Lithium Ion vs. Ni-Mh vs. Ni-Cad?

[krogers]

I am considering an upgrade to my cordless. I read a couple of recent threads on the cordless purchases, but I didn't want to hijack another thread. I have a 9.6v makita 9063DW that was originally purchased in 1988. And I can say that it has been a great performing drill. I have been through a few batteries in two decades. But other than that is has been a solid performer. I am considering a move up to a 12v or 14v. If I am satisfied with 9.6 I think 14 will be a great improvement. I don't want the weight of 18v. So a couple of questions? I definitley want a Hammer Drill and an Impact Driver. I wouldn't mind a sawsall in the future. I can't find a combo kit with just those tools. (and maybe a flashlight.) So it seems that Dewalt 14v is the way to go? They offer all those tools in 14. Haven't seen them in 12v. Has anyone tried out the new Makita lithium ion tools? Should I go for 18v power at 12v weight? I know they are pricey, but I have had a great experience with my original Makita. So while I am now just a weekend warrior, this quality tool might last for another twenty years. Yes, I read the FW article on Li tools and batteries. I am just wondering if it is worth pulling the trigger. Maybe I should go with a 14v Makita Ni-mh and save a few dollars?

[skruffy]

The new Makitas are fantastic. Though I've only used the hammer drill and impact driver briefly, they are full of power, comfortable in the hand (mine anyway) and light. I had convinced myself I was going to shell out the money because with the rebate promo you can get both of them for about $280.

Then I did some research on lithium ion batteries, and I changed my mind. I don't remember the URLs that i found, but they all seemed to indicate that the batteries lose capacity based on how old they are (when they were made), not based on how they are used and charged. To me they seemd great for a professional that uses them all the time, but not worth the investment for someone that uses them less seriously.

In the end, I bought a 12 volt DeWalt impact driver to share batteries with my drill that needed batteries. The DeWalt impact actually has a bit more torque than the Makita (1400 vs 1280) and also fits my hand well, but it defintely isn't as "cool".

[krogers]

Any more experience?

I am still working on this decision. Has anyone else had any more experience with any of the Lithium Ion tools? My biggest concern is the weight. I want a light tool for driving screws most of the time. It's seems that an ID will be about the same weight as my current drill/driver. And I want a hammer drill that shares the same battery. The only options seem to be a 14v Dewalt set or the Makita 18v li-ion.

[Hellrazor]

I can't give you a direct recommendation for what you are looking at. I am a heavy duty user of tools both at my job and at home. I have 3 drills I regularly use at work 1. Dewalt 12v 2. Skil 14v 3. Milwaukee 18v hammer drill. The Dewalt performs worse than the Skil and the 18v hammer is heavy.

At home I have a crapload of Ridgids I use: Hammer Drill, Drill, Impact, Reciprocating saw, Jigsaw, circsaw, 2 chargers, 6 18v batteries and a light. I am more than happy with the Ridgid tools. But as you mentioned the 18v weight is a pain. I also have one old 9.6/12v Makita drill.

My take on power tools and how I would rate them is:

1. Ridgid & Milwaukee
2. Makita
3. Dewalt
...
100. Craftsman

Also things to watch out for, check battery charge times. I am spoiled with the 30m charges on the Ridgids since alot are 1hour.

[vaking]

I don't know about Ni-MH batteries in tools but I had experience with them in PDAs and laptops. Those batteries last for 1 year whether you use or not. After a year the battery is dead and you need a new one. The PDA battery of that kind goes for about $100, what do you think a tool battery will be?

[RodKirby]

Funny how someone on this forum seems to post about something that is "current" for me!

I have loved my 9.6 DeWalt drill for around 4 years - and then I went to our annual WW Show... Was walking past the Panasonic stand and picked up their VERY NEW 14.4 Li-ion Drill - WOW 1/2 LB lighter (and much smaller), than the DeWalt and 1,350RPM, 1/2" chuck, heaps of torque - couldn't resist. 2 batteries and a "weird" 1 hour charger. for about US$440 - yeah I know - but...

BTW it also comes in an impact version - sounds like a jack-hammer, but drives 3" screws into hardwood like you wouldn't believe!

