Thread: NiCad vs Lithium

It depends what tool its for. You will notice a significant difference on tools that draw alot of current from the battery, eg cordless angle grinders, saws, rotary hammers

Most brands will be phasing out nicd & nimh technology so if you are buying the kit that isnt lithium ion make sure that the charger is lithium ion compatible

Nicads and NiMH batteries do not like fast charging unless there is a fair degree of sensing circuitry to establish the exact 'fully charged' point. They can cope with a fast charge while flat, but continuing a fast charge when fully charged leads to overheating and venting electrolyte, reducing the packs work capacity for evermore.

Most of the cheaper Nicad/NiMH tools targetted to DIY users have very little in the way of sensing circuitry in their charge system, but try to recharge in about an hour or so. This is a recipe for fried batteries if you don't disconnect them from the charger as soon as they are charged. Single replacement batteries or repacks often cost more than a kit including the tool, case, charger, 2 batteries and accessories.

Industrial level Nicad/NiMH tools have decent sensing in the charger and control the charge rate relative to the measured battery state, but price wise they are in a similar region to Lithium tools. Lithiums seem to maintain their oomf better than Nicad/NiMH, so managers are migrating in that direction.

As VEK suggested, it depends on the tools and the way you use them.

Sorry but lest have a reality check here.

The methods of charging nicad/ NimH are so very different to that of lithium that I find it unlikly that a manufacturer would build a product compatable with both.......although someone like festo might be crazy enough to try.

As for manufacturers phasing out NiCad & NimH......I don't see that happening any time soon.... there are so many NiCad & NimH units out there the batteries will be available for quite some time.....hell I can still get packs for my 7.2V makitas almost anywhere.

As the whole lot about fast charging NiCad / NimH.......only specific fast charge cells should be fast charged and almost all the packs you will see come with a temperiture sensor in the pack... if it has 3 terminals the third is the sensor connection.....the early packs ended charging bassed on temperature of the pack......there are a very few that use something more sofisticated.

Now if you have a Nicad or NimH battery that has vented electrolite it is buggererd, stuffed , finsihed.... problably because it has exploded...... these are " dry battery" technologies and do not have free electrolite like some other types....if there is sufficient preasure to blow the seal, it has almost certainly pushed off the terminal cap and the battery has go so hot as to be past the point of no return before that.

As for lithium ion.......An absolutely bitching battery technology... but still expensive as hell in comparison to the earlier technologies...as you have found............now lithium realy does need some very serious charging controll.....if they are not properly controlled they go into thermal runaway and go up in flames or explode or both......there have been a couple of very well publicised recalls... one on a very very popular laptop computer and a couple of mobile phones.

lithium is very much lighter and higher energy density that almost all other technologies .... but there is no free lunch.

Now there is one thing I dont get.....is these " handy and convieninient" powertools with huge batteries......24 volt............. hell you have to be a strong man just to pick it up..........don't be so damn lazy...... just run out an extension cord.

Or buy a generator and use a real powertool.

My old 7.2 volt makitas still do the job for me......yeh some new 9.6's would be better....and I can see that 12 volt would be reasonable... but 24V.... Naaa.

cheers

I agree with Soundman. All of my cordless drills and impact drivers are 12V NiCads'.
I have some dead battery packs that I pulled apart and put some cable on and then I can use them on a car battery if necessary (when all other battery packs are recharging). This is usually in the workshop. Otherwise I used corded tools.

Originally Posted by soundman

Sorry but lest have a reality check here.

.... Naaa.

cheers

While I agree with most of what you write, Soundman, and I think you make a lot of sense, why is it that my mind automatically converts your words into the spoken voice of the comic store guy from the Simpsons?

Originally Posted by Rossluck

While I agree with most of what you write, Soundman, and I think you make a lot of sense, why is it that my mind automatically converts your words into the spoken voice of the comic store guy from the Simpsons?

A very good question.......But only you can understand the twisted workings of your own mind

cheers

Originally Posted by soundman

A very good question.......But only you can understand the twisted workings of your own mind

cheers

You're so right.

Originally Posted by soundman

Sorry but lest have a reality check here.

The methods of charging nicad/ NimH are so very different to that of lithium that I find it unlikly that a manufacturer would build a product compatable with both.......although someone like festo might be crazy enough to try.

Makita XLT chargers are dual Li Ion/Nicad compatable, and cover the voltage range from 7.2 V to 18V. As supplied with the Li Ion kits they require a plastic shoe (adaptor) for Nicad operation, readily available in US. Haven't had a look at one (adaptor) so I don't know if they are active or passive. Replacement chargers are in the order of US$100.

