Two problems this past weekend

[WK154]

Actually brand has a lot to do with it. Notice the Duracell Copper-top outlasts the more expensive Quantum. The Costco and IKEA do quite well compared to the name brands. The difference in chemistry should be no surprise. The discharge curve has a significant bearing on life, some equipment can run at 0.9V others will die at 1.1V that could mean a couple of hrs.

[Wynnd]

I hadn't really thought about the charging aspect of NiMH.  I don't have much trouble with making sure the batteries get charged and I carry enough to run two shows without charging anything and still have an extra pair.  These are all good points.  (I hate the 9 volt NiMH.  Maybe some day, but not today.)

[sam.spoons]

Procell batteries are so cheap that I prefer peace of mind over saving a few pence. Even with 4 or 5 wireless mics the cost of batteries is less than a fiver per show, if that's a deal breaker you are in the wrong business.

[Wynnd]

I don't mind saving money, but I hate throwing things away when there is another choice.  Right now the band is rehearsing more than it's gigging out and the rehearsals are long enough that if the rechargeables were a problem, it would show up there long before showing up at a gig.  I fire them up before rehearsal and leave them on all the time.  No problem.  (Or at least a LOT FEWER problems than most guitarists have with broken strings.  By the way, I've never broken a bass string and I'm getting the impression that's a bit rare for someone who has been playing bass since 1972.)

[sam.spoons]

Agreed Wynnd, I wouldn't have a problem using rechargeables on my own band rehearsals were it not for the fact that I won't use wireless with my bands (it's an un-necessary complication which adds nothing to our show) but if I'm working for someone else, especially with large numbers of wireless mics (15 on Sweeney Todd) charging them would be a nightmare and the cost is passed on to the client anyway.

I'm a guitar player who almost never breaks strings BTW

[Wynnd]

The way I do my wireless is better than wired.  I have the receivers mounted in my mixing stack and already wired up.  So toss the batteries in the mic and turn it on.  Pretty easy to live with and about 2 minutes quicker than a wired mic.  Now 15 wireless mics can be a handful if you need to hook them up to the mixer every show.  (The situation of my Senior's variety show.  got that down to about 4 minutes for connecting the 14 color coded receivers.)

[Greg C.]

My experience with rechargeable batteries in wireless mics is that the two don't mix. New rechargeable don't last as long as standard batteries and aged ones can avalanche to low output unexpectedly and ruin a show. And no two rechargeables in the same batch seem to age at the same rate. Some start losing charge holding ability very fast. We had a local theater company here insist on trying them in their AT and Sennheiser headset packs and it was a disaster. And this was after months of experimenting during rehearsals with different brands of high end rechargeables. As sound designer, I finally insisted that they only use ProCell batteries from then on and to throw them away after every single performance. They agreed after several embarrassments. You can't fuck around with batteries in mission critical situations IMO.

[sam.spoons]

My experience with rechargeable batteries in wireless mics is that the two don't mix. New rechargeable don't last as long as standard batteries and aged ones can avalanche to low output unexpectedly and ruin a show. And no two rechargeables in the same batch seem to age at the same rate. Some start losing charge holding ability very fast. We had a local theater company here insist on trying them in their AT and Sennheiser headset packs and it was a disasters. And this was after months of experimenting during rehearsals with different brands of high end rechargeables. As sound designer, I finally insisted that they only use ProCell batteries from then on and throw them away after every single performance. They agreed after several embarrassments. You can't fuck around with batteries in mission critical situations IMO.

And the used ones will keep the crew in TV remote batteries for the rest of the year 

[Wynnd]

One more thing.  You have to keep alkalines in the original box or battery holder to prevent shorting.

[sam.spoons]

The same applies to rechargeable's (I have experienced the hot feel of a shorted PP3 in my change pocket only once, the much deformed battery still works, surprisingly), but, where else would you keep them anyway?

[Wynnd]

I bought some AA battery boxes at "The Container Store".  They have a double layer version with a moveable divider and a single layer with built in dividers.  (I use the single layer version in my mic box.)  I've got something similar for my AAAs but they power my remotes at home. 

[sam.spoons]

Sounds good, it would hold pro cells too, though as I was using box fresh batteries for every show it was simple enough to keep them in the box until use and discard them into a bucket at the end of the show. The used batteries were available for cast and crew to help themselves, batteries in mic transmitters were always changed by me or my assistant before every night/show (two shows on Saturday).

[WK154]

My experience with rechargeable batteries in wireless mics is that the two don't mix. New rechargeable don't last as long as standard batteries and aged ones can avalanche to low output unexpectedly and ruin a show. And no two rechargeables in the same batch seem to age at the same rate. Some start losing charge holding ability very fast. We had a local theater company here insist on trying them in their AT and Sennheiser headset packs and it was a disaster. And this was after months of experimenting during rehearsals with different brands of high end rechargeables. As sound designer, I finally insisted that they only use ProCell batteries from then on and to throw them away after every single performance. They agreed after several embarrassments. You can't fuck around with batteries in mission critical situations IMO.

My experience exactly for shows single use and toss. In my wife's case however in a non-mission critical classroom application, cost was the overriding factor. With a difference of 10:1 in price for quality NiMH : Alkaline break even for a 180 day school year was a no-brainer. The bigger problem was the attrition rate of batteries, the ones with legs for all those important electronic toys. The important thing with NiMH is to have a quality charger that can cycle and break in new ones such as a Maha MH-C9000 (~$50). The cheap ones are worthless. My wife retired before the batteries (~4 yrs use) and going.

[dpdan]

Another consideration of useless rechargeable batteries. AA batteries are 1.5 volts each, rechargeable AA batteries are only 1.2 volts, so a rechargeable can not compete for performance and run time.

[WK154]

Might want to look at this first before drawing that conclusion.
http://data.energizer.com/PDFs/nickelmetalhydride_appman.pdf
http://www.batteryshowdown.com/results-lo.html
http://www.foxhunt.com.au/misc/batteries/aa_batteries.pdf