Hello. I'm investigating using rechargeable with a pair of diversity
wireless microphones. I believe that they are A-T; I will check the
model number in the next day or two.

From looking through some NG archives, it looks like the Maha/Powerex
200mA 9.6V batteries paired with their 10-channel charger would be a
good choice.

Questions:

1. Has the NiMh technology gotten to the point where I can expect that
I can get close to alkaline reliability?

2. Is the above manufacturer a good choice? Any other recommendations?

3. I plan to manage/track the charge/recharge cycles. Is 500 cycles a
reasonable target for the batteries before I cycle them out?

4. Is there any means of predicting when I will have a failure on any
particular battery?

5. Any other caveats/warnings/advice on how to have the rechargeables
work reliably?

6. Recommendations for a supplier?

TIA.

--phil
(If you wish to e-mail, use the host kaosol dot net rather than the
one in the header).

"Phil Earnhardt"


1. Has the NiMh technology gotten to the point where I can expect that
I can get close to alkaline reliability?


** Please define reliability ?

Normal alkalines only have one discharge cycle and a very long shelf life.


BTW

Are you not concerned about the run time ?

An Energiser 522 will likely run nearly twice as long as that 200mAh
Ni-MH.

http://data.energizer.com/PDFs/522.pdf



....... Phil

On Mon, 23 Jan 2006 17:50:09 +1100, "Phil Allison"
wrote:

1. Has the NiMh technology gotten to the point where I can expect that
I can get close to alkaline reliability?


** Please define reliability ?

Somewhere north of 99% the time there would be no battery-related
failure.

Normal alkalines only have one discharge cycle and a very long shelf life.
BTW

Are you not concerned about the run time ?

Of course. I'm looking for runtimes of around 3 hours.

An Energiser 522 will likely run nearly twice as long as that 200mAh
Ni-MH.

http://data.energizer.com/PDFs/522.pdf

And what is the nominal run-time one should expect to have with a
typical diversity wireless transmitter?

--phil

"Phil Earnhardt"
"Phil Allison"

1. Has the NiMh technology gotten to the point where I can expect that
I can get close to alkaline reliability?


** Please define reliability ?

Somewhere north of 99% the time there would be no battery-related
failure.


** No battery type has reached that exalted level.

More than 1% of alkalines are duds out of the pack.



An Energiser 522 will likely run nearly twice as long as that 200mAh
Ni-MH.

http://data.energizer.com/PDFs/522.pdf

And what is the nominal run-time one should expect to have with a
typical diversity wireless transmitter?


** Try asking a question that you actually need a reply too.

Leave dumb hypotheticals out.




.......... Phil

I can understand wanting to save money, but NiCad and NiMH batteries show an
abrupt voltage drop at the end of charge. This is _not_ what you want when a
performer is depending on a cordless mic!

The battery's capacity has to be enough to power the mic for the time you
intend to use it. And, as the battery's capacity will decline with usage,
its initial capacity has to be substantially greater than what's "needed",
or the useful life of the battery will disappointingly short.

"William Sommer******"


I can understand wanting to save money, but NiCad and NiMH batteries show
an
abrupt voltage drop at the end of charge.


** Err - this ought to be *discharge*, not *charge*.


This is _not_ what you want when a
performer is depending on a cordless mic!


** Nonsense. Radio mics have internal voltage regulators that shut the mic
down very abruptly with any type of battery.

This is done to make *sure* the mic stays *on frequency * during operation.


The battery's capacity has to be enough to power the mic for the time you
intend to use it.


** Certainly true.


And, as the battery's capacity will decline with usage,


** How ambiguous.

Maybe "usage" should have been "cycling" ????


its initial capacity has to be substantially greater than what's "needed",
or the useful life of the battery will disappointingly short.


** Where NiMH batteries are to be used in a radio mic - spares MUST be
always available. The spare MUST be installed after a few hours use if
experience shows that end point is close.

