How to rebuild cordless drill battery packs best?
Cordless drill batteries are a topic that could make for a decent sized book! To keep this reply shorter(but it's still long!)I would like to make it clear that I am speaking ONLY of Ni-Cads; trying some of these things with other batteries and cells can result in an explosion right in your face. We need to begin with the basics. A battery is simply a group of individual cells; please keep this in mind as we go along. A Ni-Cad cell likes to be discharged fairly deeply before charging, but a Ni-Cad battery does not. With any battery, one or more cells will be weaker than the rest and overuse can reverse-charge one or more cells which cannot be corrected. This is caused by the stronger current running through a weak cell while it can no longer add to the current; therefore the current flow in that cell will be going backwards. With a Ni-Cad battery, charge it when performance just begins to fall off and it will last a lot longer. Heat also kills Ni-Cads so don't run the battery hot and let it cool before charging it. I've had some of my batteries last over 6 years in almost daily use because I follow those rules no matter what!
Ni-Cads of any given size differ. Most cordless packs consist of a number of 1.2 volt cells in a size known as "Sub C", because they are slightly smaller than an ordinary "C" cell. Their capacity varies from 600ma to over 1400ma and the price follows. In the name-brand packs you'll find cells(usually unmarked)that run to the higher end of the scale. The "Harbor Freight" etal packs use lower capacity cells. Quality of the cells varies too, with some designed to be rapid-charged while the cheaper ones unable to withstand that high rate of charge for long(if at all). Again, the name brands(DeWalt, Milwaukee, Craftsman, Ryobi, etc)are rapid-chargers, the cheaper ones aren't. Ni-Cads are all better off with a slow charging cycle but there's not much loss with the rapid-charge type and the time difference(1 hour vs 5+ hours)makes them worthwhile. Chargers also differ. While some will adapt to charging a lesser than intended capacity, others will just overcharge the cheap cells and ruin thewm. While the cheap cells can be used to rebuild a battery, you won't be getting the same performance that a new pack will give. It may be good enough if your application is medium duty, but heavy usage will show this to be true. I know because I have rebuilt dozens of batteries and I run them hard at work every day. My tools and batteries have a hard life keeping up with me!
One of the characteristics of a Ni-Cad cell is a tendency to create "dendrites", which are tiny build-ups of metallic particles inside the cell which effectively create a short circuit that gets worse with time. Excessive charging or discharging(especially the cheap cells)aggravates the situation. Dendrites can be burned off by 'flashing' a higher voltsge and current across the cell. This is the 'repair' method you hear so much of and it works for this condition. Observe correct polarity and use a car battery but don't apply the current for long, just a few brushes like you're striking a match. Too long and the cell can explode. Remember we're talking cells, not the entire battery, and each cell must be flashed indivudially. And keep your distance and sparks far from the hydrogen at the car battery; remember the Hindenburg? Nuff said!
Which brings us to the actual repairing and rebuilding of Ni-Cad packs. If you have one or two bad cells you can replace them with like cells from another old pack, thus restoring it. If several are bad replace them all(saving the good ones for the above purpose later on if you wish). From the factory most power tool batteries are connected through stainless steel ribbons which are spot-welded on. This is done as overheating a cell will ruin it or cause it to explode. The spotwelding is done so rapidly no heat buildup occurs. Soldering is possible here but it takes a lot of heat applied quickly and removed quickly, as well as a good flux. Roughening the surfaces with sandpaper seems to help. As a Ham radio nut I've soldered extensively and this is the toughest soldering job I know of. The internet has plans for making your own spot welder but I haven't built one so you're on your own there. The specialized spot welders for batteries cost more than you're going to want to pay!
