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.

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