As for manufacturers phasing out NiCad & NimH......I don't see that happening any time soon.... there are so many NiCad & NimH units out there the batteries will be available for quite some time.....hell I can still get packs for my 7.2V makitas almost anywhere.

Cheap Nicad cells will probably be around for quite some time, but for the most part aftermarket suppliers and customers try to source cheaper inferior cells that don't have the life or fast charge capacity. The last time I looked for original replacement packs for a Ryobi 12 V drill, they were over A$110 each, when the drill kit was A$89 with two battery packs 18 months before. On the other hand genuine Mak Li Ion 18V 3AH packs are US$99 for about triple the storage density.


As the whole lot about fast charging NiCad / NimH.......only specific fast charge cells should be fast charged and almost all the packs you will see come with a temperiture sensor in the pack... if it has 3 terminals the third is the sensor connection.....the early packs ended charging bassed on temperature of the pack......there are a very few that use something more sofisticated.

Just the point I was trying to make about Nicads, special cells and sophisticated chargers are required for successfull fast charge operation. Most of the DIY range tools that I have seen (Ryobi, GMC etc) came with a plug pack charger and a two contact connector, no temp sensing or delta peak sensing there. It's there on some of the higher level tools like AEG etc, but the cost is getting into the region of the LI Ion systems. Then again, temp sensing is a secondary indication of charge completion, not a primary one like delta peak voltage sensing.

Now if you have a Nicad or NimH battery that has vented electrolite it is buggererd, stuffed , finsihed.... problably because it has exploded...... these are " dry battery" technologies and do not have free electrolite like some other types....if there is sufficient preasure to blow the seal, it has almost certainly pushed off the terminal cap and the battery has go so hot as to be past the point of no return before that.

All Nicads except button cells have a pressure relief valve built into them below the cap, and a pin hole in the cap, specifically for releasing pressure which builds up if the cell is overheated. Electrolyte is a moist paste. The moisture begins to evaporate from the electrolyte when overheated and increases internal cell pressure until the point where the relief valve vents the gasses to the atmosphere (or battery case). If the cell vents once it is reducing it's capacity and increasing the chances that it will overcharge/overheat/vent again.

As for lithium ion.......An absolutely bitching battery technology... but still expensive as hell in comparison to the earlier technologies...as you have found............now lithium realy does need some very serious charging controll.....if they are not properly controlled they go into thermal runaway and go up in flames or explode or both......there have been a couple of very well publicised recalls... one on a very very popular laptop computer and a couple of mobile phones.

The Mak Li Ion chargers have a number of features, including a cool down phase for packs that have heated up while running a tool, fan cooling and temp monitoring of the battery during charging, thermal charge current control, individual cell charge balancing and conditioning, and the battery packs each have their own inbuilt microprocessor to record charge and discharge situation data and make it available to the charger for optimal charging.

lithium is very much lighter and higher energy density that almost all other technologies .... but there is no free lunch.

Now there is one thing I dont get.....is these " handy and convieninient" powertools with huge batteries......24 volt............. hell you have to be a strong man just to pick it up..........don't be so damn lazy...... just run out an extension cord.

Totally agreed


cheers

I have refered to the Mak Li Ion system because that is what I bought into a couple of years ago, and so I have some knowledge of its care and feeding. As an Electronic Engineer with experience in designing, manufacturing and supporting Nicad fast chargers in the past, I also have a fair idea of their charge requirements, both slow charging and fast charging.

Yeh so, you have found a manufacturer who has a charger that charges both.....it hardly makes a valid recomendation that anyone buying should buy a charger that does both.... becauise it would not be very uncommon.
Consider also....that a charger that is sofisticate enough to charge lithium could be easily adapted to charge Nicad or NimH.... perhaps a softwere switch in the microprocessor that they all seem to need

Oh BTW.... lets not worry too much about what is available in US dollars because most people here will be buying a 240volt supplied charger and paying Australian dollars.

As for replacement batteries..... all the cheaper units and many of the mid range units come with batteries and replacement batteries on the cheaper units are very expensive in relationship to the origianl purchase price..... this is not news.

God quality NiCad and NimH batteries and battery packs will be arround for quite some time...... for very good reason...... Nicad and its derivative NimH are very good technologies and have some very valuable technical advantages additianlay they will always be significantly cheaper than lithium.

Consider that almost all powertool batter packs are built up from one single cell format "SUB C", and almost all of the fast charge packs use one of 3 temperature sensors.... even the terminals used are common between many packs and brands...It is very easy to continue with the scales of economy, as all that is needed is a plastic moulding for each pack

As for replacement battery packs.....most of the replacement battery packs I have been offered are built on Sanyo cadnica fast charge cells.... sanyo have had the fast charge Nicad market by the balls for decades.... they simply make the best fast charge nicad product and at a reasonable price.... most of the reputable brand OEM packs are built on sanyo batteries.

