... and I never ever use rechargables in radio packs.
ROn(UK)

Why? [if you wouldn't mind a newbie question...]
--
John English

John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)

Why? [if you wouldn't mind a newbie question...]

See my multiple posts on the subject. For most presentation purposes,
the proven reliability of the good old alkaline--fresh out of the
box--is superior. One less thing to worry about in a complex and
demanding environment.

The cost of having a show 'go down' is much more than that of fresh
cells...especially if the cost is losing your job.

jak

jakdedert wrote:
John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)

Why? [if you wouldn't mind a newbie question...]

See my multiple posts on the subject. For most presentation purposes,
the proven reliability of the good old alkaline--fresh out of the
box--is superior. One less thing to worry about in a complex and
demanding environment.

The cost of having a show 'go down' is much more than that of fresh
cells...especially if the cost is losing your job.


What he said. The risk just isn't worth it for the price of a few
batteries.
There`s also the factor that some low end radio mikes seem to object to
rechargable batteries (certainly nicads) It`s possibly the batteries
internal resistance changing as it discharges.
I`ve not really studied it, but when the rechargable discharges beyond
a certain point, the transmitters agc seems to get screwed up and
unstable, feedback is the result. Maybe someone with more technical
understanding can explain.

Ron(UK)

"Ron Johnson" wrote in message
...
jakdedert wrote:
John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)

Why? [if you wouldn't mind a newbie question...]

See my multiple posts on the subject. For most presentation purposes,
the proven reliability of the good old alkaline--fresh out of the box--is
superior. One less thing to worry about in a complex and demanding
environment.

The cost of having a show 'go down' is much more than that of fresh
cells...especially if the cost is losing your job.


What he said. The risk just isn't worth it for the price of a few
batteries.
There`s also the factor that some low end radio mikes seem to object to
rechargable batteries (certainly nicads) It`s possibly the batteries
internal resistance changing as it discharges.
I`ve not really studied it, but when the rechargable discharges beyond a
certain point, the transmitters agc seems to get screwed up and unstable,
feedback is the result. Maybe someone with more technical understanding
can explain.

Ron(UK)

You don't need much technical understanding to know that NiCd & NiMh
batteries have a lower terminal voltage.

ian field wrote:
"Ron Johnson" wrote in message
...
jakdedert wrote:
John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)
Why? [if you wouldn't mind a newbie question...]
See my multiple posts on the subject. For most presentation purposes,
the proven reliability of the good old alkaline--fresh out of the box--is
superior. One less thing to worry about in a complex and demanding
environment.

The cost of having a show 'go down' is much more than that of fresh
cells...especially if the cost is losing your job.

What he said. The risk just isn't worth it for the price of a few
batteries.
There`s also the factor that some low end radio mikes seem to object to
rechargable batteries (certainly nicads) It`s possibly the batteries
internal resistance changing as it discharges.
I`ve not really studied it, but when the rechargable discharges beyond a
certain point, the transmitters agc seems to get screwed up and unstable,
feedback is the result. Maybe someone with more technical understanding
can explain.

Ron(UK)

You don't need much technical understanding to know that NiCd & NiMh
batteries have a lower terminal voltage.


It`s not to do with the terminal voltage, it`s something to do with the
batteries internal resistance. Wireless packs are designed for
replacable batteries. The internal battery metering is calibrated for
Alkalines.

Remember the OP was talking 9v (PP3) batteries here, You're asking for
trouble using anything other than Procells or Energisers.

Ron

On Fri, 19 Dec 2008 16:13:13 -0000, Ron Johnson wrote:

ian field wrote:
"Ron Johnson" wrote in message
...
jakdedert wrote:
John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)
Why? [if you wouldn't mind a newbie question...]
See my multiple posts on the subject. For most presentation purposes,
the proven reliability of the good old alkaline--fresh out of the box--is
superior. One less thing to worry about in a complex and demanding
environment.

The cost of having a show 'go down' is much more than that of fresh
cells...especially if the cost is losing your job.

What he said. The risk just isn't worth it for the price of a few
batteries.
There`s also the factor that some low end radio mikes seem to object to
rechargable batteries (certainly nicads) It`s possibly the batteries
internal resistance changing as it discharges.
I`ve not really studied it, but when the rechargable discharges beyond a
certain point, the transmitters agc seems to get screwed up and unstable,
feedback is the result. Maybe someone with more technical understanding
can explain.

Ron(UK)

You don't need much technical understanding to know that NiCd & NiMh
batteries have a lower terminal voltage.


It`s not to do with the terminal voltage, it`s something to do with the
batteries internal resistance. Wireless packs are designed for
replacable batteries. The internal battery metering is calibrated for
Alkalines.

Remember the OP was talking 9v (PP3) batteries here, You're asking for
trouble using anything other than Procells or Energisers.

Designing anything for alkalines only in ths day and age is absurd.

