cordless drill conversion

SPYDERLK · Oct 21, 2011

k0ua said:
I will bet a dollar (yes I will send you the dollar!) that his little Black and Decker 9 volt wont draw 10 amps under full stall at 12 volts. One way to find out is to measure it.! Thats why I suggested to measure it. Then we can size the fuse and the wire size a little better. Sure I am guessing, but so are you, without measuring it is all just speculation.

James K0UA

Its a bet. If the OP will put various value standard blow fuses wired into the feed wires itll give an ~answer w/o the need for measuing equip. He should use 12ga wire and iterate up or down from 30A as indicated by fuse survival for a minimum of 3 sec at stall. [A fuse wont blow at its rating and typically a std fuse will take a second or two to blow when conducting twice its rating.]
larry

k0ua · Oct 21, 2011

SPYDERLK said:
Its a bet. If the OP will put various value standard blow fuses wires in the feed wires itll give an ~answer w/o the need for measuing equip. He should use 12ga wire and iterate up or down from 30A as indicated by fuse survival for a minimum of 3 sec at stall. [A fuse wont blow at its rating and typically a std fuse will take a second or two to blow when conducting twice its rating.]
larry

Sounds like good methodology its a deal. (what was that address again

)

James K0UA

SPYDERLK · Oct 21, 2011

k0ua said:
Sounds like good methodology its a deal. (what was that address again)

James K0UA

Dont worry about it. Lets see if we can get him to try it and report.:thumbsup:
larry

k0ua · Oct 21, 2011

Yeah hard to say what the OP will do. of course some depends on the size and the length of wire he uses. I was thinking the little B&D 9.6 volt was a pretty anemic drill and not having much torque was likely to have a small current draw.

James K0UA

SPYDERLK · Oct 21, 2011

Hard to ask him to hold his motor at or near stall for several seconds. Things heat up pretty quick. No way to be sure on his drill. Youll see tho on the specs of AC handrills that they fall in the range of 2 to 4A rated running current. The lower of that is truly anemic. At 12V you need 10x that. Then near stall it goes up another factor of 2. The ability of NiCads to deliver current is astounding ... the better part of 100A from a "C" cell. Not for long but plenty of grunt while it lasts. NiMh cells pack more energy but cant deliver the current ... so the drill can run lite duty longer, but cant put out hi torque at all.-- And lithium has it all.

larry

garry · Oct 21, 2011

Thanks for all the replies and encouragement. I will get some supplies next week and give it a try. I will keep you posted.

schmism · Oct 21, 2011

I converted one of my old 12v drills to be corded and attached to a lawn mower bat.

I just soldered 2 wires to the pads on the side of the old cordless bat. that way the drill itself has not been modified and i can use the cordless as one if i ever get around to rebuilding one of the other 12v bat packs.

PILOON · Oct 21, 2011

I have opened a few battery drills and repaired many.
I noticed that be it 7.2, 9 or 12 volts the motors all seem the same.
True I did not measure winding resistance but swapping parts around generally worked OK.
I also have wired some drills to the cigar lighter plug and it is sure handy to have.
Most lighter plug adapters have fuses built in.

crbr · Oct 21, 2011

garry said:
Thanks for all the replies and encouragement. I will get some supplies next week and give it a try. I will keep you posted.

Thank you....

handirifle · Oct 22, 2011

Well, I have an old Makita (I think I still do anyway) whos battery died and I have lost the charger. The battery dies many years ago, but I kept it all thinking someday I'd buy a new battery, went with a corded drill instead.

The posts here now have me thinking. I tried some of the "youtube" ideas on refreshing the battery, to no avail, but other ideas here are intriguing.