NiMH for wireless mics

[Dean Sensui]

In case anyone's interested in using rechargeable 9v batteries for their Lectrosonic (or other brand) wireless mics: I just picked up some Tysonic 9v 200 mAH batteries from Thomas Distributing.

These fit the rather tight tolerances of my Lectrosonic 185 transmitters..

Also picked up an MH-C1090F charger capable of charging 10 9v batteries at a time.

I just got these today but will follow up with notes regarding performance after a few jobs.

These batteries are supposed to have true 9v output and their capacity is higher than most other 9-volt cells. If they work as advertised, they'll pay for themselves after 20 jobs, and that includes what I paid for the charger.

Dean Sensui
Base Two Productions

[John Hartney]

Hi Dean,

I use nimh batteries in my wireless mics, wendt 4x mixer, hhb md500, and in my camera and frezzie dimmable on camera light. It's proven to be good chemistry for my uses.

Thomas distributing has been my source for some of the batteries and chargers. I've gotten some good prices on AA and AAA batteries in bulk from ebay sellers. Same as Thomas stocks at a lower price.

I only use lion batteries on my small dvcams pdx10, gl1, and sony dxc75.

No longer use nicads at all...

Best,

John

[Dean Sensui]

John....

I can't remember the last time I used NiCad batteries. As you have, I've switched all the rechargeables over to NiMH or LIon batteries. Of the NiMH AA's I originally bought the only ones I don't have are the ones I lost.

Did a few tests with my Lectrosonics 185 systems and got a good idea of how long they'll run.

According to Lectrosonics, the 185 system can be expected to perform as follows. It appears they do extensive testing as they mentioned that they tested the battery compartment's fit with more than 100 types of alkaline batteries.

With alkalines, here is the expected run times in hours:minutes.

Transmitter: 15:00
Reciever: 5:00


With 200 mAH NiMH here are the actual run times:

Transmitter: Not yet fully tested to the point where it shuts off. But extrapolated against tests done so far, it should be up 10.5 to 11.5 hours.
Reciever: 3:50

Nice to know that the transmitter can stand to run about 10 hours on NiMH batteries. It means that if the transmitters are worn as concealed bodypacks they won't have to be changed for the whole day. As for how they'll smell by then.... :-0

Dean Sensui
Base Two Productions

[Mike Butler]

John,
what NiMHs are you using on your Frezzi? Right now I am using a 3.6 AH lead-acid or a 7.2 AH lead acid for those long nights.

I feel a little awkward when I go through an airport and see that display case of items you can't bring aboard and there's a spittin' image of my lighting battery sitting next to the chainsaws, pipe bombs, etc. :-) Not that the TSA have ever stopped me from going through, however. I think they're too busy freaking out over my XL1 to notice.

[Gints Klimanis]

On the Thomas Distributing site, there are some 250 mAh 9V rechargeables by Ansmann. I haven't been able to find the company web site. Are these batteries for real?

[Mike Butler]

WOW...TEN batteries in 2 hours, no wonder that charger is soo popular with those wild and crazy paintballers! Too bad it won't do the 1.5V sizes like AA, C and D. I'm about to try NimH AAs in my Canon 420EX flash, but have so far used only throwaway batteries in it due to my prejudices about energy limitations of rechargeables.

[Gints Klimanis]

NiMH batteries deliver faster recharge times, which is very useful for me in indoor action sports. Although, if the flash level is very high, only the first shot in a series at 8 fps with my camera will be illuminated. When the flash level is lower, the flash keeps up for a couple hundred pictures over a period of an hour or so. I use five 2500 mAh NiMH batteries in my Nikon SB800 flagh. The downside of NiMH is that they lose capacity when they sit idle.
That's not a big deal Just charge them with a trickle charger the night before you need them. I've been using the RipVan Lighting 4000 charger, but due to greater power demands, I've ordered the Ansman 16 .

[Gints Klimanis]

In case anyone is concerned about tight tolerance of 9V NiMH batteries, I'm
using the Maha PowerEx 9V batteries in my Sennheizer Evolution 100 wireless microphone. They fit with no difficulties.

[Gints Klimanis]

>WOW...TEN batteries in 2 hours, no wonder that charger is soo popular with >those wild and crazy paintballers! Too bad it won't do the 1.5V sizes like >AA, C and D.

You can try the ANSMANN Deluxe "Energy 16 NiMH Battery Charger" from Thomas Distributing. It charges quickly, but man, it cooks the batteries.
I bought a unit, and the AA battery casing bubbled the next morning. I thought it was a smart charger, but "smart" in this case is comparable to the intelligence of a refrigerator.

