Wanted to get recommendations with regards to what's the best AA batteries to use when working with my G2 wireless lav.

I've discovered that my 2400NiMH AA Recargeable are causing a fuzzy distortion as compared to using the supplied Varta Alkaline batteries. It seems that even though they are fully charged, they aren't providing the output necessary to get a clean signal as compared to the disposable ones that came with the G2 kit.

I try to practice not using disposable anything unless I absolutely have to - is this one of those times where standard alkaline AA's are necessary or are there rechargeable AA's out there that someone would recommend to use with the Sennheiser G2 setup?

No idea how you're getting fuzzy distortion.. I've used both Energizer Rechargeables and regular alkaline batteries with no issue. What other batteries have you tried?

I don't remember where I read it, but I read that rechargeable batteries only supply 3/4 of the voltage that a regular AA does. I can tell you that I can't use freshly charged batteries in my R4 but the dame batteries will fire my flash almost all day. Regular AA's will power it just fine. Whatever the reason, using rechargeable batteries in a wireless system isn't recommended.

Mike

I don't remember where I read it, but I read that rechargeable batteries only supply 3/4 of the voltage that a regular AA does. I can tell you that I can't use freshly charged batteries in my R4 but the dame batteries will fire my flash almost all day. Regular AA's will power it just fine. Whatever the reason, using rechargeable batteries in a wireless system isn't recommended.

Mike

Mike - Your response seems to confirm my findings - I used the provided Varta Alkaline's and the audio sounds great - I put in my freshly charged Duracell 2400mAh NiMH's and the audio gets fuzzy...

Unless someone can prove otherwise, I guess it's disposables.. :-|

Dear Cliff,

Good, fresh, alkaline AA batteries usually have an initial voltage of over 1.5 volts. I typically measure around 1.56 volts using Energizer non-rechargeables. Please note that good alkalines keep their charge much longer than rechargeables, which self-discharge fairly quickly if not used.

Good, fresh, just off the charger (taken off of the charger soon after the charge cycle is complete), Energizer NiMH batteries measure around 1.40 volts. I consider 1.38 volts and above to be fine. If you leave them on most chargers after the charge cycle is complete, then they will have lost some of their charge.

The key here is that many NiMH batteries lose their charge quickly.

I always try to measure the voltage of my batteries before I use them, and always charge them the night before, or the day before, a shoot. It is easy to tell the best, from the good, from the weak, using a good voltmeter.

If you do not have (and do not want to get) a good digital voltmeter (and they do not cost much), then the battery gauge on the Sennheiser G2 units does a great job.

If you put fresh alkaline batteries in a G2, the battery gauge will read completely full.

Freshly charged good NiMH batteries will also read completely full, but not for long. But do not worry. There is still plenty of charge left in the NiMH to power the G2's for many hours.

So, I would like to know what your G2 battery gauge is indicating when you have the fuzzy distortion.

Energizer recently came out with a new type of NiMH battery that has slightly lower rated capacity, but does not lose the charge as quickly.

I have never had the fuzzy distortion that you are reporting. The difference between the 1.56 volts and the 1.40 volts is not significant. As the batteries are used, both will go down in voltage.

Could you please report:

1. How many bars you are seeing in the Sennheiser G2’s battery gauge, and
2. What batteries (Brand, rated capacity in MAH (milliamp hours), and
3. Type (alkaline, or rechargeable) you are using, when you hear the distortion?

4. Do you charge your rechargeables within 1 day of using them?

I work with radios quite a bit, and despite rechargeables making economic sense, there's nothing as reliable as a bog standard alkaline cell. I mainly do theatre shows, one set per show, so have a pretty permanent supply of half empty ones for kids toys, and other non-critical things. Oddly, after three hours, they won't power my Pentax!

It isn't battery life on rechargeable ones, it's reliability. Can you be certain the ones you put in were on charge overnight, or did somebody swap them, or have you just put the almost dead ones in (the quick on/off - check meter, often shows full for a minute or so). Just to scary, so we carry on buying alkalines in bulk.

