NiMh charging formula

Thanks for all the responses.

Andy

On Sun, 26 Oct 2014 12:50:05 -0400, rickman <gnuarm@gmail.com> wrote:

>On 10/26/2014 9:11 AM, Jan Panteltje wrote:
>> Regarding the impossibility of charging eneloops in a safe way i have decided not to buy these
>> anymore.
>
>Lol, have you considered using the charger built to charge them?

The official Sanyo NC-MQN06 charger is a rather slow charger.  Looking
at the docs, it estimates 7 hrs charge for 2 AA cells.  Working
backwards from the stated capacity of 2000 ma-hr, that would be:
   2000 ma-hr / 7.0 hr = 286 ma
or about 0.15C, which is rather slow.  The quality of this charger is
debatable:
<http://www.candlepowerforums.com/vb/showthread.php?218747-An-informal-look-at-the-Sanyo-NC-MQN06U-%96-charging-in-pairs>

I haven't tried using the current models:
<http://www.panasonic-eneloop.eu/eneloop-products/chargers.html>
Note the differences in charge control:
   BQ-CC16    Smart Charge 1/-delta-V /Timer
   BQ-CC17    delta-T  /Timer
   BQ-CC18    Timer cut
Notice the timer to prevent killing the battery by leaving it in the
charger forever.  Yes, you can kill a NiMH by continuous trickle
charging.  If you must buy one of these, I suggest the BQ-CC16 as the
other are probably battery killers.

The recommended current for the older BK3-LCC AA cells is 1000 ma for
1.1 hrs.   Recommended charge current for the newer AA cells is 2000
ma for 1.1 hrs.  They are currently on the 4th generation cells.  
<http://en.wikipedia.org/wiki/Eneloop>
See the various data sheets:
<http://www.panasonic-eneloop.eu/home/technology/data-sheets.html>
What this means is that all Eneloop cells are not the same and that
the various model chargers are not interchangeable.

I've had very good luck using Eneloop AA batteries in my various
cameras (Canon S5-IS, Canon A40, etc).  I've been using my cell phone
and tablets as cameras more often and have put the digital cameras
aside.  I need to use them recently.  6 months of sitting on the shelf
and they were about 80% of full charge.  If I had done that with a
conventional NiMH battery, they would all have been totally
discharged.  Highly recommended, but be careful what you use for a
charger.

>Duh, that is the point of the Enloops.  I believe Enloops are some 50 to 
>100 times slower to self discharge.

<http://www.candlepowerforums.com/vb/showthread.php?149804-Eneloop-Self-Discharge-study>
It's much more.  The Eneloop cells drop to about 85% in about 1 month,
80% at 2 months, and stay at that level forever.  See the 2nd graph.
The Panasonic press releases claim 70% of charge after 5 years of
storage:
<http://www.panasonic-eneloop.eu/fileadmin/web_data/Press_Area/Press_Releases_and_News_ENG/Press_Release_eneloop_1800_12092012_EN.pdf>

>> Panasonic bought eneloop recently... so whatinaname.
>
>Uh, are they dropping the Enloop name, I doubt it.  Does Panasonic have 
>a line of slow self discharge NiMH?  I expect not.

It's still being sold as Eneloop.  
<http://www.panasonic-eneloop.eu>
Dunno about other LSD (low self discharge) calls from Panasonic.
-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

On 26/10/14 17.31, Jeff Liebermann wrote:
> On Sun, 26 Oct 2014 11:08:32 +0100, Robert Roland<fake@ddress.no>
> wrote:
>
>> On Sat, 25 Oct 2014 20:45:38 -0700, Jeff Liebermann<jeffl@cruzio.com>
>> wrote:
>>
>>> One accidental overcharge and your
>>> battery is dead.
>>
>> Not true.
>
> I beg to differ.
>
>> Early NiMH batteries were quite intolerant of overcharging, but modern
>> batteries are much more robust. Not quite as robust as NiCd, though.
>>
>> In fact, some amount of overcharge is necessary in order to keep the
>> cells in a battery balanced.
>
> Let's see if I understand what you're saying.  In a series string of
> NiMH cells, one must overcharge the good cells in order to bring the
> not-so-good cells up to the good cell voltage?  Is that what you're
> saying?  If so, this sounds like a variation on "battery conditioning"
> which works well at killing batteries.
...