Further.....many of the genuine brand packs are available in upgraded capacity likewise the generic replacements

The fast charge cells are not realy anything special... they are a little more expensive, but are very redily avaialble from the right sources and charging them effectively requires very little in the way of technology if a 1 hour charge is acceptable......a source of supply witha voltage signoficatly greater than the pack voltage, a current limiting circuit ( thus far standard NiCad or NimH charging) and a temperature switch bonded to a battery inside the pack.... oh and a latching circiut with an end of charge lamp......very basic electronics.... if you want to charge faster ( as per some festo, metabo, bosch.....) like 15 minutes you do need some elctronic smarts.

For over 20 years end of charge by temperature sense has been the norm for fast charge nicad.and is perfectly satisfactory and a reasonable method of sensing the charge of Nicad.....delta sensing will only be in the more expensive products STILL.... and has only come into vogue since lithium has been on the market because you can not sense charge on lithium reliably by temperature or if you tried it would be too late

As for low end tools charged by a plug pack.... mostly they wont be fast charge and most people here would not be buying that far down the food chain.

Any preasure relief in dry cell batteries is not designed like lead acid as a part of normal operation, its primary concept is to minimise the risk of explosion. Talking about venting cells as it is a normal part of operation in nicad is a false concept.....If the battery isnt terminaly damged by the causes of venting the rapid corrosion from the vented products will ensure a rapid demise particularly cells in enclosed packs.

Sounds like you are quoting from the makita sales brocure.... or did you paste that from their web site.
The reason a lithium charger has to have all that stuff is that if it didn't.... it would turn into a lump of melting, burning, toxic waste...... another thing that adds to the cost of lithium.

As a technician with over 30 years experience in field and workshop service and having pulled my fair share of failed batteries and battery packs and battery powered equipment apart ( including powertools, communications and broadcast equipment, professional audio, with batteries of all types and sizes) and having distributed batteries for a living at one time I think I know What I am talking about and how this realy works in the world.:

cheers

Originally Posted by soundman

The methods of charging nicad/ NimH are so very different to that of lithium that I find it unlikly that a manufacturer would build a product compatable with both.......although someone like festo might be crazy enough to try.

And the have. The new Festool T-series drills (T12 and T15) come with a charger that will charge Li-ion, NiMh, and NiCd. This is because this new drill is itself is designed to run the Li-ion batteries (that come with it), or an owners batteries from earlier model Festool drills they might already own (specifically the TDK and C12 models).

yep festo the masters of the expensive and unlikley....

Correct me if I am wrong but this is the same company which makes a 14" ( or something like it) hand held circular saw.

So hands up anybody who has seen more than 1 festo battery drill on a construction site.

cheers

Originally Posted by soundman

yep festo the masters of the expensive and unlikley....

Correct me if I am wrong but this is the same company which makes a 14" ( or something like it) hand held circular saw.

So hands up anybody who has seen more than 1 festo battery drill on a construction site.

cheers

Oh come on soundman. Just because a company actually bothers to make tools not singularly catering to the mass market, but actually looking at jobs people do and ensuring a solution to the problems, you imply they are unsound or something.

Festool do indeed make a circular saw with 160mm depth of cut. What a beast. But in Europe it has a particular set of applications which we see little of here, so it might look strange, Mostly large beam and rafter construction. Here these same saws are mostly used to cut refrigeration panels. And those who finally employ these saws to do just that find the improved efficiency and finish vastly superior to anything else they have used before on site.

As to Festool drills on site, you might not find them in multiples on the average building site because guys are afraid they will get knocked off or abused. But I know a a number of guys (who mostly work for themselves and buy their own tools) that have multiple Festool drills on site in their own kit. This actually amazes me as the Festool Centrotec system is designed to avoid the need to have multiple drills, but some prefer the best of both worlds.

I agree with you about 24v batteries on cordless tools. Just to note: Festool new drill the T-12 is actually (for Li-ion) 10.8V. And the T15 is (for Li-ion) 14.4V. And for their industrial drills (branded Protool), they use max 18v. Festool prefer to employ more efficient motor technology (also brushless) rather than huge batteries to provude the user with grunt.

Originally Posted by soundman

Oh BTW.... lets not worry too much about what is available in US dollars because most people here will be buying a 240volt supplied charger and paying Australian dollars.

No let's worry about the US market. Feel free to continue paying twice as much or more for the same gear if you like but for the price and minor inconvenience of a transformer I'm happy not to.

The dewalt lithium charger charges lithium and nicad batteries without the need for any adaptors. Works straight out of the box and is compatible with all from 7.2-18v nicd and lithium batteries.