Dan - These are a set of 4 Duracell 2400mAh Rechargeables - the battery indicators on the G2s showed one bar missing from full charge as compared to the alkaline's which showed all bars.

With the Varta Industrial Alkaline's that came with the G2 kit, the mic sounds crystal clear. With the freshly charged NiMH Duracells, the audio has a distinct fuzzy distortion in general, and is very noticeable when I was speaking into the mic at a normal level. The audio levels on my HC7 were set to manual and adjusted to approx -6 to -10db so as far as I could tell, there was no over-modulation taking place.

Dear Cliff,

I use the Energizer 2500 MAH batteries.

Some are less than 1 year old, others are over 2 years old.

They all seem to work well.

I follow the steps I outlined above.


If you leave G2 on, with the rechargeable batteris in question, does the battery gauge go down quickly, say in an hour or two.


I have never had a problem with distortion.


Energizer indicates in their advertising that their rechargeables have more power than regular alkalines. I have not run any tests, but 3 of them power my Sound Devices Mixer for a long time.

Dan - maybe what I need to do is just get a dedicated set of these rechargeable batteries for the wireless lav.

Is there a difference between the standard overnight rechargeable's and the quick charge batteries (they charge between 20 minutes to 2 hours).

Also - do you have the actual model name for these batteries you are referring to?

Dear Cliff,

I currently use the 2500 MAH batteries. I do not have a part number, but here is a link:

http://www.energizer.com/products/hightech-batteries/rechargeables/Pages/rechargeable-battery-charger.aspx

I use the slow chargers (they are easier to find in stores and cheaper).

I have never used the fast chargers.

I would like to know if the fast chargers, which heat up the batteries, actually hurt the batteries or not.

I buy the charger, with 8 AA's and 4 AAA's in a package.

I'm wondering if maybe quick chargers sacrifice full charge for quick turnaround on charging itself. I have wall mount chargers that take 24 hours or so to fully charge batteries, I"m wondering if the quick charger I have been using is the culprit.

I'll do some more testing to see if this is the case - I'd prefer not using disposables since reuse helps protect the environment and is a core mission statement of my work.

Also - I've discovered that their are higher mAh batteries available (2700 and 2900) - would these provide more power for longer periods???

Dear Cliff,

The user manual, available on-line, for the 15 minute charger states that you can leave the batteries on the charger for an additional 10 minutes to provide an even fuller charge. (I do not remember exactly how it is worded.)

The manual says that the batteries will get warm. I believe that this is an understatement.

The 15 minute charger has advantages in that it can be powered from a 12 volt source, such as a car, or normal AC power.

http://www.energizer.com/SiteCollectionDocuments/pdf/rechargeable/ch15mn_instructions_english.pdf

I wonder if these batteries have been left uncharged for too long and they just aren't holding a good charge. I've got a set charging right now and will know tomorrow

Dear Cliff,

Based on the information that you have provided, I believe that you have a problem specifc to your batteries.

In other words, I feel that other rechargeable batteries can and do work well with the Sennheiser G2's.

Thanks Dan for your input - I'm off today to purchase a dedicated set just for the wireless lav.

Dear Cliff,

I found this quote on the Energizer website, under the FAQ's.

"In general, fast chargers can limit the NiMH battery lifetime to 150 charges while slower chargers can prolong the cycle life to more than 500 charges"

NiMH cells are 1.2V compared to Alkaline's 1.5V. That can cause problems with some gear however Sennheiser do supply an optional battery and charger for the G2s that uses 2x NiMH cells so the units should work just fine with 1.2V cells, certainly the 8 that we have do. Due to the lower voltage the indicator on the units may show one bar short of full capacity even with a fully charged battery.

In general the slow chargers are not recommended for high capacity NiMH batteries, the charging logic uses dv/dt and temperature to determine charge status, if you charge them too slowly then the dv/dt might not happen or not be detected and the batteries will be overcharged.