The beauty of using an alkaline is that it will typically last long enough
not to worry about the time.



.......... Phil

For what it is worth, I have made quite a few service calls to
customers that complain of their wireless mics are not functioning
properly. The most common answer is rechargable batteries. We install
new alkaline batteries, make them swear to never use rechargables and
we have no more complaints.

You can buy them fairly cheap if you buy them by the box at a Costco,
Sams or professional tape company.

Good Luck,
Doc

"Phil Earnhardt" wrote ...
And what is the nominal run-time one should expect
to have with a typical diversity wireless transmitter?

Woudn't it be nice if the world were that simple. There
is no "diversity wireless transmitter". Only receivers
are "diversity". Transmitters know/care nothing about
"diversity".

There is no "typical" either. If you want to know how
long a particular brand/model battery works with YOUR
transmitter, run the exeriment. Note that different brands
and different models of batteries will perform differently
in your transmitter.

Note also that because of their intrinsic chemistry,
rechargable batteries tend to have lower voltage (even
when "full") than primary batteries and lots of equipment
doesn't perform as well (or as long) with rechargable.

Over on rec.arts.movies.production.sound are many
pros who do sound for the movies/TV shows we see
every week. They discuss wireless mics and batteries
there almost weekly. Suggest doing an archive search
http://groups.google.com/advanced_group_search?hl=en
There are many hours of very informative reading there
on the topic of wireless transmitters and batteries of
different kinds. There are also 1 or 2 wireless equipment
manufacturers represented there. One of them just ran
the experiment with a couple of new brand/sources of
batteries that someone discovered.

"Doc Weaver" wrote ...
For what it is worth, I have made quite a few service calls to
customers that complain of their wireless mics are not functioning
properly. The most common answer is rechargable batteries. We
install
new alkaline batteries, make them swear to never use rechargables and
we have no more complaints.

You can buy them fairly cheap if you buy them by the box at a Costco,
Sams or professional tape company.

Indeed, over on rec.arts.movies.production.sound they
are perpetually on the lookout for cheaper (but reliable)
sources of batteries. They are in a high-stakes game with
big-name talent using their wireless mics and they don't
trust rechargables as a rule. They virtually all use primary
batteries from a reliable source.

Phil Earnhardt wrote:

On Mon, 23 Jan 2006 17:50:09 +1100, "Phil Allison"
** Please define reliability ?

Somewhere north of 99% the time there would be no battery-related
failure.

Phil, use Duracell "Procells". They have product specs exactly
the same as the regular Duracell Alkalines, but according to Network
guys Duracell Procells have better quality control, and as they come in
bulk packaging they are cheaper too. There is no need to reinvent the
wheel, that's what most everyone in TV and movies use because it is the
most reliable. If you save $5 a gig by using rechargables and blow the
gig, you haven't saved anything.

Are you not concerned about the run time ?

Of course. I'm looking for runtimes of around 3 hours.

An Energiser 522 will likely run nearly twice as long as that 200mAh
Ni-MH.

http://data.energizer.com/PDFs/522.pdf

You can get a solid 3 1/2 hours with most RF's I have used (Sony's,
Sennheisers, Vegas) but after that you will start to take "hits" if you
work in an area with a lot of RF traffic. See, the RF up the block
will walk on down to you and smack your receiver around and, like weak
Diner coffee your transmitter won't be strong enough to defend itself.


Spend the money, and don't go to rechargables until they come up
with something reliable enough that all the TV Network and Movies guys
use them everyday (and that covers your butt somewhat if things fail
somehow.) If it's a critical gig, check your battery voltage even when
they are fresh out of the box. I have come across a box or two of
Procells in the last 9 years that were bad and below 9 volts, and
they're the good ones. Some guys do use rechargables for IFB
receievers though, as it takes less power to run one of those than to
power a trahnsmitter.

