Recently got a catalogue from ITS London. On the page listing power tool
batteries is the following, verbatim;
-----------------------------------------------
Are you confused about the various battery types available?
This information is a guide only, only batteries suited to your charger and
specific tool should be used.

NiCD (Nickel Cadmium). Entry level rechargeable battery which must be fully
discharged before recharging. Failure to do so can reduce battery life.

NiMH (Nickel Metal Hydride). These batteries have no memory effect
therefore can be 'topped up' or charged at any time without affecting
battery life. NiMH batteries also tend to out perform NiCD batteries in
high drain applications.

Li-ion (Lithium -ion). The newest battery technology for cordless power
tools, with no memory effect they can be 'topped up' with no effect to
battery life. The main benefit to this battery type is the weight - up to
40% lighter that NiMH batteries makes these the favourite for power tools.

-------------------------------------------------

To a battery layman like me, this is a golden nugget of information. Makes
it perfectly clear which is which.

So, first of all, is it by & large all true?

If so, should we steal it for the Wiki?



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On Wed, 01 Jul 2009 21:12:16 GMT, "The Medway Handyman"
wrote:

(I've re-ordered this to make the reply easier to follow)

To a battery layman like me, this is a golden nugget of information. Makes
it perfectly clear which is which.

So, first of all, is it by & large all true?

Not really. To call NiMH "entry level" is sales crap to get idiots to
buy more expensive batteries. One advantage NiCd has over other
technologies is it is rugged and works better at extremes of
temperature.

NiCD (Nickel Cadmium). Entry level rechargeable battery which must be fully
discharged before recharging. Failure to do so can reduce battery life.

NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

NiMH (Nickel Metal Hydride). These batteries have no memory effect

Neither do NiCd.

therefore can be 'topped up' or charged at any time without affecting
battery life.

So can NiCd with the right charger.

NiMH batteries also tend to out perform NiCD batteries in high drain applications.

Wrong. NiCd can have better high drain characteristics than NiMH. It
is a function of battery design not chemistry.

Li-ion (Lithium -ion). The newest battery technology for cordless power
tools, with no memory effect

Just like NiMH and NiCd.

they can be 'topped up' with no effect to battery life.

Not true, Lithium batteries have a finite charge cycle life and each
charge, whether partial or full eats into it.

The main benefit to this battery type is the weight - up to
40% lighter that NiMH batteries makes these the favourite for power tools.

They are not necessarily lighter, they certainly have a better energy
capacity per unit of weight so you can have the same weight and more
energy or the same energy and less weight.

If so, should we steal it for the Wiki?

I'd rather something a bit more balanced.

"Peter Parry" wrote in message
news
On Wed, 01 Jul 2009 21:12:16 GMT, "The Medway Handyman"
wrote:

(I've re-ordered this to make the reply easier to follow)

To a battery layman like me, this is a golden nugget of information.
Makes
it perfectly clear which is which.

So, first of all, is it by & large all true?

Not really. To call NiMH "entry level" is sales crap to get idiots to
buy more expensive batteries. One advantage NiCd has over other
technologies is it is rugged and works better at extremes of
temperature.

NiCD (Nickel Cadmium). Entry level rechargeable battery which must be
fully
discharged before recharging. Failure to do so can reduce battery life.

NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

NiMH (Nickel Metal Hydride). These batteries have no memory effect

Neither do NiCd.

therefore can be 'topped up' or charged at any time without affecting
battery life.

So can NiCd with the right charger.

NiMH batteries also tend to out perform NiCD batteries in high drain
applications.

Wrong. NiCd can have better high drain characteristics than NiMH. It
is a function of battery design not chemistry.

Li-ion (Lithium -ion). The newest battery technology for cordless power
tools, with no memory effect

Just like NiMH and NiCd.

they can be 'topped up' with no effect to battery life.

Not true, Lithium batteries have a finite charge cycle life and each
charge, whether partial or full eats into it.

The main benefit to this battery type is the weight - up to
40% lighter that NiMH batteries makes these the favourite for power tools.

They are not necessarily lighter, they certainly have a better energy
capacity per unit of weight so you can have the same weight and more
energy or the same energy and less weight.

If so, should we steal it for the Wiki?