NiMH batteries over 2100mAH do self discharge faster however the difference is measured in weeks not days. I think it's Sanyo who first came out with a NiMH cell specifically designed for low self discharge. They're mostly targetted for use in remote controls that draw such little power that the self discharge current would be greater than the current drawn by the device itself.

If a G2 is soundy fuzzy running off NiMH cells it's possibly faulty. Try to determine if it's the transmitter or the receiver or even the mic. This kind of fault could easily be overlooked during production testing.

I should mention perhaps that the G2 handheld wireless mic will not run off NiMH batteries, it will not even power up however I don't think you can even fit Sennheiser's NiMH battery pack into that unit so it's almost certainly by design.

That makes perfect sense to me - I'll go back to using my standard chargers then and get the batteries today

Bob - I tested the unit with the Alkalines provided in my G2 kit and the mic worked fine so I'm deducing it's the rechargeables causing the problem - these have been left uncharged for a long time and I'm guessing they aren't holding much of a charge.

Here's the rub: I can put new, 2750 mah batteries into my R4 and if it powers up, it won't be for long. I can put the same batteries into a Canon 580 flash, discharge at full power and my recycle time is approx. 5 seconds and the batteries will go all day. If I put alkaline batteries in the R4 I am good to go for a few hours. I can repeat the above any day of the week with any rechargeable. Moral of the story: there is most definitely a difference in how some gear responds to or how the rechargeable delivers power to the gear. Given this, why would I want to risk using rechargeable batteries on a shoot? And to tell the truth, I am not sure how much I am "saving" using rechargeables. I can get Duracell Pro alkaline's for .40 a pop. When they won't power my G2, they will power my remotes. We use the rechargables in camera flashes for the short recycle time- but a 10-pack is $25 and they generally last about a year before recycle times diminish and I start all over again.

Anyway, I would not trust rechargables in any of my audio gear.

Mike

Apparently Sennheiser trusts them: http://www.bhphotovideo.com/c/product/324393-REG/Sennheiser_BA2015G2_BA_2015G2_Rechargeable_Battery.html

I've been doing some studio shooting for one of my clients, using their gear, and they have two G2 systems and use rechargeable batteries with no trouble. They're not like the above, but the batteries say "industrial." I guess maybe there's a difference between the cheapo consumer batteries and charger and the heavier duty ones.

I have had great success with the Energizer rechargeables.

I follow the rules outlined above.

While they are spec'ed as 1.2 volt, they are almost always above 1.38 volts when they come off of a charge cycle. If they have been abused, then the voltage will be lower.

I have quite of few sets of Sennheiser G2's, both the regular and the "Plug-On Transmitters", both Series 100 and Series 500.

All work extremely well with the Energizers.

During very long shoots, over 10 hours, I replace the batteries, if they start to get low, as indicated on the G2's battery gauge.

Since I turn them off during breaks, or when a specific actor is not going to act for an hour or so, I very rarely have to replace the batteries on set.

I never discharge them all the way.

A very knowledgeable person, one who had tested the life of common brands of alkaline batteries stated that the Duracell Pro brand had the lowest capacity of any brand. This was reported as a post on DVinfo.net.

Someone else posted that all of his Energizers still work. The only ones that didn’t were the ones he lost.

I noticed on the Energizer site that it says not to recharge a cold battery. It will permanently lose capacity.

Do what works for you. Energizer rechargeables work well for me.

Do what works for you.

hmmm, possibly the quote of the century. ;)

I have been using 2600 mAh Tenergy AA and 250 mAh 9V batteries in my wireless (Zaxcom and Lectros) for several months now and haven't had any issues. I also use a fast charger on both and like Dan points out, you really have to charge them the day/night before to get full use out of NiMH batteries.

We burn through a ton of batteries during a shoot where standard Alkalines are used (I've worked with people who refuse to use rechargeable batteries), and I just can't see doing that myself, so when I get the chance, I use rechargeables.

