The very fine short circuiting links are burned out by the zapper and must be very fine as it cannot be burned out safely otherwise.
Wacking it with a hammer possibly gives it a transverse shock wave that physically breaks the shorting links. But a microscopic break might easily build up again quickly !
The plus point might be that repeated shocks might work and the recharge lifetime might be longer than the electrical zapping system.
Maybe after the shock 'zapping' life time is over the electrical zapping system might work and prolong the lifetime...........! Just a thought .
Any thoughts ?
Wacking it with a hammer possibly gives it a transverse shock wave that physically breaks the shorting links. But a microscopic break might easily build up again quickly !
The plus point might be that repeated shocks might work and the recharge lifetime might be longer than the electrical zapping system.
Maybe after the shock 'zapping' life time is over the electrical zapping system might work and prolong the lifetime...........! Just a thought .
Any thoughts ?
Ron E
Thank your for responding and for being such a gentleman. It's too uncommon on the net, and I'm humbled. After rereading the whole thread, I can see where misunderstanding might have arisen, and I apologize as well.
I don't think it's been mentioned here, but automatic battery chargers, even automotive ones, need to sense a nominal voltage in order to detect that a battery is in the circuit. If a battery is drained below this very low level, the charger will simply refuse to do anything. Certainly there must be more and less effective tricks for refreshing batteries, but in many cases all that is happening is that some other means has been used to minimally charge them enough so that the dedicated charger recognizes them again - which, in any case, is at least better than disposing of them.
There is a debate about the range of quality right now between manufacturers - often with (the unfortunate and unavoidable) China bashing. In any case, when you send your packs off to be rebuilt, costs are kept down by using chinese cells (which may or may not be a good thing at this point in time - it keeps improving), and by using low amp/hour rated cells since many consumers pay little attention to this number. Half of the cordless tools at the store dont even list it.
Another point sometimes made is that the higher you go with the amp/hour rating of a cell the sooner you'll be developing the short circuiting links that have been mentioned here. Ahh .. trade offs. And now we have to leave all of this behind and buy Lithium Ion. I don't even own a cell phone yet!
Thank your for responding and for being such a gentleman. It's too uncommon on the net, and I'm humbled. After rereading the whole thread, I can see where misunderstanding might have arisen, and I apologize as well.
I don't think it's been mentioned here, but automatic battery chargers, even automotive ones, need to sense a nominal voltage in order to detect that a battery is in the circuit. If a battery is drained below this very low level, the charger will simply refuse to do anything. Certainly there must be more and less effective tricks for refreshing batteries, but in many cases all that is happening is that some other means has been used to minimally charge them enough so that the dedicated charger recognizes them again - which, in any case, is at least better than disposing of them.
There is a debate about the range of quality right now between manufacturers - often with (the unfortunate and unavoidable) China bashing. In any case, when you send your packs off to be rebuilt, costs are kept down by using chinese cells (which may or may not be a good thing at this point in time - it keeps improving), and by using low amp/hour rated cells since many consumers pay little attention to this number. Half of the cordless tools at the store dont even list it.
Another point sometimes made is that the higher you go with the amp/hour rating of a cell the sooner you'll be developing the short circuiting links that have been mentioned here. Ahh .. trade offs. And now we have to leave all of this behind and buy Lithium Ion. I don't even own a cell phone yet!
I fix my own batterys. Get two coils from a car and set it up so you have a comtinus arc between 2 wires. Direct the arc through the drill battery. If there is no electronics inside it will work. Call me crazy but it works, it realigns the cadium moloules and cleans the contacts inside. This process only works for nicad's with no electronics inside, which is most power tools.
edit: Leave it going about 3-4 min
edit: Leave it going about 3-4 min
Went with these...
Panasonic Sub-C 1.2V/3000mAh NiMH Cell (flattop w/tabs) $3.00
at...
http://www.nicdladyonline.com/specials.html
By far the best deal on the net that I could find. Very helpful phone help desk. Quick delivery. Soldered the tabs, reassembled, charged em up -- runs beautifully.