What I like:

• The (lack of) weight - very easy to handle.
• The fast 1,350RPM - great drilling in soft wood.
• The Panasonic version of the quick change bit holder - inserted drill bits don't flop around as much as others.
• The way the Li-ion batteries hold their charge even if unused for days.

Time will tell if the batteries last. Not yet shown anywhere (that I could find) on the net.

[krogers]

Rod, I have looked at the 'old' Panasonic due to the excellent reviews that it receives. IIRC it was the top performer in one of the mag tool tests for driving the most long screws. My concern has always been that Panasonic only offered a drill. A one tool solution. I have always been happy with the idea of multiple tools that can run on one set of batteries. Currently I only have the drill, a small trim saw (4" circular) and a flashlight. I will have to take a look at the 'new' Panasonic you are referencing. But I would really like the option of an ID, work light, and maybe a reciprocating saw.

I am now just a weekend warrior, but I have had a eighteen years of success with my first tool by buying professional grade. So I don't mind paying for that category again. I just don't want a tool that heavier than I currently have. I will never need an 18v tool for constant/daily use. 14v seems like overkill for my needs, but it seems to be the lowest voltage with a hammer drill. I don't own a hammerdrill now. Have infrequent need for one, but figure is I am buying a drill I should get the feature. (I have only bought one cordless drill and one corded drill in two decades.)

[Hellrazor]

BTW.. A hammerdrill is going to weigh more than a drill. If you want a hammerdrill for very infrequent use, get one of those cheapy harbor frieght corded ones.

[jseklund]

Ok, I'm far from an expert on this, and some of this may be wrong- so take it all with a grain of salt. Hopefully it will at least tell you which roads to go down and anyone here can tell me if I'm wrong.

As far as batteries go, it seems like we are looking at 1 of 3 types in tools- Lithium Ion (Li-On), Nickel Cadmium (Ni-Cd) or Nickel Metal Hydride (Ni-Mh). The names and abbreviations may be slightly off...just going from memory, and again- I'm no expert.

So here is what I've found on a quick search of the different battery types:

Li-On
Positives: Smaller in size, lighter in weight, 1 1/2 times the energy storage of a comparable Ni-Cd, Slightly lower resistance allows it to hold a charge slightly longer, no memory effect (not sure on this one).

Negatives: More expensive, chemical reactions within the battery counter-act the lower resistance (so the longer charge hold is not quite as high as the resistance alone would lead you to believe), You get a substantially lower number of charge/discharge cycles (about 200), inability to withstand large drains (heavy duty work will kill the batter fast, if not instantly?).

Summary- Basically this battery is lighter, but will not last as long, will not provide the heavy-drain power you will need in some situations, etc. Weight/Size is the only benefit to me it seems.

Ni-Cd-
Pros-Longest shelf life and do not discharge as quickly as Li-On or Ni-MH, quickest to charge, longest lasting (500 cycles?), CHEAP!

Cons- Lowest capacity (this means you need more battery for the same power, in other words, lower capacity=heavier and bigger), Memory Effect (reduces the actual number of cycles you get if you do not completely drain/recharge battery), older technology (if this makes any real-world difference I don't know)

Summary- Ni-Cd. is a cheap battery with some great features. However, it will weigh a good bit more and has a memory effect. They will, however provide the power and last longer.

Ni-Mh-
Pros- Newer technology than Ni-Cd, NO memory effect, around 1,000 life cycles, less environmental impact than Ni-Cd, good in high-drain devices, less expensive than Li-On, holds about 2X the energy of a Ni-Cd (meaning that a smaller battery will have the same output= less size/weight than Ni-Cd).

Cons- More expensive than Ni-Cd, heavier and bigger than Li-On.

Summary- Ni-Mh seems to have gone for the middle ground. It demonstrates the longest shelf-life, has no memory effect, and works well under high-drain. However, it is not nearly as light as a Li-On.

With all of this in mind, I think the Ni-Mh would be the BEST choice for a weekend-warrior. You are not going to be hefting the tool all day long, day after day, so is a little extra weight the major concern? Or would you prefer to have the battery hold a charge the longest (since you may not pick it up again for a month after you finish using it- nothing like needing a battery when it's dead), and lasts the longest. Not to mention, if you leave a Li-On discharged long enough, it may damage the cells permanately it seems. Ni-Mh is the middle ground on weight and high ground on power, life, etc.