Wayne

the Duracell Pro brand had the lowest capacity of any brandWell go figure that's what I'm using...

I'm going to get a set of the 2700mAh Energizers tonight and give them a whirl and see how they work for me.

I was surprised at the Sennheiser battery pack - they're rated 1500mAh which one would think isn't nearly as long lasting as the higher capacity batteries. But then again, I know nothing about this stuff.

Given this, why would I want to risk using rechargeable batteries on a shoot? And to tell the truth, I am not sure how much I am "saving" using rechargeables. I can get Duracell Pro alkaline's for .40 a pop. When they won't power my G2, they will power my remotes. We use the rechargables in camera flashes for the short recycle time- but a 10-pack is $25 and they generally last about a year before recycle times diminish and I start all over again.
Anyway, I would not trust rechargables in any of my audio gear.
Mike

for starters, yes there is money to be saved with rechargables, another is being able to charge them and have a fresh set instead of running to the 7-11 at 10pm for a last minute job and paying crazy money... and last, and perhaps the most important is that batteries are some of the nastiest toxic waste we generate on a day to day basis composed of lead, mercury, and such. not good landfill material.

rechargables have worked fine for me, I run my audio bag off of a pair of 12V 5A paks I had custom made. they run 8-10 hrs with both wireless receivers on, more without, and recharge in a 1/2hr or so. if I powered my rig with 6 9V batteries, even cheap ones at $1.50 each would be $9/day. if you pay more like $3ea, thats $18/day. I did one 10 day straight shoot, that was $90-$180 I didn't spend, and 60 9V batteries that didn't go into the landfill. I'd call that significant.

AA's come in a wide variety of quality. another option with the sennheiser paks might be to go to an external battery pak with one extra cell.

I've read that some nicads with higher internal resistance can alter the power supply current flow and cause transmitters to act just like you have experianced. I'd try a different set for starters, then call Senn about a warranty exchange because they should work.

i switched from alkaline to rechargeables for my G2s when I discovered sanyo's Eneloop batteries. They have less capacity (although more than i've ever needed for a full day's shoot) but they dont discharge nearly as fast when sitting idle. Where my other rechargeables will drop to like 20% power after a few weeks, the eneloops hold well over 95%... and supposedly will hold up to 90% after a full year.

I gave away all my regular rechargables, bought 40 eneloops, a 10 bay individual cell smart charger and i'm a happy clam. After a shoot I charge up the batteries and put them back in the sound case, confident that they'll be good when I need them. (like alkalines). If i have a critical shoot and have been idle for a month I might stick them back on the charger... but i've had such good luck w/ them that I generally dont.

As to the "fuzzy" sound... I'll have to listen closely and see if i can actually hear that. I dont have the greatest ears, but I would think i'd notice something like that.

Actually, i have two sets of G2s. maybe I'll put one on alkalines and one on eneloop and record a test for you golden eared freaks out there.

cheers!
-a

Here's the rub: I can put new, 2750 mah batteries into my R4 and if it powers up, it won't be for long. I can put the same batteries into a Canon 580 flash, discharge at full power and my recycle time is approx. 5 seconds and the batteries will go all day. If I put alkaline batteries in the R4 I am good to go for a few hours. I can repeat the above any day of the week with any rechargeable. Moral of the story: there is most definitely a difference in how some gear responds to or how the rechargeable delivers power to the gear. Given this, why would I want to risk using rechargeable batteries on a shoot? And to tell the truth, I am not sure how much I am "saving" using rechargeables. I can get Duracell Pro alkaline's for .40 a pop. When they won't power my G2, they will power my remotes. We use the rechargables in camera flashes for the short recycle time- but a 10-pack is $25 and they generally last about a year before recycle times diminish and I start all over again.

Anyway, I would not trust rechargables in any of my audio gear.