Panasonic Sub-C 1.2V/3000mAh NiMH Cell (flattop w/tabs) $3.00
at...
http://www.nicdladyonline.com/specials.html
By far the best deal on the net that I could find. Very helpful phone help desk. Quick delivery. Soldered the tabs, reassembled, charged em up -- runs beautifully.
Ni-Cd cell rejuvenation
the "zapper" removes shorts (should do it to each cell separately), then the process is to run the battery through several complete charge/discharge cycles, with the discharge current high enough to generate a good amount of internal heat. this removes the "memory" effect of the battery.
the "zapper" removes shorts (should do it to each cell separately), then the process is to run the battery through several complete charge/discharge cycles, with the discharge current high enough to generate a good amount of internal heat. this removes the "memory" effect of the battery.
Mains Supply Source
Am new to this forum. Came across it while doing an internet search for some sort of "gizmo" that could rejuvinate my Milwaukee 18V NiCad batteries.
I read the information that "Ashok" had posted about a zapper, showing a schematic. My question is, "What is the voltage value for the "Mains input" on the schematic.
I know that post is several years old. But hopefully someone will have the answer. Also, does each cell within the batter pack have to be zapped individually. Or can I zap the entire battery pack at once?
Thanks for any help.
skiperoo
Am new to this forum. Came across it while doing an internet search for some sort of "gizmo" that could rejuvinate my Milwaukee 18V NiCad batteries.
I read the information that "Ashok" had posted about a zapper, showing a schematic. My question is, "What is the voltage value for the "Mains input" on the schematic.
I know that post is several years old. But hopefully someone will have the answer. Also, does each cell within the batter pack have to be zapped individually. Or can I zap the entire battery pack at once?
Thanks for any help.
skiperoo
2 clues, he's half wave rectifying and getting 240V across the cap, and the other clue is he says "mains"......... he's talking 220V
you will probably have to zap it cell by cell. i've seen other zappers that use 40VDC across the cap. all you are looking for is a current spike that will burn open the nickel needles that form and short cells
you will probably have to zap it cell by cell. i've seen other zappers that use 40VDC across the cap. all you are looking for is a current spike that will burn open the nickel needles that form and short cells
Hi Skiperoo, Unclejed has given you the answers.
It is half wave rectified but the capacitor will charge up to the peak mains voltage which is 1.414xVmains rms.
So 230 volts ( here ) will charge the capacitor to just about 325 volts dc.
With a 110 V mains voltage you will get about 150 Volts across the capacitor.
You cannot zap the batteries in series because only one battery might open a short and the others will remain shorted. There could be many shorts in a battery and that can take several zaps to clear.
You need enough energy to burn the short completely. With a lower voltage you will need to increase capacitance to equal the energy storage.
With 325 volts the system uses a 32uF/450 volt capacitor. So for the same energy storage you will need a 220uF / 200volt capacitor to use on a 110 volt supply. Additionally the resistor in series used for charging is also used for discharging. I'm not sure if this is a good idea as it keeps the peak discharge current low ( about 47mA). But it must have been researched well before the circuit was published.Here it is 6.8K. You may have to drop it to 3.3K to ensure a similar discharge peak current.Everything else stays the same.
I can't find my unit right now. However I will search it out and check it again.
There are many ways to improve this zapper. A time controlled ( or counter controlled ) unit could do several zaps each time it is activated . It's been on my mind but there is a lack of time to implement it !
Cheers.
Edit. I need to check my old unit to see if the discharge section actually has the 6.8K in series . It certainly is in series with the capacitor in the charge up section.
I see people using other schemes with lower voltages where the discharge currents are very high AND apparently longer duration.
May not be good for the innards of the battery !
It is half wave rectified but the capacitor will charge up to the peak mains voltage which is 1.414xVmains rms.
So 230 volts ( here ) will charge the capacitor to just about 325 volts dc.
With a 110 V mains voltage you will get about 150 Volts across the capacitor.
You cannot zap the batteries in series because only one battery might open a short and the others will remain shorted. There could be many shorts in a battery and that can take several zaps to clear.
You need enough energy to burn the short completely. With a lower voltage you will need to increase capacitance to equal the energy storage.
