rechargeable batteries and low volts
 

I would like people's opinions on using rechargeable batteries in wireless mic applications. The standards I've been used to are to not use them because they can have a marginally lower voltage which can hinder clean sound in a wireless tx'r and rx'r.

Has anyone had any long term experience using newer Ni-MH rechargeable batteries?

I was reminded of this issue because I've recently bought an Azden 500UDR and on page 7 of the user manual in full caps it says to not use rechargeable batteries.

http://www.azden.com/pdf/500udr-manual.pdf

This manual was also printed in 2001 before Ni-MH batteries were popular so I'm wondering if someone has insight as to whether this is a quality issue or an actual incompatability issue.

Thanks!

wes

I used NiMh batteries on a few jobs and found they work OK. The producer had them -- they were Radio Shack batteries.

He then bought a set of 200 mAH batteries (Accupower) that supposedly provide a full 9 volts. But the problem was the batteries wouldn't physically fit into the battery compartment of the Lectrosonic transmitters or receivers.

Thomas Distributing also sells Tysonic batteries, and they look like they might fit, but I hadn't received a response to my inquiry about size.

Also, I'm still looking for a charger that will handle eight batteries simultaneously.

Would be nice to use rechargeables and put an end to the growing stack of half-used 9v alkalines.

Dean Sensui
Base Two Productions

I've used them in the past , still do in a small LCD monitor. As for audio equipment, I stick with the good old "Duracell". As for 1/2 used batteries, I give them to my grandson for his toys. He can never have enough batteries!
I definately buy AA and 9V in bulk.
Don

thanks!
 

Thanks for the info guys!

wes

voltage differences
 

don't hold me to any of these numbers, but...it's my recollection that rechargeables are 1.2V and Alkalines are 1.4V. I've read advice from more than one person to change out batteries well before they are out because clean audio requires a battery in a high state of charge. If those comments were in regard to Alkalines, then perhaps there is greater potential for audio being adversely affected when using rechargeables that are somewhat old.

Rechargeable NiMH batteries (AA) are 1.2v and alkaline AA's are 1.5v. I've been using NiMH batteries, both AA and 9v, for over a year with no difficulties or degradation of my audio quality. The 9v are Varta brand batteries and fit my Lectrosonic gear.

Jeff,

What type of battery life do you get with the Vartas compared to Alkaline?

they have AA NiMH batteries over here that are around 1700 or some 2000mAh. So last a good while....would these not work better than standard AA cells that have a lot lower mAh???
The NiMH cells do produce a little bit of heat...but any possible damage cos of this, or you not noticed a thing with NiMH cells?

The problem is that NiMH cells have only about 1.2 volts per cell, quite a bit lower than the alkalines. So the longer power life may be offset by the lower starting voltage.

The life between NiMH and alkaline are actually about the same. I always change batteries during breaks etc. I don't do weddings, but the occasional speaker, lecture etc. They easily last a couple of hours.

I'd like to update this thread. At this point in time, large battery manufacturers such as Energizer and Sanyo are selling NiMH batteries
with the following capacities, although "minor" brands seem to sell
some with a higher capacity.

AAA 800/850 mAh (900 minor brand)
AA 2500 mAh
9v 170 mAh (200-250 minor brand)
C 3000 mAh (4500 minor brand)

Since this has been resurrected I thought I might add that if the manufacture recommends NOT using rechargables you must be careful and I suggest following their recommendations.
There are other differences in batteries that might not be apparent.
Alkalines have a limited CURRENT capacity that some recharables do not.
If the manufactures design uses this limited current flow as a cheat in their design you could damage electronics with the higher current capacity of rechargables.
This isn't to say it will happen only that it could.

NiMH & Wireless (radio) microphones
 

I have done some extensive testing of NiMH batteries with Sennheiser, AKG & Sony wireless mic's. The results can be viewed on my website at http://www.soundandmusicco.com/nimh.htm

Vinny,

This is great. THanks for doing it. From your findings it seems that for AA's the rechargables look the best option - but not so good for 9V. Could also be a considerable difference between brands and transmitters versus receivers.

Great stuff - thanks.