Hi Robert, Jeff and others

The worst thing for any rechargable (except NiFe) are reverse-charging 
of e.g. one cell. That happens because cells have different:
(1) self-discharge characteristics
(2) capacity
(3) maybe different internal impedance as a function of charge-level.

Reverse-charging even one cell will shorten its live hugely. And when 
one cells is dead the whole battery fails alot faster than maybe 200 
full cycles? - and not the advertised 1000-2000 full (100%) cycles.

The best you can do for your serially connected cells are to survey your 
cells when discharging.

But this will typically cost a microcontroller and some wires to each 
cell end, and a power switch that is controlled by microcontroller in 
question.

The system is called a Battery management system (BMS):
https://en.wikipedia.org/wiki/Battery_management_system

If a cell is overcharged, but is will shorten the cell life some, 
especially if the cell vent - which means that it looses water (=higher 
internal impedance).

-

Li-ion (excluding LiFePO4!) cell must not be overcharged or else it also 
get a lot shortened life - or even destabilize.

If a Li-ion (excluding LiFePO4!) cell is over-discharging (<2,5V but >0V 
and not even reverse-charged), it will destabilize. And when later 
charged it will be prone to burning and explosion.

It a Li-ion (excluding LiFePO4!) get to high a charging current or 
discharging current, it will destabilize.

That is why (nearly) all Li-ion (e.g. computer) Li-ion batteries have a BMS.

-

LiFePO4 can handle overcharging, but this will shorten the cell life 
some, especially if the cell vent - like any other chemistry - which 
means that it looses water (=higher internal impedance).

-

It is possible to buy battery BMS-controllers e.g.:
* TI: bq20z60-R1, bq29330, bq294xy...
* Atmel: ATA6870N *n +(ATmega32HVE2 or ATmega64HVE2)

Atmel ATA6870N Li-Ion, NiMH Battery Measuring, Charge Balancing and 
Power-supply Circuit datasheet:
http://www.atmel.com/Images/Atmel-9317-Li-Ion-Battery-Management-ATA6870N_Datasheet.pdf

Look at the sources here:
https://da.wikipedia.org/wiki/Batteristyresystem#Kilder.2Freferencer

-

There is even an interface standard (Smart Battery System, SBS):
https://en.wikipedia.org/wiki/Smart_Battery_System

A battery with a BMS is called a smart battery:
https://en.wikipedia.org/wiki/Smart_Battery

A charger that can "talk" with a battery with a BMS, is called a smart 
battery charger:
https://en.wikipedia.org/wiki/Smart_battery_charger

Glenn

On 26/10/14 17.31, Jeff Liebermann wrote:
 > On Sun, 26 Oct 2014 11:08:32 +0100, Robert Roland<fake@ddress.no>
 > wrote:
 >
 >> On Sat, 25 Oct 2014 20:45:38 -0700, Jeff Liebermann<jeffl@cruzio.com>
 >> wrote:
 >>
 >>> One accidental overcharge and your
 >>> battery is dead.
 >>
 >> Not true.
 >
 > I beg to differ.
 >
 >> Early NiMH batteries were quite intolerant of overcharging, but modern
 >> batteries are much more robust. Not quite as robust as NiCd, though.
 >>
 >> In fact, some amount of overcharge is necessary in order to keep the
 >> cells in a battery balanced.
 >
 > Let's see if I understand what you're saying.  In a series string of
 > NiMH cells, one must overcharge the good cells in order to bring the
 > not-so-good cells up to the good cell voltage?  Is that what you're
 > saying?  If so, this sounds like a variation on "battery conditioning"
 > which works well at killing batteries.
...

Hi Robert, Jeff and others

The worst thing for any rechargable (except NiFe) is reverse-charging of 
e.g. one cell. That happens because cells have different:
(1) self-discharge characteristics
(2) capacity
(3) maybe different internal impedance as a function of charge-level.

Reverse-charging even one cell will shorten its life hugely. And when 
one cells is dead, the whole battery fails a lot faster than maybe 200 
full cycles? - and not the advertised 1000-2000 full (100%) cycles.

The best you can do for your serially connected cells are to monitoring 
your cells when discharging.