Will Miho
NY TV/Audio Post/Music/Live Sound Guy
"The large print giveth and the small print taketh away..." Tom Waits

BTW, these guys seem to have great prices....
http://www.batterywarehousedirect.com/2.html


Will Miho
NY TV/Audio Post/Music/Live Sound Guy
"The large print giveth and the small print taketh away..." Tom Waits

Just don't do it. Alkalines are flaky enough. If anything, I would
suggest trying the Ultralife 9V lithiums. They aren't rechargeable
either but have much longer operating life as well as a longer shelf
life.

If your problems are due to the talent leaving his pack on when he
should have turned it off, that's another issue, and one that cannot
be solved by cheaper or rechargeable batteries.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
Just don't do it. Alkalines are flaky enough. If anything, I would
suggest trying the Ultralife 9V lithiums. They aren't rechargeable
either but have much longer operating life as well as a longer shelf
life.

Ditto, Ditto, Ditto...with a capital 'D'.

If your problems are due to the talent leaving his pack on when he
should have turned it off, that's another issue, and one that cannot
be solved by cheaper or rechargeable batteries.

....but which can be solved with a case of fresh batteries and eternal
vigilance. I never rely on 'talent' to wrangle their own transmitters.
I either use the 'lock' function on the transmitter, if it has one--or
gaff tape--to lock all transmitters *on* and change batteries every
chance I get.

Expecting talent to manage their own belt packs is a much more sure
invitation to *silence*--when there's supposed to be dialog--than dead
batteries.

jak
--scott

Using rechargables with wireless transmitters

Group: rec.audio.pro Date: Mon, Jan 23, 2006, 6:48am (EST-3) From:
(Richard*Crowley)



Over on rec.arts.movies.production.sound are many pros who do sound for
the movies/TV shows we see every week. They discuss wireless mics and
batteries there almost weekly. Suggest doing an archive search
http://groups.google.com/advanced_group_search?hl=en There are many
hours of very informative reading there on the topic of wireless
transmitters and batteries of different kinds.


There are also 1 or 2 wireless equipment manufacturers represented
there. One of them just ran the experiment with a couple of new
brand/sources of batteries that someone discovered.

That would be Lectrosonics who found that the best time to complete
failure was 5 hrs for rechargeables & alkalines. De facto standard is
to change batterys at most every 4 hrs in tx's at 50mw and 100mw output
if on continously.

Eric

"Eric Toline" wrote in message
...

Using rechargables with wireless transmitters

Group: rec.audio.pro Date: Mon, Jan 23, 2006, 6:48am (EST-3) From:
(Richard Crowley)



Over on rec.arts.movies.production.sound are many pros who do sound for
the movies/TV shows we see every week. They discuss wireless mics and
batteries there almost weekly. Suggest doing an archive search
http://groups.google.com/advanced_group_search?hl=en There are many
hours of very informative reading there on the topic of wireless
transmitters and batteries of different kinds.


There are also 1 or 2 wireless equipment manufacturers represented
there. One of them just ran the experiment with a couple of new
brand/sources of batteries that someone discovered.

That would be Lectrosonics who found that the best time to complete
failure was 5 hrs for rechargeables & alkalines. De facto standard is
to change batterys at most every 4 hrs in tx's at 50mw and 100mw output
if on continously.

Eric


Wasn't the most recent test for some Lo-cost Lithiums (non-rechargable) vs.
Alkalines? The Lithiums, higher cost than Alkalines, had no advantage.

Steve King

Using rechargables with wireless transmitters

Group: rec.audio.pro Date: Mon, Jan 23, 2006, 12:15pm (EST-1) From:
(Steve*King)
"Eric Toline" wrote in message

That would be Lectrosonics who found that the best time to complete
failure was 5 hrs for rechargeables & alkalines. De facto standard is to
change batterys at most every 4 hrs in tx's at 50mw and 100mw output if
on continously.
Eric

Wasn't the most recent test for some Lo-cost Lithiums (non-rechargable)
vs. Alkalines? The Lithiums, higher cost than Alkalines, had no
advantage.
Steve King

I'm not sure about the non-rechageable part but other than that, you're
correct.