P.S. rechargeables have LESS internal resistance. Try shorting a rechargeable and see how hot it gets.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

A beautiful young girl is about to undergo a minor operation.
She's laid on a trolley bed by a lady in a white dress and brought to the corridor.
Before they enter the room she leaves her behind the theatre door to go in and check whether everything is ready.
A young man wearing a white coat approaches, takes the sheet away and starts examining her naked body.
He walks away and talks to another man in a white coat.
The second man comes over and does the same examinations.
When a third man starts examining her body so closely, she grows impatient and says:
"All these examinations are fine and appreciated, but when are you going to start the operation?"
The man in the white coat shrugged his shoulders: "I have no idea. We're just painting the corridor."

Peter Hucker wrote:

Designing anything for alkalines only in ths day and age is absurd.


Show us some of your designs, troll.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

Peter Hucker wrote:


Designing anything for alkalines only in ths day and age is absurd.

In your opinion maybe. Professionals in the sound industry use quality
replaceable batteries, they are reliable - reliability means
_everything_ when a show (or your job) is at stake.


P.S. rechargeables have LESS internal resistance. Try shorting a rechargeable and see how hot it gets.

Try shorting a 9 volt Procell! stand well back tho...

Ron

In article .net,
John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)

Why? [if you wouldn't mind a newbie question...]

My answer would be is you can virtually guarantee the performance of a
decent make alkaline. And I sometimes use a great deal - my personal
record for number of radio mics is 38 at once. It really is rare to get a
faulty battery.

Trouble with rechargeables is they don't maintain the same performance
throughout their life - which makes knowing when they must be changed
rather hit or miss. Plus the fact that most give little warning of running
out - unlike an alkaline - due to the different voltage discharge curves.
So what might be a benefit on a high power demand device like a drill etc
is a liability on a low current one.

Of course if you know they will only be used for a short time - like say a
church service - rechargeables can and do make sense. But this isn't
usually the case for film, TV and conference etc use.

--
*Do infants enjoy infancy as much as adults enjoy adultery?

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

"Dave Plowman (News)" wrote in
:

Trouble with rechargeables is they don't maintain the same performance
throughout their life - which makes knowing when they must be changed
rather hit or miss. Plus the fact that most give little warning of running
out - unlike an alkaline - due to the different voltage discharge curves.
So what might be a benefit on a high power demand device like a drill etc
is a liability on a low current one.

All of which makes perfect sense - in the context of a NiMH or NiCd. As most
of this talk has gone to discussing microphones, consider a moderate steady
load. You want that to be supplied with equal constancy, if possible. If
nothing else you know what you'll get during the discharge if it IS constant
in voltage and has adequate current. Lithium ion cells do this fine. They
fall off at the end but not so fast as Ni-based cells. Actually the fade time
at end of discharge when powering a microphone should be fairly long, you'd
get early warning if you knew what to look for. You might still get a couple
of hours of use from start to end of fall anyway, if current demand is less
than 50 mA (examples below), given two CR123A cells. Total use is more than a
half a day easily, even with the lower 800 mAH capacity. With light loads the
safety is very good. Newer batteries even have the clout to power a drill, if
they have lithium titanate anodes. Their shelf life is actually BEST at
around 40% charge so they don't mind being left waiting around, and they can
be charged at any time. They store very well when cold so they won't mind
travel in an unheated truck. They work fine at sub-freezing temperatures too,
so long as you don't go too low, and not many things demand that of them in
use.

Time to running flat is long enough to give you the nice early warning you
can expect from alkalines, but is flatter for longer, before that happens.
And when you've charged them many times, the loss of capacity even after
hundreds of charges and a couple of years of use, will still give you better
performance after a charge, than an alkaline fresh out of the box. If you
charge them each night they'll probably never run flat, and as they'll spend
most of their lives at around 40% charge, give or take 40%, they should last
a long time.

If reliability is critical, run their first couple of charges in a non-
critical situation. Label them with coloured electricians' insulating tape to
code them, or whatever it takes to identify and organise. If I had to put
batteries in 100 microphones I'd rather use lithium ions than alkalines given
what I've seen of them so far on similar steady loads in critical situations
(hours in cold and darkness with a flashlight making the difference between
safety and injury).



http://web.telia.com/~u85920178/tx/bug.htm
http://www.zingsmusic.com/product_in...oducts_id=4483
(Two different systems, same 30 mA supply current, so I'm assuming it's a
good guide).
That said, this one takes 50 mA..
http://www.shure.com/ProAudio/Produc...us_pro_104c_ug

On Thu, 18 Dec 2008 00:08:20 -0000, Dave Plowman (News) wrote:

In article .net,
John E. wrote:
... and I never ever use rechargables in radio packs.
ROn(UK)

Why? [if you wouldn't mind a newbie question...]

My answer would be is you can virtually guarantee the performance of a
decent make alkaline. And I sometimes use a great deal - my personal
record for number of radio mics is 38 at once. It really is rare to get a
faulty battery.

Trouble with rechargeables is they don't maintain the same performance
throughout their life - which makes knowing when they must be changed
rather hit or miss. Plus the fact that most give little warning of running
out - unlike an alkaline - due to the different voltage discharge curves.
So what might be a benefit on a high power demand device like a drill etc
is a liability on a low current one.

Of course if you know they will only be used for a short time - like say a
church service - rechargeables can and do make sense. But this isn't
usually the case for film, TV and conference etc use.

