Shopsmith Forums

dusty wrote:I began this process yesterday. I find that I have three or four cells that measure 0 volts. Assuming that those cells are shorted, this process may not work. That is yet to be seen.

It is a roll of the dice. Those fingers are not the only thing that causes them to 'go bad'. Those with 'fingers' are fixed(for a while) by zapping.

Re charging first, me thinks the opposite would be more logical. One problem with zapping the series string is that the 'bad' cells are usually depleted whilebthe 'gooduns' are not. Further charging(to get the badun' charged) results in excessive charging of the gooduns. Discharging the battery first will at first reverse charge the baduns, but upon depletion, all should be equal. then all get charged the same amount.

By getting down to the cell level you can attack where needed exclusively. Getting an individual cell charged be a logistic 'problem' if variable supply not availablr.

JPG40504 wrote:3 bad cells! Maybe more(longer discharge will tell that tale).

Should I just put it in the drill and let it run until it no longer rotates?

robinson46176 wrote:I haven't seen it mentioned here but the original instructions for this that I saw said to put the battery through a full recharge cycle before zapping it. Was that done here? I have no idea exactly what that is supposed to accomplish. It may be valid or it may be like standing on one foot while zapping.

I didn't recharge prior to zapping. Wasn't aware of that process step. Do you recall where you saw that? I've found scant technical reading on zapping these Ni-Cd batteries.

horologist wrote:Mike,

Good work. If you have a few bad cells as JPG says then I wonder if the remainder of the cells are going to be much better. Would it be better to replace all of the cells? Are these things readily available in small quantities? I know there are people who advertise reconditioned lap top batteries for about half the price of new so it is possible.

Troy

I don't know enough about Ni-Cd technology to know the longevity of the 'good' ones. I've read that quality batteries properly maintained (exercised) can last several years. Again here, found scant technical info. Also don't know how easy it is to get individual cells. Good question. Since I have 3 packs that are not working correctly, I could scavenge 'good' cells from one of the packs if I wanted.

dusty wrote:I began this process yesterday. I find that I have three or four cells that measure 0 volts. Assuming that those cells are shorted, this process may not work. That is yet to be seen.

Glad to see you joined the fun dusty. Be safe though. I made sure to use a face shield in the event of a 'popper'.





The source I came across that seemed to best cover the technical aspects of the batteries talked about zapping as a method of actually increasing a batteries voltage potential vs. saving one. They mention using a capacitor to zap saying "The zapping is done with a 47,000mF capacitor that is charged to 90V. Best results are achieved if the battery is cycled twice after treatment, then is zapped again.......". Again, they are talking about doing this to good batteries.

Should anyone locate other good reading on bringing the Ni-Cd's back to life, post it in this thread. My plans are to work on mine a bit more before throwing in the towel but as I mentioned, I don't know right now what plan B is. My gut says to zap it BIG TIME but I have no technical reason to feel that way. My primary concern is being safe. After all, the new batteries are only $30.

If anything, this experience has taught me to maintain my Ni-Cd's better. Too often, I use my tools, put them in the cabinet and forget about them until the next time I need them. What I've read says they need to be maintain (exercised) monthly. I've created a reoccurring monthly task in Microsoft Outlook to do this so that I don't forget.

Keep the thread rolling.

I found thisa while back, when this discussion first arose. I don't know how technically reliable it is but I am certain it rises above my level of expertise.

At any rate, I zapped just the bad cells because the others were up around 1.2 - 1.3 volts. I chose to zap only the .000 volt cells.

The pack is now in the charger and it indicates a charge cycle is in progress. Previous, the charger would not go there.

We shall see what we shall see. Now I gotta go look for that battery that was suppose to on the way to the recycle barrel at Home Depot.

About being safe...
We have used a little dynamite here years ago and one of the first rules is if you are setting it off with a momentary contact to a battery you make that contact "AT THE BATTERY" Not the blasting cap.
Instead of contacting the battery being zapped, connect a lead to it and make the momentary contact from way back...

JPG40504 wrote:It is a roll of the dice. Those fingers are not the only thing that causes them to 'go bad'. Those with 'fingers' are fixed(for a while) by zapping.

Re charging first, me thinks the opposite would be more logical. One problem with zapping the series string is that the 'bad' cells are usually depleted whilebthe 'gooduns' are not. Further charging(to get the badun' charged) results in excessive charging of the gooduns. Discharging the battery first will at first reverse charge the baduns, but upon depletion, all should be equal. then all get charged the same amount.

By getting down to the cell level you can attack where needed exclusively. Getting an individual cell charged be a logistic 'problem' if variable supply not availablr.

I have a variable supply but I am not inclined to use it on this task.

The battery charger will take care of that. I will simply leave the charger on for what DeWalt refers to as a "Maintenance Charge Mode" after which time I will put it into the "tune up" mode. The manual recommends that this be done every 10 charges.

dusty wrote:I found thisa while back, when this discussion first arose. I don't know how technically reliable it is but I am certain it rises above my level of expertise.

At any rate, I zapped just the bad cells because the others were up around 1.2 - 1.3 volts. I chose to zap only the .000 volt cells.

The pack is now in the charger and it indicates a charge cycle is in progress. Previous, the charger would not go there.

We shall see what we shall see. Now I gotta go look for that battery that was suppose to on the way to the recycle barrel at Home Depot.

For the reconrd, tell us the details about the zap process used. How many 0V cells did you have?

robinson46176 wrote:About being safe...
We have used a little dynamite here years ago and one of the first rules is if you are setting it off with a momentary contact to a battery you make that contact "AT THE BATTERY" Not the blasting cap.
Instead of contacting the battery being zapped, connect a lead to it and make the momentary contact from way back...

I wonder if that applies to these sealed batteries? I know I have ALWAYS avoided sparks around a car battery by making the final connection with the negative to metal on the vehicle vs. the negative post on the battery. That's the way I was taught. Now that batteries are sealed, I don't even know if that's recommended anymore. Any idea?

Found some other good battery reading.

http://batteryuniversity.com/learn/

and

http://michaelbluejay.com/batteries/#nicad

mickyd,
I use the Ryobi 18V ONE+ system because I got tired of trying to keep up with three or four different charging systems and battery types. I also got tired of having one or two chargers even with the ONE+ system. So, this Christmas I bought myself a present that will keep all 6 (4 ni-cad 2 li-on) of my Ryobi batteries charged, maintained and ready to go at all times. It's a ONE+ six station battery charging system. It's a little pricey, but I think it will save money in the long run.

Check it out HERE.

curiousgeorge wrote:mickyd,
I use the Ryobi 18V ONE+ system because I got tired of trying to keep up with three or four different charging systems and battery types. I also got tired of having one or two chargers even with the ONE+ system. So, this Christmas I bought myself a present that will keep all 6 (4 ni-cad 2 li-on) of my Ryobi batteries charged, maintained and ready to go at all times. It's a ONE+ six station battery charging system. It's a little pricey, but I think it will save money in the long run.

Check it out HERE.

Ain't it great when you're your own Santa Clause? I do it all the time!!

I was surprised to see the price at under $60. Looks like a pretty good deal to me.

I wonder if this unit also 'exercises' the batteries for those who don't use them consistently or if keeping them topped off is sufficient for extended life?