Having said that, which tools to go with? I agree- having the batteries work between tools is VERY nice. I just got an Impact Driver and the salesman at Western Tools Supply said the Panasonic was really the best on the market but no one noticed because it wasn't Bosch, Milwaukee, etc. I don't know if this holds true for the Hammerdrill. What I do know is that the Impact Driver was 14.4 volts and came with a 14.4V hammer drill. I have an 18V drill and they are comparable in weight if you ask me. Granted, the hammer drill in 18V may be even heavier....I don't know. These are also DeWalt tools.

If you are looking for a sawsall, I would go 18V, but that's just me. Sawsalls are very useful, and you'll want it to have plenty of power. However, since you probably will use the drill more, if weight is that important you should get the better drill and lesser sawsall. I have an 18V dewalt Sawsall/Drill (not a hammer drill) combo kit that I got for Christmas about 3 years ago that I torture and it is a GREAT little set. I know most real tool users don't seem to hold DeWalt too highly, but I've had good luck.

[Andrew Benedetto]

Ni Cad Myth

http://www.battcon.com/PapersFinal20...mory%20effect'
I wish I had a $1 for everytime the "memory effect" is mentioned.
This is a very complete paper on that myth.
BTW my LiIon dremel keeps a charge for months and is a great tool. I also have a Bosch I driver. Weight and charge life seem to be the advantages on the LiIon batts.

[os1kne]

krogers,

Much like you, I have had a 9.6v Makita for 10+ years and it still works (the clutch is starting to go). A few years ago, I was looking to get a new battery and HD had a display model 9.6v Makita with battery for $30, so I snatched it up. Last week I was at Lowe's and they were having a sidewalk clearance deal - spotted a 9.6v Makita battery for $2.

Anyway, while my 9.6v Makitas have performed admirably, I have longed for more power recently. Not sure to go with the 18v Dewalt or new Makita LiIon.

[Tom Slick]

I like the longer run time of NIMH but I think NICADs seem to have a longer shelf life. I think the switch to NIMH was generated by environmental concerns/regulations rather then performance. LION batteries to seem to be a bigger improvement then the NICAD to NIMH batteries were.

[HarmsWay]

I have a battery book (Batteries for a Portable World?? or something like that. They have different statistics many comparing the types. The book is a few years old so maybe the information is not accurate anymore.

When compared to NiCD, NiMH gives you about 30% greater capacity per volume, contains less toxic chemicals and suffers from less large crystal formation (perceived memory). That's it for the advantages though. NiMH still requires periodic exercise (once every 3 months instead of every month with NiCD). NiMH is also about 30% more expensive and requires a more complicated charger (also more $). It's optimum charge takes about twice as long (2-4 hrs instead of 1-2). But the big killer with NiMH is that it gives you about 1/3 the cycle life (about 1500 cycles for NiCD and 500 for NiMH).

To minimize crystalline formation, rechargeable batteries should be discharged regularly to less than 1 volt per cell - NiCD's once per month and NiMH once every three months. Some smart battery packs have embedded intelligence and work with their charger to do this automatically, but this is more typical for razors than power tools. If you haven't been discharging NiCD's monthly, then the crystals can build to a point where a slower deep discharge may help (cell < 0.6 volt). Another way crystals form is by self-discharging slowly over a long time. So if you don't plan on using a battery for a few months, fully charge it first, then discharge at a normal rate. The optimum charge time for NiCD batteries is 1-2 hours. Slower & faster chargers tend to heat up the batteries too much.

Lithium ion batteries have an even better power to weight ratio and cycle life at the expense of well - expense.

From what I understand, the biggest factors affecting battery life in a power tool application are prolonged high temperature during charging (either because of a high fixed rate charge or a long slow overcharge), poorly matched cells where the highest capacity cell gets all the work (in theory when you pay more for battery packs, you are paying for better cell matching), and high current discharge (as in stalling a motor).

Personally, I would stay away from NiMH unless its a business expense and time is money.

[os1kne]

One thing that I forgot to mention is that there seems to be 100 tools that will run on the 18v Dewalt NiCd batteries, far fewer for the Makita. Not that it is a big deal, but I try not to have to keep up with several battery styles and chargers, so this may have some influence.

Good luck.