Then use the new type of NiMH, the pre-charged ones which don't lose power sat on the shelf. Take them out the packet and they are as good as alkalines. Only keep them for a fraction of their life if you want a nice long charge, and put them in a trickle charger when not in use.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

"It is generally inadvisable to eject directly over the area you just bombed." - U.S. Air Force Pilot training manual

Peter Hucker wrote:

Then use the new type of NiMH, the pre-charged ones which don't lose
power sat on the shelf. Take them out the packet and they are as good as
alkalines. Only keep them for a fraction of their life if you want a
nice long charge, and put them in a trickle charger when not in use.


There are three problems with them. The first is that they are supplied
charged, but only about 80% charged. While they take longer to discharge
on their own, if they sit on the shelf for a year or so, they very well
may be flat.

The second is that they do not reach their full capacity when recharged
until they have been through 3 or 4 recharge cycles. I have found with
the ones I bought it took even longer, sometimes 10 cycles to get
any useful life out of them.

The third is that they have a higher internal resistance which limits their
output current. That is why the rechargeable alkelines that came out around
1995 never really took off. They were lower in capacity to the disposable
ones (about 80%) to allow room for expansion, and they did not put out
the current that nicads or regular alkelines did.

They also do not charge as fast. I charge mine in a 7 hour NiMH charger,
but have to do it twice. Using the little fixed rate charger that came
with a set, I have to charge then for at least 24 hours.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

On Thu, 18 Dec 2008 20:14:01 -0000, Geoffrey S. Mendelson wrote:

Peter Hucker wrote:

Then use the new type of NiMH, the pre-charged ones which don't lose
power sat on the shelf. Take them out the packet and they are as good as
alkalines. Only keep them for a fraction of their life if you want a
nice long charge, and put them in a trickle charger when not in use.


There are three problems with them. The first is that they are supplied
charged, but only about 80% charged.

I wasn't aware of that, although 80% sounds pretty good to me. You can always fill them before use (which is what we always used to do with the old type).

While they take longer to discharge
on their own, if they sit on the shelf for a year or so, they very well
may be flat.

The manufacturers claim they only lose 10% in a year.

The second is that they do not reach their full capacity when recharged
until they have been through 3 or 4 recharge cycles. I have found with
the ones I bought it took even longer, sometimes 10 cycles to get
any useful life out of them.

Odd, I've bought Eneloop and Hybrio and had nothing but perfection.

The third is that they have a higher internal resistance which limits their
output current. That is why the rechargeable alkelines that came out around
1995 never really took off. They were lower in capacity to the disposable
ones (about 80%) to allow room for expansion, and they did not put out
the current that nicads or regular alkelines did.

If you're using them in something that needs a high output current, I dread to think how much it's costing you in alkalines.

They also do not charge as fast. I charge mine in a 7 hour NiMH charger,
but have to do it twice. Using the little fixed rate charger that came
with a set, I have to charge then for at least 24 hours.

How long?!?!? I bought a Uniross FIFTEEN MINUTE charger. It charges them in 15 minutes *using a cooling fan) to 80%, then the final 20% in another 15 minutes.

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

"Flashlights are tubular metal containers kept in a flight bag for the purpose of storing dead batteries."

Peter Hucker wrote:

snip

Then use the new type of NiMH, the pre-charged ones which don't lose power sat on the shelf. Take them out the packet and they are as good as alkalines. Only keep them for a fraction of their life if you want a nice long charge, and put them in a trickle charger when not in use.


In a word; no.

We don't have trickle chargers in the truck that takes them to the next
city; nor the time to monitor their health. A new Procell is a 'known'
resource. It always works, IME. It always lasts about the same amount
of time. When it's exhausted (actually long before) we discard it--or
switch it to less demanding tasks--and grab a new one (which will last
exactly as long as the last one did). I have a box of used ones right
across the room. Want some? They're great for kids toys, flashlights,
portable radios etc.

You're not listening. Use them yourself if you want to. I value my job
and my reputation much higher than the price of a new battery...or a
thousand of them.

jak

On Thu, 18 Dec 2008 22:56:44 -0000, jakdedert wrote:

Peter Hucker wrote:

snip

Then use the new type of NiMH, the pre-charged ones which don't lose power sat on the shelf. Take them out the packet and they are as good as alkalines. Only keep them for a fraction of their life if you want a nice long charge, and put them in a trickle charger when not in use.


In a word; no.

We don't have trickle chargers in the truck that takes them to the next
city; nor the time to monitor their health. A new Procell is a 'known'
resource. It always works, IME. It always lasts about the same amount
of time. When it's exhausted (actually long before) we discard it--or
switch it to less demanding tasks--and grab a new one (which will last
exactly as long as the last one did). I have a box of used ones right
across the room. Want some? They're great for kids toys, flashlights,
portable radios etc.

You're not listening. Use them yourself if you want to. I value my job
and my reputation much higher than the price of a new battery...or a
thousand of them.

What will you do when they stop making them?

--
http://www.petersparrots.com http://www.insanevideoclips.com http://www.petersphotos.com

I had amnesia once -- or twice.