I'd rather something a bit more balanced.

NiCd seem pretty rare now presumably because of recycling and Cd toxicity.

I'd have said NiMH are now the standard, Li ion started in phones etc and
are moving to tools, but at a price.

For individual AA cells in cameras and GPS, I get much better performance
from NiMH than NiCd, but some of that is almost certainly thanks to using a
better charger which does each cell individually. I agree with Peter that
chargers have got better anyway and that tends to help NiMH.

I don't know whether the often described NiCd "memory effect" is true or
not, but over time I've seemed to end up with more "bad cells" in sets of
NiCd than NiMH.

In article , "newshound" wrote:


NiCd seem pretty rare now presumably because of recycling and Cd toxicity.

I'd have said NiMH are now the standard, Li ion started in phones etc and
are moving to tools, but at a price.

For individual AA cells in cameras and GPS, I get much better performance
from NiMH than NiCd, but some of that is almost certainly thanks to using a
better charger which does each cell individually. I agree with Peter that
chargers have got better anyway and that tends to help NiMH.

I don't know whether the often described NiCd "memory effect" is true or
not, but over time I've seemed to end up with more "bad cells" in sets of
NiCd than NiMH.

The memory effect occurs when NiCd is charged after a fixed discharge
rate for a fixed time, as when charged by solar cells. When the time or
load is random, as with power tools, it's not a problem.

"Standard" NiMH have a relatively high self-discharge rate, greater than
NiCd. This means they lose their charge, at a rate of the order of
10%/month, when not used. There are now NiMH types (e.g. Sanyo Eneloop)
that address this problem, with some 80%-90% charge remaining after a
year on the shelf.

Li-ion doesn't have a similar high self-discharge rate, so is useful in
tools that are infrequently used.

--
John W
I you really want to mail me, replace the obvious with co.uk twice

Peter Parry wrote:
On Wed, 01 Jul 2009 21:12:16 GMT, "The Medway Handyman"
wrote:

(I've re-ordered this to make the reply easier to follow)

To a battery layman like me, this is a golden nugget of information.
Makes
it perfectly clear which is which.

So, first of all, is it by & large all true?

Not really. To call NiMH "entry level" is sales crap to get idiots to
buy more expensive batteries. One advantage NiCd has over other
technologies is it is rugged and works better at extremes of
temperature.

I'd assumed that ('entry level') to be true, because all of the 'super
deals' on DeWalt & Makita include low capacity (1.3a/hr) NiCD batteries,
presumably because they are cheaper?

ISTR that Makita with red NiCD batteries were at one time called Maktek and
offered as a lower cost alternative to a Makita with black NiMH batteries.

NiCD (Nickel Cadmium). Entry level rechargeable battery which must
be fully discharged before recharging. Failure to do so can reduce
battery life.

NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

NiMH (Nickel Metal Hydride). These batteries have no memory effect

Neither do NiCd.

Is that so? I've always believed NiCD did have a memory effect.

therefore can be 'topped up' or charged at any time without affecting
battery life.

So can NiCd with the right charger.

Is this the crux of the matter? Is the charger in some respects as/more
important than the batteries?

NiMH batteries also tend to out perform NiCD batteries in high drain
applications.

Wrong. NiCd can have better high drain characteristics than NiMH. It
is a function of battery design not chemistry.

Li-ion (Lithium -ion). The newest battery technology for cordless
power
tools, with no memory effect

Just like NiMH and NiCd.

they can be 'topped up' with no effect to battery life.

Not true, Lithium batteries have a finite charge cycle life and each
charge, whether partial or full eats into it.

The main benefit to this battery type is the weight - up to
40% lighter that NiMH batteries makes these the favourite for power
tools.

They are not necessarily lighter, they certainly have a better energy
capacity per unit of weight so you can have the same weight and more
energy or the same energy and less weight.

If so, should we steal it for the Wiki?

I'd rather something a bit more balanced.

This is what I'm after Peter, the choice of batteries is very confusing for
the average DIY guy, me included. I recently bought a new 14.4v NiMH 3.6
a/hr battery for my Makita DD because it seemed like a good deal. Truth be
told I didn't really know if NiMH was a better or worse deal than NiCD.