Eric

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Will wrote:
You can get a solid 3 1/2 hours with most RF's I have used (Sony's,
Sennheisers, Vegas) but after that you will start to take "hits" if
you work in an area with a lot of RF traffic. See, the RF up the
block will walk on down to you and smack your receiver around and,
like weak Diner coffee your transmitter won't be strong enough to
defend itself.
Spend the money, and don't go to rechargables until they come up
with something reliable enough that all the TV Network and Movies
guys use them everyday (and that covers your butt somewhat if
things fail somehow.) If it's a critical gig, check your battery
voltage even when they are fresh out of the box.
I wholeheartedly agree. I'd also like to add that alkalines
save you some hassle with your assistants. IF you travel to
the gigs you've got to remember to put the rechargeables on
chargers when you get back to base and take them off when
they're done charging or buy smart chargers. THere's
accounting for them, making sure they're charged before you
go out for the next one, etc.
All the rechargeables in the world won't help you save money
if they didn't get charged properly after the gig, and even
if you work by yourself you might forget until next gig.

NOt quite related, but here's what I found when working with
the hospital people during Katrina. sEcurity had purchased
some new Motorolla 800 megahertz portables, one rechargeable
nicad pack per unit. NOW the problem comes in when these
guys come off shift and just stick their walkie in the
charging stand. Of a sudden during Katrina when security
needed those radios they were dropping like flies. WHy?
because the batteries had not been properly cared for. I
was talking with the head of security and told him that net
time he should order a spare battery pack for each portable.
YOu go out on shift, take your walkie, take a spare battery.
WHen your battery goes down for the count, return to base,
put battery on charger. Put spare battery on portable.

I get long life out of my rechargeable packs for my portable
vhf/uhf unit and the wife's because we properly care for
batteries. rUn them clear down before recharging, charge
them and then use them. IN fact my lady uses her portable
less often than I. THerefore I take the battery she's
actually using and trade with her and draw it the rest of
the way down. SHE carries a vhf/uhf amplifier in the van
and powers the portable with the internal battery because
it's one less umbilical cable.
Rechargeables are a headache you don't need. DOn't know
what your application is, but it's another task for your
crew that can get screwed up and leave you hanging in the
breeze on a crucial gig. BUy alkalines, use 'em and pitch
'em. STart every gig with a fresh battery in every wireless
tx unit.




Richard WEbb,
Electric SPider Productions
Replace anything before the @ symbol with elspider for real
email address.



braille: support true literacy for the blind.

change batterys at most every 4 hrs in tx's at 50mw and 100mw output if
on continously.

Or: Change batteries at the start of every set, or every other set. (If
you can't remember when you changed the batteries, change the batteries!)

The Lithiums, higher cost than Alkalines, had no advantage.

Lithiums have advantages under specific kinds of load. I wouldn't expect
a small transmitter to suck on them hard enough to make that difference
noticable.

Joe Kesselman wrote:
change batterys at most every 4 hrs in tx's at 50mw and 100mw output if
on continously.

Or: Change batteries at the start of every set, or every other set. (If
you can't remember when you changed the batteries, change the batteries!)

The Lithiums, higher cost than Alkalines, had no advantage.

Lithiums have advantages under specific kinds of load. I wouldn't expect
a small transmitter to suck on them hard enough to make that difference
noticable.

The advantage of the lithiums is the enormous shelf life. If you only
use the unit irregularly, it's good to know you can pick it up and the
batteries will be still fine after being on the shelf a couple years.

A smaller advantage is the higher capacity... most equipent will run about
three times as long on the Ultralife lithiums as on alkaline batteries.
On the other hand, if you're paying five times as much, this is not a
real improvement.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."