With 325 volts the system uses a 32uF/450 volt capacitor. So for the same energy storage you will need a 220uF / 200volt capacitor to use on a 110 volt supply. Additionally the resistor in series used for charging is also used for discharging. I'm not sure if this is a good idea as it keeps the peak discharge current low ( about 47mA). But it must have been researched well before the circuit was published.Here it is 6.8K. You may have to drop it to 3.3K to ensure a similar discharge peak current.Everything else stays the same.
I can't find my unit right now. However I will search it out and check it again.
There are many ways to improve this zapper. A time controlled ( or counter controlled ) unit could do several zaps each time it is activated . It's been on my mind but there is a lack of time to implement it !
Cheers.
Edit. I need to check my old unit to see if the discharge section actually has the 6.8K in series . It certainly is in series with the capacitor in the charge up section.
I see people using other schemes with lower voltages where the discharge currents are very high AND apparently longer duration.
May not be good for the innards of the battery !
Stick Them in The Freezer
I read somewhere that if you freeze NiCads it will do the same trick. So I gave it a go and forgot to take them out of the freezer and then went away. Was gone for a couple of weeks. Had to let the ice melt in the sun and dry them out a bit but after that I recharged them and it worked. Got around another 20-30 charges out of them before I finally replaced them.
col.
I read somewhere that if you freeze NiCads it will do the same trick. So I gave it a go and forgot to take them out of the freezer and then went away. Was gone for a couple of weeks. Had to let the ice melt in the sun and dry them out a bit but after that I recharged them and it worked. Got around another 20-30 charges out of them before I finally replaced them.
col.
A simple multiple burst zapper.
I came up with a very simple circuit yesterday.Something that uses very few parts but needs careful handling.
One must be sure of not handling it when plugged in.
Some sections are incomplete. The charging cap needs a bleeder resistance with an led to indicate when it is discharged ( and safe to touch ). The battery is no longer grounded at one end.
It generates pulses with each mains cycle and so at 60 Hz it will give 60 pulses per second. Pulse duration is very short. Current peaks are close to 9 amps controlled by the 33 ohm resistor. Making it larger will reduce the discharge pulse current. Pulse voltage will be quite high. Over 100 volts.
I haven't tried this yet but will probably do it very soon.
Edit : The mains supply shown is wrong. It is 120 V/ 60 Hz and not 230 V !
For 230 V /50 Hz the gate trigger circuit will need R4 to be altered to 22K.
I came up with a very simple circuit yesterday.Something that uses very few parts but needs careful handling.
One must be sure of not handling it when plugged in.
Some sections are incomplete. The charging cap needs a bleeder resistance with an led to indicate when it is discharged ( and safe to touch ). The battery is no longer grounded at one end.
It generates pulses with each mains cycle and so at 60 Hz it will give 60 pulses per second. Pulse duration is very short. Current peaks are close to 9 amps controlled by the 33 ohm resistor. Making it larger will reduce the discharge pulse current. Pulse voltage will be quite high. Over 100 volts.
I haven't tried this yet but will probably do it very soon.
Edit : The mains supply shown is wrong. It is 120 V/ 60 Hz and not 230 V !
For 230 V /50 Hz the gate trigger circuit will need R4 to be altered to 22K.
Attachments
The problem I have with my rechargeable drill is that the battery is always dead when I want to use it. I only use it maybe 1x per month. It seems to take a charge when I plug it in, but I need to anticipate that I need to use it about 5-6 hours ahead of time - which never happens.
My rechargeable screwdriver is always plugged in at the workbench and seems to hold a charge nicely and not die. This has been going for several years now in this fashion.
So, should I keep my drill battery perpetually pluigged intot he charger for the 1x per month that I seem to need it? This doesn't seem like a reasonable alternative to me.
Bob
My rechargeable screwdriver is always plugged in at the workbench and seems to hold a charge nicely and not die. This has been going for several years now in this fashion.
So, should I keep my drill battery perpetually pluigged intot he charger for the 1x per month that I seem to need it? This doesn't seem like a reasonable alternative to me.
Bob
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