Now the good part: Replacement cells can be had with tabs already spot welded on and these tabs are very solderable so use them only. You'll be glad you did! Buy the best cells you can find, again the extra quality is well worth the cost. The downside is that you're probably going to spend nearly as much(or even more!)than a new or factory rebuilt pack. Sorry for that bad news and if you know of a good source for quality cells cheap please let me know! I cheat-I buy new Craftsman packs at K-Mart(much cheaper than at Sears and nearly top-of-the-line cells)and use those for my rebuilds. I've bought a new 19.2 volter there for $19.99 on sale. My last 18V batch of Sub-C NiCads cost me $62 after shipping and were a lesser capacity to boot.
By studying the way the battery goes together you can usually cut the Craftsman apart in a way that minimizes the soldering you'll need to do. If you have space you can even take off the positive or negative connection(according to the battery you're working on)from a different place. All that matters is that all cells are in series, that the new take-off point goes to the right connector in the pack case, and that you're added connection can handle the current. If I'm out of copper ribbon(which I make from the gutter man's scraps)I use 12ga stranded wire if I can fit it. However you do it, be certain that a short circuit is impossible or you'll find yourself with a fire at best or an explosion at worst, not to mention the melted plastic all over everything(hopefully not your charger where a short will usually occur). If you use plastic to insulate be sure it can handle a lot of heat; I like to use the heavy cardboard from a notepad back. So long as it's kept dry it makes a great insulator but it will ignite easily if a short heats things up.
Sorry for the long reply but like I said, there's a lot more to cordless drill batteries that meets the eye and we haven't even touched on the Nimh's or the Lithiums! If the subject intrigues you check out the technical forums at www.all-battery.com
You might even luck out and find a good deal on the replacement pack you need there. I've used them several times and I can reccomend them but they don't carry as extensive a line of replacement packs as they used to.
How to pick the right drills for the right job
You must ascertain before purchasing DeWALT Cordless Drills the purpose you want to use them, do you want cordless drill drivers to drill holes & drive screws or would you prefer cordless hammer drills with built-in screwdriver & drilling options? Many people buy Makita Cordless Drills for one purpose only and then subsequently find they need the advanced version, this is where specialists like Power-Tools-Pro come into our own having the necessary machine knowledge to assist you make the right purchase for specific and general applications. To conclude always research the various Cordless Drills we offer and always check the specification carefully, check for any accessories you need like screwdriver bits to enhance the use of any of your Bosch Cordless Drills, make sure you always seek a specialist supplier for power tool requirements talk to us Power-Tools-Pro - top tools for the trade
Of course,choice the best cordless drills the we must choice the compatible cordless drill battery for our needs.we can recommend an online shop www.battery-replacmenet.org/cordless-drill-batteries.html choose the right battery for you.
What i asking is the cordless drill batteries mentioned all fit the same charger they are all the same brand and type, so what does (Ah) mean
Can a cordless drill battery 7.2v/1.4Ah use a 7.2v/1.5Ah battery or even 7.2v/1.2Ah without damaging the power too.What i asking is the cordless drill batteries mentioned all fit the same charger they are all the same brand and type, so what does (Ah) mean?
Ah is the "Ampere Hour" rating of the battery. It's a measure of how much current (amps) can be drawn from the battery for a period of time (hours). So a 1.5Ah rated battery would provide .3A for 5 hours, .5 A for 3 hours, or 1.5A for one hour. While it is important that the Voltage rating matches (7.2V),the Amp-Hour rating indicates the relative capacity of the rechargeable battery - with a higher number being better. The batteries you have should be interchangeable.
If your power tool draws .7A under normal use, the 1.4Ah battery would last about 2 hours. The 1.5Ah battery would last maybe a few minutes longer. If your tool draws 1.5A, then both batteries would last about an hour.Since batteries vary, the Ah rating is only an estimate under typical conditions. My guess is that you would not see much difference between a 1.2Ah, 1.4Ah, and 1.5Ah battery in a typical power tool.
See the section on battery capacity in the Wikipedia link below for more info. The second link below is for two replacement batteries for the same 7.2v cordless drill. Both are listed as a 1.3Ah battery, even though one is actually 1500mAh (1.5Ah) and the other is 1700mAh (1.7Ah). They are interchangeable. Both should last longer than the original, and the 1700mAh battery should last about 10-15% longer than the 1500mAh battery.