Mike

If by R4 you mean Edirol R4 then I have one. Runs fine off NiMH batteries. There is a setting in the menu from memory to tell the unit you're using NiMH batteries. If you fail to set that then yes the unit will very quickly do its power down thing thinking your alkaline batteries are almost flat. The unit has to work that way as a sudden loss of power will almost certainly mean the loss of a recording.

Dear Bob,

That is great information!

I am sure that information will help more than one individual.

So I went around and around with this when I bought a sennheiser G2 setup 2 years ago. Couldn't figure out where the "fuzziness" was coming from. Finally a friend told me to try the energizer lithium disposables (blue package). Worked perfectly. The trouble with the rechargables was when they started to go, you had no warning. Just suddenly fuzziness 30 minutes into the shoot.

I know it's $9 a shoot, but I can't afford to have the audio go bad, for just $9.

I purchased eight 2500 mAh Ni-MH batteries online last year. The brand is Merkury. They've always worked well, but I've never really tested them. I charged them, four at a time, in a Panasonic 5-hour Ni-MH charger. each set of four kept my wireless running for over nine hours. (The tested ended because I took my wife out to dinner.)

Fully charged, the meter on both the transmitter and receiver show a full charge and it remained full for an hour. After that it went to two bars (out of three) and remained there for eight hours until I finally left the office.

Today they were dead. ;-)

So, they lasted between nine and twenty-four hours. I'm guessing closer to nine.

These are them:
http://www.thomas-distributing.com/merkury-aa-rechargeable-batteries.php

I just found this site - they done some cool comparisons.

http://www.rechargeable-battery-review.com/consumer-batteries/aa-battery-tests/aa-nimh-battery-performance.html

Sorting by "Tested Energy," looks like Merkury scores pretty low. The top of the list are Powerex 2700, Ansmann 2700, Ansmann 2800, and Sanyo 2700. And Duracell rates higher than Energizer! Hmmm.

And the results...

http://www.rechargeable-battery-review.com/rbr-editors-choice/2006-editors-choice/2006-top--aa-rechargeable-battery.html

Perhaps my next rechargeable purchase?

http://thomasdistributing.com/shop/-maha-mhc204w-white-world-charger-kit-combo-brincludes-four-2700mah-aa-maha-batteriesbr1-free-maha-deluxe-travel-bag-br1-free-8-cell-and-1-four-cell-battery-holder-p-570.html?SP_id=52&osCsid=o4atakfsu5q0v0ccjl6g98t682

I've been using Maha PowerEx 2700mAh NiMH AA's in the Edirol R4-Pro, this lasts 4-5 hours before swapping batteries. In the G2's I use them as well and they work just fine, no difference in audio quality compared to alkalines. Forget average life in the G2's, think I swap em once a day. Also, I always use a one hour charger. my $0.02
cheers

I have been using the Rayovac Hybrids. Runs my G2s at least 10 hours without powering down. Even holds the charge when unused 70 -80% or more than normal NiMHs. I was going to buy the DC power adapter for the receivers and power externally, but with that kind of battery economy it wasn't worth the expense or trouble.

Rechargeable batteries loose power the more you use them. The more you use them the less they hold a charge. Allot of electronics manufacturers specify that you not use rechargeable batteries and run only fresh alkaline batteries.

I have been using the Rayovac Hybrids. Runs my G2s at least 10 hours without powering down. Even holds the charge when unused 70 -80% or more than normal NiMHs. I was going to buy the DC power adapter for the receivers and power externally, but with that kind of battery economy it wasn't worth the expense or trouble. Unlike my Lectro receivers that eat 9Vs two at a time, which makes external power almost a necessity.

King of the Hill: Energizer AA Lithiums.

Pro: Last about 3 times longer than anything else, 40% lighter in weight, 10 year shelf life.
Con: cost a lot

I've been using the powerex 2700's on my G-2's. They run all day and barely dent the battery meter.

Rechargeable batteries loose power the more you use them. The more you use them the less they hold a charge. Allot of electronics manufacturers specify that you not use rechargeable batteries and run only fresh alkaline batteries.