So, to rephrase my question, could we have a section on batteries (power
tool) in the Wiki to make matters clear for the battery numpty like me?


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

Quality of cells is very important.
Generic NiCad NiMH power tool batteries tend to be noticeably inferior
to genuine Makita/Bosch.
Generic or off-brand L-Ion laptop batteries can offer as little as 9
month lifespan compared to years on others.

I am dubious about L-Ion on power tools for the moment - there tends
to be just 1 battery, charge cycle limit is finite, they cost a
fortune, generics or off-brand might be significantly worse than
branded for only a limited difference in eye-watering price.

Yes, if it means finishing a job a generic battery can be perfect.
However even Pro cordless tools pale against even quite modest mains
tools.

L-Ion is perhaps useful with 24V SDS monsters - where any weight
saving makes them less unwieldy.

I'd go for a 3-battery special-offer vs 1-battery or more expensive 2-
battery L-Ion.

On Jul 1, 10:12*pm, "The Medway Handyman"
wrote:
Recently got a catalogue from ITS London. *On the page listing power tool
batteries is the following, verbatim;
-----------------------------------------------
Are you confused about the various battery types available?
This information is a guide only, only batteries suited to your charger and
specific tool should be used.

NiCD (Nickel Cadmium). *Entry level rechargeable battery which must be fully
discharged before recharging. *Failure to do so can reduce battery life..

NiMH (Nickel Metal Hydride). *These batteries have no memory effect
therefore can be 'topped up' or charged at any time without affecting
battery life. *NiMH batteries also tend to out perform NiCD batteries in
high drain applications.

Li-ion (Lithium -ion). *The newest battery technology for cordless power
tools, with no memory effect they can be 'topped up' with no effect to
battery life. *The main benefit to this battery type is the weight - up to
40% lighter that NiMH batteries makes these the favourite for power tools..

-------------------------------------------------

To a battery layman like me, this is a golden nugget of information. *Makes
it perfectly clear which is which.

So, first of all, is it by & large all true?

If so, should we steal it for the Wiki?

--
Dave - The Medway Handymanwww.medwayhandyman.co.uk

The observation on NiMH with regard to high-drain applications seems
rather strange -- I'd reckoned that was one of the few things to be
said for NiCd batteries.

However as things stand at the moment I reckon that the Li-ion
technology is in practice the best all-rounder available. In my
experience good Li-ion batteries can take a pounding for years. I use
a lot of them -- quite a number of mobile phones, satnavs etc.-- and
it's only one I've ever had to replace and that was after years of
service and a mixture of charging regimes.

My Makita cordless drill is Li-ion. For me, the most relevant factor
in that choice had to be that, since it wasn't going to be in use
every day and might lie a month between uses, it wouldn't completely
self-discharge if left lying, For someone using a power tool every
day, that wouldn't be a relevant factor. In any case, it's Li-ion
that seems to be the choice for top-of-range tools increasingly and
that's where the development money is being spent.

My experience with Li-ion has been good all round. As, for that
matter, has been my experience with ITS London (though that particular
Makita didn't come from them). Nice guys who generally know their
stuff better than most such operations when you talk to them.

In article ,
The Medway Handyman wrote:
Recently got a catalogue from ITS London. On the page listing power
tool batteries is the following, verbatim;
----------------------------------------------- Are you confused about
the various battery types available? This information is a guide only,
only batteries suited to your charger and specific tool should be used.

NiCD (Nickel Cadmium). Entry level rechargeable battery which must be
fully discharged before recharging. Failure to do so can reduce
battery life.

That is total ********. *Totally* discharging a Ni-Cad battery - ie one
with more than one cell - is not a good idea. It should simply be charged
when the performance drops off.

NiMH (Nickel Metal Hydride). These batteries have no memory effect
therefore can be 'topped up' or charged at any time without affecting
battery life. NiMH batteries also tend to out perform NiCD batteries in
high drain applications.

Memory effect is an urban myth.

Li-ion (Lithium -ion). The newest battery technology for cordless power
tools, with no memory effect they can be 'topped up' with no effect to
battery life. The main benefit to this battery type is the weight - up
to 40% lighter that NiMH batteries makes these the favourite for power
tools.