Cordless drill battery power supply
NiCd and NiMH cordless drill batteries (commonly used in drills) when fully charged are between 10 and 15% over 'nominal' voltage. Your 18V pack will quite reasonably be up to 21V when fresh off the charger; your cordless drill should be able to safely deal with 20V, though it might overheat more rapidly if you provided it with a 20V supply.
As GWIZ mentions, we don't know what the drill pulls. Most cordless drill battery cells are capable of '10C' discharge, meaning that if the cell is rated at 2000mAh, the cell is capable of safely being used at 10 x 2000mA = 20A. Your drill could conceivably use up to 20A, though it probably uses less. Under load, the voltage of the battery will drop, so that same pack which measures 20V fresh off the charger, might measure 16V under a 10A load.
What you need to do is to find a power supply which can provide the full current required by the drill, with a voltage that sags roughly the same as the battery pack under the same load.
I would start by borrowing a good 'lab' power supply, one that lets you adjust its output voltage and which measures its output current. You would need something capable of at least 20V and 10A, possibly more. Then use this power supply to run the drill, determining how much current is required under full load (the largest drilling load that you are going to use). In particular, experiment with letting the voltage 'sag', say by adjusting the supply for 16V, and trying the drill out running a load, to see if the performance is sufficient and to see what the current requirements are. After some time playing with the system, you will end up with a specification for 'I need an '18V' power supply battery pack with a maximum unloaded voltage of A (probably about 20V), a maximum current capability of B (5-20A), and a minimum voltage under full load of C (15-18V).'
Dewalt cordless drill battery charger will not allow the battery to charge
When I place the 9V Sears dewalt cordless drill battery into the charger the evaluating light stays on and the battery will not take a charge. If I lift the battery out of the hole just a little bit and the evaluating light does not go on then the battery will charge. The problem is that the battery needs to be propped up very carefully and a spacer added to keep the battery from falling completely into the hole and this takes just the right tough. Many times I return to check the battery and the eval light is on and no charge. So I start again. Can the eval system be disabled?
I don't know if the evaluation system can be disabled or not, but if it's still in warranty you will certainly disable that if you take it apart. If it's not in warranty any more, then given the amount of trouble you have getting it to charge I'd certainly take it apart and try cutting the lines that go to the light. Maybe they are the ones that run the eval. system. Be careful when you do cut them as you could probably hook them back up if that isn't what you need done. In the meanwhile you could start watching on www.battery-replacement.org for a replacement battery charger. They can usually be had fairly cheap. And as a last resort, you could do as I do with my 12 volt batteries. I simply attach, usually by clamp, a couple of small bolts, to the contacts for charging the batt's, and then hook up my 12 volt car battery charger. 12 volts is 12 volts, no matter what charger is delivering it, so this works just fine. I've gone through several chargers that came with different battery tools, and I'm still charging the batteries with a car charger that I've had for over 10 years. The fact that it's 12 volts, simply means that the batteries will charge faster than the regular 9 volt charger. You'll have to keep an eye on them. I'd try 20 min's. as a place to start, if they don't seem charged enough at that, make the next charge a little longer, maybe 30 min's. Eventually you'll find the right combination.
Maybe I can Unplug the charger. Use rubbing alcohol and clean the contacts on the battery and charger. Does it happen with both batteries? If so then you probably have a bad charger. If its just one battery then that battery is bad. There isn't any way to disable the evaluation process most chargers check the battery when you first insert it
Load cordless drill battery best
How to load cordless drill battery if it have only two outputs (plus and minus), but charger have three ( plus, minus and loading level check)? Can i somehow trick charger to load this battery. Now when i connect only two connections (plus and minus), my baterry down't loads.Charger have two leds (one green and one red), only green lights, but red down't.
The third connection on the battery will be a temperature sensor to detect when the battery is charged. Maybe its Foked.