But this will typically cost a microcontroller and some wires to each 
cell end, and a power switch that is controlled by microcontroller in 
question.

The system is called a Battery management system (BMS):
https://en.wikipedia.org/wiki/Battery_management_system

If a cell is overcharged, it will shorten the cell life some, especially 
if the cell vent - which means that it looses water (=higher internal 
impedance).

-

Li-ion (excluding LiFePO4!) cell must not be overcharged or else it also 
get a lot shortened life - or will even destabilize.

If a Li-ion (excluding LiFePO4!) cell is over-discharging (<2,5V but >0V 
and not even reverse-charged), it will destabilize. And when later 
charged it will be prone to burning and explosion.

It a Li-ion (excluding LiFePO4!) get to high a charging current or 
discharging current, it will destabilize.

That is why (nearly) all Li-ion (e.g. computer) Li-ion batteries have a BMS.

-

LiFePO4 can handle overcharging, but this will shorten the cell life 
some, especially if the cell vent - like any other chemistry - which 
means that it looses water (=higher internal impedance).

-

It is possible to buy battery BMS-controllers e.g.:
* TI: bq20z60-R1, bq29330, bq294xy...
* Atmel: ATA6870N *n +(ATmega32HVE2 or ATmega64HVE2)

Atmel ATA6870N Li-Ion, NiMH Battery Measuring, Charge Balancing and 
Power-supply Circuit datasheet:
http://www.atmel.com/Images/Atmel-9317-Li-Ion-Battery-Management-ATA6870N_Datasheet.pdf

Look at the sources here:
https://da.wikipedia.org/wiki/Batteristyresystem#Kilder.2Freferencer

-

There is even an interface standard (Smart Battery System, SBS):
https://en.wikipedia.org/wiki/Smart_Battery_System

A battery with a BMS is called a smart battery:
https://en.wikipedia.org/wiki/Smart_Battery

A charger that can "talk" with a battery with a BMS, is called a smart 
battery charger:
https://en.wikipedia.org/wiki/Smart_battery_charger

Glenn

On 10/25/2014 7:36 PM, Andy K wrote:
> I have a "dumb" NiMh/NiCd charger.
>
> For 9 volt batteries, it specifies 25 milliamps.
>
> The charger manual gives this charge formula.
>
> Charging time(h) = 1.2 x battery capacity (mAh)
>                     --------------------
>                           charging current (mA)
> 13.44 hrs.
>
>
> Is is formula useful or is there something better that factors in the starting Voltage ?
>
> Thanks.
>
>

The formula is useful, as far as it goes. Factoring in the
starting voltage can be done simply by adding a shut off or
taper circuit. (Of course best would be a good smart charger.)

The add on circuit is adjusted to detect the fully charged
voltage (aka "terminal voltage"), then taper the charge to
something like C/50, or shut the charge off completely.  The
initial state of charge affects how long the "dumb charge"
circuit will take to reach terminal voltage. Once terminal
voltage is reached, the add on circuit prevents excessive
charging.

A TL431, a trimpot and 2 resistors is all you need for an
add on circuit to taper the charge - the shut off circuit
would need a few more components.