-------------------------------------------------

To a battery layman like me, this is a golden nugget of information.
Makes it perfectly clear which is which.

So, first of all, is it by & large all true?

If so, should we steal it for the Wiki?

No.

--
*There's no place like www.home.com *

Dave Plowman London SW
To e-mail, change noise into sound.

On 1 July, 22:12, "The Medway Handyman"
wrote:

So, first of all, is it by & large all true?

It's close enough that you won't be misled into bad decisions as a
result.

One thing worth adding is Cd toxicity, and the imminent phase-out of
NiCd.

On Wed, 01 Jul 2009 23:26:11 GMT, "The Medway Handyman"
wrote:

Peter Parry wrote:

NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

NiMH (Nickel Metal Hydride). These batteries have no memory effect

Neither do NiCd.

Is that so? I've always believed NiCD did have a memory effect.

No, its one of the oldest red herrings going. It is possible to
produce a loss of capacity in both NiCd and NiMH by consistently
overcharging them but it has nothing to do with how far you discharge
them.

therefore can be 'topped up' or charged at any time without affecting
battery life.

So can NiCd with the right charger.

Is this the crux of the matter? Is the charger in some respects as/more
important than the batteries?

Absolutely. Broadly NiCd/NiMH chargers fall into one of three groups.
Firstly you have the ones which take a long time - at least 10 hours,
to charge a battery. These treat the battery well and won't harm a
battery if its only slightly discharged when you put it on them or if
you leave it a few hours too long. Charging at 10th of capacity
(C/10) is the safest way of charging but not terribly practical for
tools in use all day.

Secondly you have the ones supplied with cheap battery tools. These
usually charge in somewhere between 3 and 5 hours and have no charge
regulation worth talking about. These are damaging to batteries and
if left for more than a short time after charge is complete (as short
as an hour) will often significantly damage them. The poor battery
life on cheap tools is often a function of the poor chargers rather
than the batteries.

Finally you have the well controlled 1hr fast chargers which monitor
the battery state and modify the charging accordingly. Really good
charge control is essential for LiOn as overcharging turns them into
small explosive devices.

Basically if a battery is getting hot on charge it is being hurt.

So, to rephrase my question, could we have a section on batteries (power
tool) in the Wiki to make matters clear for the battery numpty like me?

We could certainly produce a chart comparing the characteristics of
the various battery types. There isn't a single "best" one for all
purposes. If we did no more than warn against the damage the cheap
5hr chargers do to batteries it would be useful.

John MacLeod wrote:


My experience with Li-ion has been good all round. As, for that
matter, has been my experience with ITS London (though that particular
Makita didn't come from them). Nice guys who generally know their
stuff better than most such operations when you talk to them.

I've dealt with ITS a few times & found it a positive experience. They do
some very good deals as well.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

Peter Parry wrote:
On Wed, 01 Jul 2009 23:26:11 GMT, "The Medway Handyman"
wrote:

Peter Parry wrote:

NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental
characteristics which make a difference. NiMH have a slightly
higher charge capacity than NiCd for a given weight.

NiMH (Nickel Metal Hydride). These batteries have no memory effect

Neither do NiCd.

Is that so? I've always believed NiCD did have a memory effect.

No, its one of the oldest red herrings going. It is possible to
produce a loss of capacity in both NiCd and NiMH by consistently
overcharging them but it has nothing to do with how far you discharge
them.

therefore can be 'topped up' or charged at any time without
affecting battery life.

So can NiCd with the right charger.

Is this the crux of the matter? Is the charger in some respects
as/more important than the batteries?

Absolutely. Broadly NiCd/NiMH chargers fall into one of three groups.
Firstly you have the ones which take a long time - at least 10 hours,
to charge a battery. These treat the battery well and won't harm a
battery if its only slightly discharged when you put it on them or if
you leave it a few hours too long. Charging at 10th of capacity
(C/10) is the safest way of charging but not terribly practical for
tools in use all day.

Secondly you have the ones supplied with cheap battery tools. These
usually charge in somewhere between 3 and 5 hours and have no charge
regulation worth talking about. These are damaging to batteries and
if left for more than a short time after charge is complete (as short
as an hour) will often significantly damage them. The poor battery
life on cheap tools is often a function of the poor chargers rather
than the batteries.