Sounds like the battery is not matched to the charger and you cannot use that charger to charge it. Did the battery come with the drill, or is it some off-brand replacement? Solution for someone with time on their hands and knowledge of electronics would be to rebuild the charger to use dV/dt to detect end-of-charge, but I wouldn't recommend that if you don't already understand about drill battery charging. I would recommend getting the right battery for the charger, or the right charger for the battery. If someone sold you the battery as being compatible, you should complain.
14.4V Drill battery pack alternative
This one from my son, who found the idea on another board.When the 14.4v battery drill pack dies and will not hold a charge for your 14.4v cordless tools try this:
Take the dead battery pack apart and toss the cells.Take an extension cord and remove both ends (male & female) from the cord.Solder the extension cord wires to the contacts inside the battery pack.Drill a hole in the base of the pack and run the extension cord through the hole.Get a pair of battery charger alligator clamps and attach them to the other end of the cord.Important: Be sure you put the red clip on the wire that is connected to the terminal inside the old battery pack and the black clip on the terminal wire.
Now, whenever you are working on your car, your 14.4v drill/sander etc, etc has a power supply, by simply attaching the clips to your car battery. Especially good for "on the road" repairs, etc,You don't have to worry about the battery pack going dead, or the lack of a 120v outlet on the road,you lose the "cordless" feature, but you gain a reliable tool to take along on a trip!(and you can still use the drill as a cordless by putting your other 14.4v (working) battery pack in it for "around the house" work).
Why not just rebuild the battery pack? All it takes for most is a handful of sub-C cells, a soldering iron and a half hour (after the first one - to figure out how they are 'wired'). And yes, several of the guys here "taught" me how and it works great - unfortunately, the Porter Cable drill I did it for blew the clutch, so now I have a new Bosch drill - which isn't quite as good.And to rebuild a battery pack, you don't even need (or want, for that matter) the high-dollar fast dump high performance RC batteries, the plain vanilla's work fine.
Cordless drill battery hold a charge
I have 3 black craftsman 12v drills (had one before I married, my husband had one already and we have a swivel head one too). I have a brand new battery (bought yesterday) as well as 3 older cordless drill batteries. I have 3 chargers total and not one of them will charge the batteries (new or old ones) adequately enough to drill even one hole in my cabinet. I have even tried charging them overnight. Two chargers are the type that plug into the drill itself when the battery is attached. The other charger is separate from the drill and holds a single battery pack. The separate charging pack has a red light on it but it does not light up. I have plugged them into multiple different a/c outlets.
It sounds like your chargers are shot. The ones that come with the drills aren't very good and don't last. B&D sells a multi-volt charger which is much better made than the ones that come with the drills. Can't remember what its voltage range is but it works on my 14.4 volt drill batteries.
I bought the charger you are talking about. It charges 9-18V batteries. It also tests the batteries to see if they are defective/too old to hold a charge. All of my batteries are good but my 3 chargers are bad. The new charger not only charges my drill batteries but my 18V outside ones too.
As it happens, pretty much every battery does have some spontaneous discharge rate although NiCds are better than others this way, so it is best to anticipate that condition and plan to charge your batteries before each use.
NiCd batteries need to be fully cycled or they will develop a memory. Lithium batteries may be short-cycled but do have a spontaneous discharge rate of a few percent per day and so will eventually drain completely even 'just sitting there' - but may be recharged or left on the trickle-charger indefinitely.
Can I wire the contacts from the charger directly to the switch on the drill to bypass the battery
I'm going to be using the motor from a cordless power drill for a home theatre project (remote-controlled rotating TV), but I would much rather have constant power supply and not have to mess with the cordless drill batteries. The reason I am using a cordless drill is for the 2-speed gearbox (i need low rpm w/ more torque) and the autobrake. My question is this:Can I wire the contacts from the charger directly to the switch on the drill to bypass the battery? If not, what would be the problem/result of this? How can I make this work?