Ed

On 10/26/2014 11:31 AM, Jeff Liebermann wrote:
> On Sun, 26 Oct 2014 11:08:32 +0100, Robert Roland <fake@ddress.no>
> wrote:
>
>> On Sat, 25 Oct 2014 20:45:38 -0700, Jeff Liebermann <jeffl@cruzio.com>
>> wrote:
>>
>>> One accidental overcharge and your
>>> battery is dead.
>>
>> Not true.
>
> I beg to differ.
>
>> Early NiMH batteries were quite intolerant of overcharging, but modern
>> batteries are much more robust. Not quite as robust as NiCd, though.
>>
>> In fact, some amount of overcharge is necessary in order to keep the
>> cells in a battery balanced.
>
> Let's see if I understand what you're saying.  In a series string of
> NiMH cells, one must overcharge the good cells in order to bring the
> not-so-good cells up to the good cell voltage?  Is that what you're
> saying?  If so, this sounds like a variation on "battery conditioning"
> which works well at killing batteries.
>
>
> LiIon battery chargers have the same problem with series connected
> cells.  The difference is that while NiMH cells might survive some
> overcharge, LiIon cells short and die rather easily.  To solve the
> problem of maintaining identical and balanced cell voltages, the RC
> (radio control) industry uses a "balance charger":
> <https://www.google.com/search?q=balance+charger&tbm=isch>
> These have two connectors to the battery.  One pair of terminals for
> the high current charge/discharge current, and another connector that
> goes directly across each cell to monitor and control the charge
> current for each cell individually.  Something like this might also
> work with NiMH, but I haven't found any balance chargers that will do
> it.  I suspect that's because LiIon and mutations are the future,
> while the use of NiMH is decreasing rapidly.
>
> One of my experiments was to see how quickly I could fast charge NiCd
> and NiMH cells.  Since these chemistries only get hot when
> overcharged, I suspected that I could safely charge them at ridiculous
> rates, as long as I didn't overcharge.  Trying to detect the 5mv drop
> in terminal voltage at EOC was futile as warm contacts would ruin that
> measurement.  Most cells were 2000 ma-hr AA NiMH cells that managed to
> deliver about 1200 ma-hr at 1C discharge loads[1].
> <http://802.11junk.com/jeffl/NiMH/Duracelll-NiMH-2050.jpg>
> I would then quick charge them at up to about 5C (10 Amps) for about
> 12-15 minutes.  Knowing the initial SoC (state of charge) and cell
> capacity was critical.
>
> Of course, I intentionally overcharged some cells, just to see what
> happened.  I determined that things change at about 75% of capacity.
> Below 75%, the charging efficiency is 100%.  If I charged at any rate
> to 75% of full capacity, I could discharge the cell (at C/10) and get
> all of it back.  Above 75%, everything would change.  If I counted
> coulombs and charged to 100%, the charging efficiency dropped from
> 100% to about 85% with the loss going up in heat.  The heat was a
> waste of charging energy.  It also caused the cell to deteriorate in
> both capacity and self discharge rate.
>
> Notice that the cell does not magically stay cold at 99% of charge,
> and explode at 101% of charge.  It's an exponential curve, that starts
> at about 75% and climbs rapidly.  The 100% point seems to have been
> selected to produce a reasonable number of charge cycles, safe
> charging temperature, and approximate correlation with the -5mv NDV
> (negative delta voltage) EoC point.  If you want your NiMH batteries
> to live forever, just set the EoC to about 75% and don't go anywhere
> near 100% charge.  I attempted to reproduce the NiMH graph at:
> <http://batteryuniversity.com/learn/article/battery_performance_as_a_function_of_cycling>
> <http://batteryuniversity.com/_img/content/cycle3.jpg>
> which shows loss of cell capacity after 300 charge cycles.  At 100%
> charge (1C charge, 1C discharge, 4 hr cycle for about 100 days), using
> a commercial smart charger, my results were fairly similar to the
> graph.  However, at 75% of charge, there was little decrease in
> capacity up to 700 charge cycles, when I gave up.  Unfortunately, I
> discovered too late that my battery holder had a problem and that the
> contact resistance had ruined my internal resistance measurements.
>
> Anyways, I think you can see what might happen as you approach 100%
> charge with an NiMH battery.  I don't think going over 100% is a very
> good idea.
>
> "Charging Nickel-metal-hydride"
> <http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride>
>
>
>
> [1]  NiMH cells are rated for capacity at C/5 discharge rate to 1.0v.
> For a 2000 ma-hr cell, it takes about 10 hrs to run the discharge
> test.  Typical data sheet:
> <http://data.energizer.com/PDFs/nh15-2300.pdf>
>

Just curious - Do you ever have anything to write about that takes only 
one (not run-on) paragraph?

On 26/10/14 21.24, Glenn wrote:
...
> It is possible to buy battery BMS-controllers e.g.:
> * TI: bq20z60-R1, bq29330, bq294xy...
> * Atmel: ATA6870N *n +(ATmega32HVE2 or ATmega64HVE2)
>
> Atmel ATA6870N Li-Ion, NiMH Battery Measuring, Charge Balancing and
> Power-supply Circuit datasheet:
> http://www.atmel.com/Images/Atmel-9317-Li-Ion-Battery-Management-ATA6870N_Datasheet.pdf
>
>
> Look at the sources here:
> https://da.wikipedia.org/wiki/Batteristyresystem#Kilder.2Freferencer
>
> -
>
> There is even an interface standard (Smart Battery System, SBS):
> https://en.wikipedia.org/wiki/Smart_Battery_System
>
> A battery with a BMS is called a smart battery:
> https://en.wikipedia.org/wiki/Smart_Battery
>
> A charger that can "talk" with a battery with a BMS, is called a smart
> battery charger:
> https://en.wikipedia.org/wiki/Smart_battery_charger
>
> Glenn

Hi!

