves to be of decent quality.