Seriously, the best charge and longer battery life is reportedly reached with slower chargers and advanced trickle chargers. I really like the LA CROSSE BC-900 Battery Charger, but it is kinda bulky with the external power supply and cord. Also, it only does AA and AAA, though it does come with some plastic cases which house AA's to give you fake size C and D batteries.
This battery charger has a programmable charging current, which is a slow, complete charge at 200 mA. The batteries are never hot. If you need faster charging time, just tap the current switch until you get the higher current you want.

[Gints Klimanis]

Also, I'm using the MAHA MH-C490F "9V" 4 Channel Multi-Channel Smart Charger with the PowerEx 9.6 Volt NiMH Rechargeable Battery .

http://thomas-distributing.com/maha-...ry-charger.htm

It seems like a basic charger to me, and it did have trouble with one of my five 9V batteries. Does anyone know of a "smarter" 9V charger that can drain and recharge batteries with the push of one button ?

[Gints Klimanis]

I liked this article :

Got Juice? Not for Long, You Don't.
In the escalating arms race between battery power and consumption, The Cells are losing to The Gadgets—Big time. Question is, can the chemists catch up to the engineers?

http://www.popsci.com/popsci/technol...cbccdrcrd.html

----------------------------
Here is some more good text from the printed article that is not included
in the on-line version.
Alkaline Disposables
--------------------
They still exist because of convenience, not chemistry.
You can buy them - for pittance - from New York to Nepal.
Perfect for occasional use devices, such as smoke detectors
and TV remotes, because of their long shelf life.

Nickel Cadmium (NiCd)
---------------------
Good for 1000 discharge cycles. They're toxic and
suffer "memory effect" when damaging crystals from if
the cell isn't often fully-discharged. NiCds are rare
except in power tools. their high discharge rates suit
big-current draws.

Nickel-Metal Hydride (NiMh)
---------------------------
Higher energy density than NiCds but only last up
to 500 discharge cycles. Must be fully discharged monthly
to preserve strength. Leading chemistry for rechargeable
AA and other standard-size cells. Relatively non-toxic.

Lithium-Ion (Li-ION)
-------------------
Unbeatable for energy density. Up to 1000 discharge
cycles with no memory effect, so don't require discharging.
Currently, the leading chemistry for laptops, camcorders,
cell-phones and portable gadgetry.

Lithium-Ion Polymer
-------------------
Variation on Li-ion chemistry introduced in 1999. Solid,
polymer innards of cells allow designers to mold battery into
odd shapes so that they can squeeze it around components,
maximizing capacity.

[Vinny Osborne]

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

[John Hartney]

Mike Butler,

Sorry it's taken me 2 years to reply :-) but since I see this thread has been brought back to life -

I use an IDX H50DX
Capacity: 50Wh/3.8Ah
Mean output voltage: 14.4V~13.2V
Maximum output voltage: 16.8V
Typical Camera run time: 1.9 hours (@26W)
Protection circuit: Temperature and current voltage protection
Operating temp: 32°F~86°F, -0°C~30°C
Dimensions: 7.28"(W) x 2.83"(H) x 0.98"(D)
185mm(W) x 72mm(H) x 25mm(D)
Weight: approx. 1.32 lbs. (600g)

It alone powers the Frezzi minifill with dimmer, having power exclusive to the battery and camera was a goal when I set this up. The camera mount has the powertap, so I could use the camera batteries, but I choose not to. LiOns don't like high discharge rates. I use the frezzie np1 holder on the back of an idx endura idx LiOn that powers the camera. I did need to get a special bracket to go from np1 mount to v mount, but they are readily accessible.

When I get two idx 50's, the np1, and a wireless reciever haning off the back it is a lot of hardware, but it balances well with the Canon 18x on the front of my Ikegami DV7 which I use this setup with.

[Mike Butler]

Originally Posted by John Hartney

When I get two idx 50's, the np1, and a wireless reciever haning off the back it is a lot of hardware, but it balances well with the Canon 18x on the front of my Ikegami DV7 which I use this setup with.

Yes I would agree it is a lot of hardware...do you have a picture of this backend? I could probably use that kind of ballast for my perennially nose-heavy XL1 (wouldn't mind giving it up for a nice Ike) heh heh

[Gints Klimanis]

Originally Posted by Vinny Osborne

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

Vinnie,

Thanks for the tests. I'm a little disappointed that my PowerEx 9V 200 MAh
cells didn't rate that well. I kinda figured the other cells would have fake specs and actually perform slightly worse. Doh !