Help me convert my old drills

[Christophe Mineau]

Hi Folks,
Here it is, I ended up with my solution.
I spent my evening and part of night making that.
Actually, by the time being, I am playing again with digital electonics (arduino, great fun ), and had to purchase some components. And I decided to look for a simple bench power supply, and I found a very interresting and very powerful 12V power supply for a reasonable price (33€ on ebay, postage included).
It's 12v / 20 A. So I got it yesterday... of course, I decided to buy it thinking about my drill, no need of 20A for arduinos .
Give me just a little time and I will present it as a new tool;
It works perfect, and it's exactly what I needed.
Christophe

Edit : here is my solution :
http://www.homemadetools.net/forum/c...5837#post21001

[cuyler1]

i love these threads. i have a lawn mower battery with a harbor freight float charger in a milk crate attached to a hand truck with cable ties on 1st layer. then a 2nd. milk crate with 1/4" plywood on each side and top for holster mounts for 2 drill motors. stereo mounts to top and speakers stick to hand truck rails. it has 2-3 place 12vdc outlets ran to the battery and flush mounted on the front of 2nd. milk crate. robe hooks to wrap 16 gauge repurposed extension cord in 10' lengths attach to 7,2v and 12 volt drill motors that had dead batteries. building a 12vdc trouble light with leds at the moment for it. i used it 8 years ago to install a privacy fence. 1 to pilot drill holes and one to drive screws along with my new cordless ones. lengths and size of cords crucial!

[sewoodruff]

Hello,
That's a great topic,
I've been looking for something similar for a long time.
The reason is not that my battery pack is out of order, the reason is that whenever I have to screw something in my shop, (that's not so often, not every week end), my three battery packs are always flat.
And as I don't want to plan several hours ahead that I have to screw something, I use the cordless drill very rarely.
As I am in my shop, I have no problem with the cord, and would prefer to have a tool always ready to use, even with a cord, rather than an always flat cordless tool.
And I don't want neither to have the battery charger always plugged, in case of an hypothetical use ....

I've always wondered why the manufacturers don't do such corded power screw drivers. I sometimes use my electric hand drill, but I really miss the torque limitation and the speed is too difficult to control.

My drill has the bad idea to be 14.4 V, so I guess using something like a car battery charger of 12 V would not fit ?
However, would that be so damaging for the motor to be 12V powered instead of 14.4 V ?

Diyer, I like the third solution you provided, that's exactly what I need, but will it be possible to find a bridge rectifier or regulator to convert from 18V AC to 14.4 DC ?
There are also lots of solutions over the Web making use of Laptop chargers, but I never considered these kind of solutions as serious, I feel that the current pick in real use would be far superior as what they could supply.

Thanks notagoodwelder for posting the question, and sorry if I 'm invading your topic.
Christophe

Christophe,

I had the same problem and my solution was after recharging the battery I plugged the charger into a timer. You know the same kind people put their lights on when they go on vacation. I started out with a short time each day and increased the time until the battery still had full voltage after two weeks. The timer was cheap and I still had the convenience of a cordless drill.

Glad to know I wasn't alone with this problem.
Steve W.

[neshkoro]

I have been having the same problems with thise expensive drills and dead batteries.
My solution was to spend $20.00 at Harbor Freight and buy one of their cheap drills and they come with a battery and a charger.
I have 3 of them now and they work just fine. When they die I will just trash them and buy a new one for another $20.00.

[kbalch]

This thread has been moved to the Must Read subforum. Congrats (and thanks) to notagoodwelder for making such a valuable contribution!

[cuyler1]

i do not work for sunn battery but i have a friend who has for 40 yrs. i visited him one day and was looking at their mainstay, golf cart batteries, and wondered off to the back wall where all the rechargeable ones for the ones these thread refers to as the burnt up ones. through the door was a bunch of pretty ladies welding replacement battery packs for cordless drill motors. when asked he told me buying through them at that location cost was dirt dirt cheap. maybe if you visited a golf cart battery store (in person not over the phone) maybe they have the same set-up. i started looking at the carbon arc spot welders built here with micro wave or old car battery chargers and i'm thinking i might go back and buy of the rack replacements- then assemble!

[Jerry L]

I think you will find with a battery charger unless running in start mode you will not have enough amperage to power the drill under any load what I have done with my 14.4 volt drill is wire it to an old battery uing the cord off an old vaccum having been using this drill a couple years like this frequently only needing to recharge battery every 2 to 3 months the battery i am using still holds a charge but was no longer suffcient to start my truck no need for new battery for this project will try to post pics next week

[volksman]

taking the battery case appart and taking out the old cells leaves an empty case. lipo batteries for model airplanes can be bought cheap enough. ive seen a twelve volt drill made with nicad pack striped and a lipo replacing it. wow turned a junk drill into a good tool again

[cuyler1]

the friend i had at sunn battery passed 3 weeks ago but in conversing with him prior he explained about the hazards of lipo's. they are charged differently and really should be charged with a lipo one. but me being me take the chance and charge these one by one on a 3.7vdc phone charger. have to babysit them to keep from over-charging or they will self destruct.

[volksman]

Yes they are charged differently. I fly model airplanes and have the. Proper .charging gear