Sennheiser sell a set of NiMH batteries for use in the G2 kits. Needless to say they are expensive, no different to other NiMH batteries and you need their charger to charge them as they're in a plastic housing.

Keep in mind that the high capacity NiMH cells have a high self discharge rate of around 1% per day. If this is an issue Sanyo and a few others make 2100mAH cells designed for remote controls with a very low self discharge.

We have found that the hand held Senny wireless mics will not work with NiMH batteries.

Well if you're investing in NiMH batteries, you should also be investing in a charger that has options. Look up the Maha / Powerex MH-C9000. It's the best way to keep your batteries healthy.

I had Energizer 2500NiMH batteries that would only work for about 2 hours in an SMa transmitter. I did a refresh and analyze, and now I get almost 4 hours.

We have found that the hand held Senny wireless mics will not work with NiMH batteries.

I have not tried the Rayovacs in the Senny H/H. I do get about the same economy in the butt-plug configuration with a dynamic mic.

Just a word from a Network and Major Studio viewpoint. You will NEVER see rechargables being used on a production. We used to use Duracell Procells until lately purchasing must have gotten a deal for Energizer Industrial batteries. Peoples jobs are too important to rely on rechargables....

I'll back up what George (and others) said. We have 4 Sens HH, 2 Sens Lav, 2 Shure HH, and sometimes Lectros (rented) we use on stage for our audio company. We also do system installs. We NEVER use recharg-o's and recommend to all clients we install systems for to follow the same advice.

BTW: Mic problems from recharg-o's falls into the top ten reasons for service calls on systems! (Fortunately it's an easy fix).

Just my 2 cents...

The only batteries you should use in a G2 are standard alkaline AA size (eg: Duracell or ProCell) or the Sennheiser BA 2015 rechargeable pack.

You should *not* use standard AA rechargeables.

The BA 2015 has three contact points and "talks" to the transmitter or receiver.

BTW: Mic problems from recharg-o's falls into the top ten reasons for service calls on systems! (Fortunately it's an easy fix).


How could they damage my gear, and what kind of easy fix ?

thnks

How could they damage my gear, and what kind of easy fix ?

thnks

I don't think he meant damage.. just meant they are the cause of issues that stem from the use of rechargeables.

All rechargable batteries are not created equal. They all have different characteristics. Here's a general description:

1) Nicad- cheap, but can build up a "memory" over time. The put out a lot of power.
2) NiMHs - better than Nicad. They also put out a lot of power for high current applications.
3) Lithium - lasts longer than NiMHs, but they don't put out as much power.

For example. If you bought two identical radio controlled cars and put NiMHs batteries in one and Lithium in the other. The NiMHs car would run much faster but run dead quicker. The Lithium would run slower, but last longer. It's like the NiMHs has a larger "pipe" to put out power than the Lithium.

I don't have any idea how much current draw the G2 uses, but I'm guessing that the better choice in this case would be the Lithium rechargeable batteries.

I use a Letus 35mm spinning ground-glass adaptor. If I put Lithium batteries in it, it runs a long time, but sometimes, when I press the power button, the ground-glass won't start spinning. I have to "help it out a bit" (don't ask). But when I run standard alkaline or NiMH batteries, it always starts right up, but it doesn't last as long.

Does that make sense? It probably doesn't help much, but I thought it would be good information to add to this discussion. :)

I don't have any idea how much current draw the G2 uses, but I'm guessing that the better choice in this case would be the Lithium rechargeable batteries.

No - the only choice is the BA 2015 rechargeable pack which was designed specifically for the unit and "talks" to it via the extra contact.

Hopefully Sennheiser isn't still using nicads for their battery packs. If so, you'd be better off with rechargeable lithium's (although they wouldn't "talk" to the unit)

Hopefully Sennheiser isn't still using nicads for their battery packs.

They are NiMh as far as I'm aware and have been for years.