The cordless drill battery service cener answer me:Chargers are current regulated at a safe level designed for the battery. As such, it is not sufficient to run the motor directly, especially under load. A better solution is to find or build a suitable power supply. I would think something with a couple of amps should put you in the game. If you build it, it would only take 3 basic parts -a transformer (with a secondary close to the voltage and current you need), a bridge rectifier, and a modest electrolytic filter capacitor.As to wiring, the power supply should be hooked to the leads of the battery contacts. The leads of the drill's switch would be hooked to whatever actuator you are using with your remote.
I once played with a battery drill - hooked it up to a 12V drill battery for mobile use - and measured about 9A while drilling an 8mm hole into aluminium. You could measure this (best to measure under load, so do it once it's installed and working),You could leave the battery in circuit by connecting the charger to the battery contacts while the battery is in the drill. The drill battery would always receive a charge and would supply the larger current when the unit is occasionally activated. Depending on the quality of your charger, this may cause the battery and charger to get warm, maybe even overcharge the battery. If so, make sure you can switch the charger off; I doubt you'd need to switch in on very often.If all this spells a hobby in dc power, the concept of storage for short term peak loads will be well demonstrated. If not, your theatre will look good anyway.
Cordless Drill Battery Option
I have a Craftsman cordless drill and flashlight that uses 16.8V Ni-Cd packs. The drill's about 6 years old now and the packs aren't holding a charge for very long. So i'm faced with 4 options:
a) Buy a couple new Ni-Cd packs (about $50-60 online)
b) Buy a Ni-Mh pack (about $70) but would it work with my existing charger?
c) Attempt to rebuild the pack from individual cells (looks like a pain)
d) Buy a nice new smaller/lighter drill!
The drill only sees light/medium household duty, usually not more than 15 minutes at a time. I probably use the flashlight more than the drill.
I use 18V DeWalt drills frequently, but I tend to overbuy. If you're in the market for a different drill, I know many, many construction and electrical contractors that prefer the 14.4V DeWalt stuff due to the equipment weighing less but still packing plenty of punch.
I use a Milwaukee 18V and rebuild the drill battery packs myself. It's not really a pain, but if you don't have the patience for soldering, etc. it may not be worth it.Typically a NiCd charger should work with the NiMh batteries. Mine actually says both on there, but I would imagine yours would work as well.There are third party generic battery pack makers too, that have NiMh battery packs for drills that had NiCd packs.
I opened up my pack and there are 14 cells in there, each cell looks like an odd sized battery (about 4.2 cm tall x 2.2 cm diameter, smaller than a C-size) Each tab looks like it was spot-welded too. That's why I say it looks like a pain; weird batteries and not something my soldering iron can handle!
NiCd batteries don't hold up as well to charging as NiMh batteries. But in either case it's very important not to over-charge the batteries. Many drill chargers do not automatically turn off and will all the battery to over-charge and heat up. This will significantly shorten the batteries life.Here is my 2 cents... if you have a Harbor Freight store in your area, consider buying the 18 volt drill they sell for $20-$30. My father has had his for 3 years and I've had mine for 2 years. it works perfectly and the 18 volts will get 99.99% of your jobs done (for those others, I keep a corded drill around).
They are sub-C batteries and can be bought in many places over the internet. Ebay has great pricing on them. Soldering to them isn't too hard, even though the originally connected packs may have been spot welded.I love my Milwaukee tools, but if I hadn't paid $300 for the drill and whatever amounts for the circular saw and sawzall, I'd move to Rigid brand. They warrantee their batteries as well as the tools.For your usage, I'd not even consider things in those price ranges (and weights). The HF suggestion is a good one I think for light duty usage.
I have a Panasonic that is over 8 years old. It's a great drill. Small, light, and great torque for it's size (excellent for cabinetry work, lightweight so no fatigue with overhead drilling/screw work). But needing a battery, the new replacement was $90 shy of a new drill with two batteries and charger! Eventually, I found a replacement battery for $45. But had I not, I would have bought a new drill/driver. Which is too bad as the screwgun still goes and
goes.
If you have any question about cordless drill batteries,you can feel free to contact me,i will do my best for everybody.