Finally you have the well controlled 1hr fast chargers which monitor
the battery state and modify the charging accordingly. Really good
charge control is essential for LiOn as overcharging turns them into
small explosive devices.

Basically if a battery is getting hot on charge it is being hurt.

So, to rephrase my question, could we have a section on batteries
(power tool) in the Wiki to make matters clear for the battery
numpty like me?

We could certainly produce a chart comparing the characteristics of
the various battery types. There isn't a single "best" one for all
purposes. If we did no more than warn against the damage the cheap
5hr chargers do to batteries it would be useful.

Thanks Peter, very helpful.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

"Peter Parry" wrote in message
news
NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

Is that really true? Are NiCds a lot less dense then? Eg AAs - what's the
capacity of a good NiMH vs NiCd these days? (2500 vs 700 mAH?)

"Dave Plowman (News)" wrote in message
...
In article ,
The Medway Handyman wrote:
Recently got a catalogue from ITS London. On the page listing power
tool batteries is the following, verbatim;
----------------------------------------------- Are you confused about
the various battery types available? This information is a guide only,
only batteries suited to your charger and specific tool should be used.

NiCD (Nickel Cadmium). Entry level rechargeable battery which must be
fully discharged before recharging. Failure to do so can reduce
battery life.

That is total ********. *Totally* discharging a Ni-Cad battery - ie one
with more than one cell - is not a good idea. It should simply be charged
when the performance drops off.


Totally discharging a Ni-Cd battery is one of the two ways to kill it (the
other is of course poor charging) and the "battery conditioners" which were
popular at one time which did this were one of the worst things you could do
to them. The reason is that internally a battery consists of more than one
cell in series and these will initially have very slightly different
capacities. As the battery approaches total depletion the weakest cell will
become reverse biased by its friends and this is *very* bad news, weakening
it still further. Repeat this total discharge a few times and the weakest
cell will eventually fail.

From a longevity POV the best thing you can do is to charge the battery when
it's performace starts to drop off *using a high quality charger*. And
thereby lies the rub, if you recharge at this point using a poor charger it
will overcharge the battery and cause damage through that mechanisum
instead.

NiMH (Nickel Metal Hydride). These batteries have no memory effect
therefore can be 'topped up' or charged at any time without affecting
battery life. NiMH batteries also tend to out perform NiCD batteries in
high drain applications.

Memory effect is an urban myth.


There's an interesting back story to this which I've researched a bit and
believe to be true. NiCad's do suffer from memory effect but, as others
have said, only if repeatedly charged and discharged at the same rate for
the same time. There are good chemical reasons for this which I won't go
into here.

Now this effect is of course unobservable in normal daily life because they
are never used that way but when NASA started using them in space that's
exactly how they were treated. The charge/discharge cycle is dictated by
the orientation and trajectory of the spacecraft (ie. how its solar panels
align with the sun) and tends to be highly routine and the drain tends to
follow set patterns. NASA had to go away and discover how and why their
batteries were failing, which they did, and when they made this known the
manufacturers and the public saw it as the reason NiCad's died, missing the
detail and blaming memory effect rather than the crap chargers for killing
batteries.

On Thu, 2 Jul 2009 13:09:02 +0100, "Clive George"
wrote:

"Peter Parry" wrote in message
news
NiMH and NiCd have very similar charging and discharge
characteristics. NiMH batteries often come with better quality
chargers and it is this rather than their fundamental characteristics
which make a difference. NiMH have a slightly higher charge capacity
than NiCd for a given weight.

Is that really true? Are NiCds a lot less dense then? Eg AAs - what's the
capacity of a good NiMH vs NiCd these days? (2500 vs 700 mAH?)

Both have similar characteristics as far as their chemistry is
concerned. Because NiCd are due to be phased out there has not been
much development of them for a few years. As a result new
manufacturing processes are being seen in NiMH giving better
capacities for the same battery size. That said "capacity" figures
need to be treated with caution if you don't know the discharge regime
they were tested under. I've had NiCd 1AH batteries which had better
capacity than 2AH NiMH in one particular application.