Forgot some smart battery charger chip examples:

AN667, microchip.com: Smart Battery Charger with SMBus Interface
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011076

-

Do not want to program your own Smart Battery Charger? - e.g. SBS 
compatible chips can be bought ready-made:

linear.com: LTC4100 - Smart Battery Charger Controller:
http://www.linear.com/product/LTC4100

linear.com: LTC4101 - Smart Battery Charger Controller:
http://www.linear.com/product/LTC4101

-

Please note: The "smarter" the more likelihood of incompabilities 
between the smart charger and smart battery:

batteryuniversity.com: : Inner Workings of a Smart Battery:
http://batteryuniversity.com/learn/article/inner_workings_of_a_smart_battery
Quote: "...
A speaker at a battery conference said, �The battery is a wild animal 
and artificial intelligence domesticates it.�
...
Ironically, the more features that are added to the SMBus battery and 
charger, the higher the likelihood of incompatibilities.
..."

Glenn

On 28/10/14 11.24, Glenn wrote:
...
> Hi!
>
> Forgot some smart battery charger chip examples:
>
> AN667, microchip.com: Smart Battery Charger with SMBus Interface
> http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011076

Now at:
http://ww1.microchip.com/downloads/en/AppNotes/00667a.pdf

> Glenn

On 10/27/2014 1:45 PM, John S wrote:
> On 10/26/2014 11:31 AM, Jeff Liebermann wrote:
>> On Sun, 26 Oct 2014 11:08:32 +0100, Robert Roland <fake@ddress.no>
>> wrote:
>>
>>> On Sat, 25 Oct 2014 20:45:38 -0700, Jeff Liebermann <jeffl@cruzio.com>
>>> wrote:
>>>
>>>> One accidental overcharge and your
>>>> battery is dead.
>>>
>>> Not true.
>>
>> I beg to differ.
>>
>>> Early NiMH batteries were quite intolerant of overcharging, but modern
>>> batteries are much more robust. Not quite as robust as NiCd, though.
>>>
>>> In fact, some amount of overcharge is necessary in order to keep the
>>> cells in a battery balanced.
>>
>> Let's see if I understand what you're saying.  In a series string of
>> NiMH cells, one must overcharge the good cells in order to bring the
>> not-so-good cells up to the good cell voltage?  Is that what you're
>> saying?  If so, this sounds like a variation on "battery conditioning"
>> which works well at killing batteries.
>>
>>
>> LiIon battery chargers have the same problem with series connected
>> cells.  The difference is that while NiMH cells might survive some
>> overcharge, LiIon cells short and die rather easily.  To solve the
>> problem of maintaining identical and balanced cell voltages, the RC
>> (radio control) industry uses a "balance charger":
>> <https://www.google.com/search?q=balance+charger&tbm=isch>
>> These have two connectors to the battery.  One pair of terminals for
>> the high current charge/discharge current, and another connector that
>> goes directly across each cell to monitor and control the charge
>> current for each cell individually.  Something like this might also
>> work with NiMH, but I haven't found any balance chargers that will do
>> it.  I suspect that's because LiIon and mutations are the future,
>> while the use of NiMH is decreasing rapidly.
>>
>> One of my experiments was to see how quickly I could fast charge NiCd
>> and NiMH cells.  Since these chemistries only get hot when
>> overcharged, I suspected that I could safely charge them at ridiculous
>> rates, as long as I didn't overcharge.  Trying to detect the 5mv drop
>> in terminal voltage at EOC was futile as warm contacts would ruin that
>> measurement.  Most cells were 2000 ma-hr AA NiMH cells that managed to
>> deliver about 1200 ma-hr at 1C discharge loads[1].
>> <http://802.11junk.com/jeffl/NiMH/Duracelll-NiMH-2050.jpg>
>> I would then quick charge them at up to about 5C (10 Amps) for about
>> 12-15 minutes.  Knowing the initial SoC (state of charge) and cell
>> capacity was critical.
>>
>> Of course, I intentionally overcharged some cells, just to see what
>> happened.  I determined that things change at about 75% of capacity.
>> Below 75%, the charging efficiency is 100%.  If I charged at any rate
>> to 75% of full capacity, I could discharge the cell (at C/10) and get
>> all of it back.  Above 75%, everything would change.  If I counted
>> coulombs and charged to 100%, the charging efficiency dropped from
>> 100% to about 85% with the loss going up in heat.  The heat was a
>> waste of charging energy.  It also caused the cell to deteriorate in
>> both capacity and self discharge rate.
>>
>> Notice that the cell does not magically stay cold at 99% of charge,
>> and explode at 101% of charge.  It's an exponential curve, that starts
>> at about 75% and climbs rapidly.  The 100% point seems to have been
>> selected to produce a reasonable number of charge cycles, safe
>> charging temperature, and approximate correlation with the -5mv NDV
>> (negative delta voltage) EoC point.  If you want your NiMH batteries
>> to live forever, just set the EoC to about 75% and don't go anywhere
>> near 100% charge.  I attempted to reproduce the NiMH graph at:
>> <http://batteryuniversity.com/learn/article/battery_performance_as_a_function_of_cycling>
>>
>> <http://batteryuniversity.com/_img/content/cycle3.jpg>
>> which shows loss of cell capacity after 300 charge cycles.  At 100%
>> charge (1C charge, 1C discharge, 4 hr cycle for about 100 days), using
>> a commercial smart charger, my results were fairly similar to the
>> graph.  However, at 75% of charge, there was little decrease in
>> capacity up to 700 charge cycles, when I gave up.  Unfortunately, I
>> discovered too late that my battery holder had a problem and that the
>> contact resistance had ruined my internal resistance measurements.
>>
>> Anyways, I think you can see what might happen as you approach 100%
>> charge with an NiMH battery.  I don't think going over 100% is a very
>> good idea.
>>
>> "Charging Nickel-metal-hydride"
>> <http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride>
>>
>>
>>
>>
>> [1]  NiMH cells are rated for capacity at C/5 discharge rate to 1.0v.
>> For a 2000 ma-hr cell, it takes about 10 hrs to run the discharge
>> test.  Typical data sheet:
>> <http://data.energizer.com/PDFs/nh15-2300.pdf>
>>
>
> Just curious - Do you ever have anything to write about that takes only
> one (not run-on) paragraph?

Hey, Jeff -

I apologize for that comment. It was rude and uncalled-for. The only 
excuse I have is that I had just had a bad experience and let my anger 
take control.

Sorry.

On Mon, 27 Oct 2014 13:45:06 -0500, John S <Sophi.2@invalid.org>
wrote:

>Just curious - Do you ever have anything to write about that takes only 
>one (not run-on) paragraph?

Nope.  I was a bit busy and didn't have time to make it brief.
(Apologies to Mark Twain).

I like to read detailed answers and try to provide the same.  I learn
more from these than from unsupported one line answers and short
quips, which are usually a waste of time.  My rule-of-thumb is that
anything I write should be something that people would want to read. I
don't think anyone wants to read one line retorts, which are the
fashion on Twitter.

>Hey, Jeff -
>I apologize for that comment. It was rude and uncalled-for. The only 
>excuse I have is that I had just had a bad experience and let my anger 
>take control.
>Sorry.

No problem.  I've done worse for much the same reason.  Had you found
one of my numerous mistakes and chronic math errors, I would have
responded with either apocalyptic fury or thanked you before
disappearing and going into a deep depression.

A few years ago, I was dealing with a kidney stone and was using
writing on Usenet to distract myself from the pain.  When not drugged,
I wrote with a general lack of coherence and in a tactless manner.
When drugged, much of what I wrote made no sense an hour later. Oddly,
my math and spelling improved when drugged.  My solution was to always
delay posting a reply, wait an hour, read it again, and then either
clean up the mess or just delete it.

I hope things work out for you.

-- 
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558