just comtemplating using the ni-mh rechargeable AA's
Im finding myself with a load of spare nearly used batteries
and no way to use them up.
Recommend or not?

Hi. If you look at the top of this forum there is a post "Frequently Asked Questions" and within it are some threads about rechargeables. I'll summarize since I've read them all in my own quest to answer the very same question:

People either love 'em or hate 'em! NiCad rechargeables are not reccommended by any manufacturer's site that I looked on; if you are going to use rechargeables than NiMH is the way to go. The biggest complaints about rechargeables boil down to:

1. They can lose charge and die without warning which is bad when you are on a project. I just bought a drill with NiMH and the manual clearly states "the battery will die unepxectedly and completely when the charge is exhausted."

2. There may be a voltage difference. Most alkalines AAs are 1.5 volts; rechargeables are 1.3 or 1.4, that little bit might make a difference.

3. It's easy to mix up the charged batteries with the depleted ones. You'll need a system.

Having said all that, both Sound Devices and Sennheiser responded to my email and said that NiMH were acceptable in their products. Senn was specifically answering my question about the G2s.

People who use their gear professionally everyday often get a stand-alone dedicated battery system to run all their audio gear but that's head and shoulders more costly than over the counter batteries.

For the time being I'm sticking with alkalines. As much as I'd like to be "greener" I'd hate for the system to die in the middle of a take.

Bob

Thankyou Bob,
that was very helpful.
I think you have made my mind up for me too.
Just while we are on the subject.
Is anybody here actually doing live event stuff
with recharegables in their g2 kit?

I find that the Energizer 2500mah AA's work great in the Sennheiser G2's, when using the proper techniques.

By "proper techniques", I mean

1. Charging them the night before the shoot.

2. Measuring the voltage with a good digital voltmeter to ensure that they are properly charged. I sort them by voltage and use the higher voltage ones and recharge the lower ones.

3. Turning the G2's off when not in use.

4. Switching out the batteries when appropriate. If I have an all day shoot, I usually install freshly charged batteries at lunch.

5. I also monitor the battery, via the readouts on the G2's. If they get low, I switch them out.

With these techniques, I have never had a problem.

I also use these batteries in my Sound Devices 302 and they work very well.

I use NiMH (9.2 and 9.6v in my Lectro units, and AA in my Zaxcom units), batteries because I really hate tossing used batteries away. In the long run you can buy a nice charger and lots of batteries for less money than constantly buying regular batteries. Both Lectrosonics and Zaxcom also recommend using NiMH rechargeables. In fact, it is the preferred way of using the Zaxcom units because they are so power hungry... by preferred, I mean it is recommended to use them in the user manual.

Wayne

I use rechargeable batteries in everything, including SD302 mixer, wireless units, cameras, etc.

A good brand is Powerex. I have both 2500 and the newer 2700 AA:
http://www.mahaenergy.com/store/Index.asp

Powerex also makes 9v and 9.6v batteries.

Get a charger with independent circuits that charges each battery separately from the others.. The Maha chargers are very good. I use the ones that accept 110-240v.

Thomas Distributing is a company that I have bought a lot of batteries from and carries the good products. (This is not a sponsor here, but it's kind of a specialized product line.)

I agree with the post above about taking care in using the rechargables. But I have never had a problem.

thanks guys,
is it ok to charge those ni-mh anytime or do they have to
be fully depleted like the older type?

You can charge a NiMH at any time.

I feel that it is better to not fully discharge them, but that is my personal preference. I do not treat them like NiCd's, which should be fully discharged before recharging.

Whenever possible, when they get low, I just recharge them.

It is important to recharge them just prior to any important gig. By this, I mean the day before.

The Maha charger I have lets you leave the batteries on it all the time.

The good chargers also give you two charging options: slow and fast.

The slow option gives you a bit fuller charge and less "wear" on the battery. The faster charge is faster (and a bit hotter).

Some of the Powerex/Maha kits comes with a bag to carry everything in.

Some chargers include a 12v car adapter as well as the as adapter.

When I bought batteries I also got plastic cases that carry four or eight batteries (AA). I charge the batteries then put them in the case and put a small piece of tape on the case, using this to tell me these are fresh batteries. I put the used batteries in a case with no tape and then into a separate colored cloth bag.

I also have some alkaline batteries "just in case" and for when I might have to use them for an unusually long time.

It's not difficult to check your equipment to see how long the batteries will last in any particular device. Just put the rechargables in, start the device running under a working load, and see how long it goes.

You can get a set of four batteries and a four battery charger, for example AA, and try them out. Then buy more if you like them. Otherwise, there's always something to use the four you bought in. I know one guy who has a 4 battery charger and 8 batteries. His little Canon takes 4 batteries. He always has 4 batteries in the camera and 4 in the charger.

ok, im going to go ahead and get myself the best charger i can
with 8x 2700 AA

My main reason is the environment but it wil also
make financial sense in the long term.

Bob, I'll let you know in a few weeks how i get on.

Just for reference:

The Engergizer charger (7 1/2 hour) which charges 4 batteries simultaneously plus 8 AA's and 4 AAA's costs under $30.00.

I have 20 Sanyo 2500 mA NiMH AA rechargeables and two 4-battery chargers. They're cheap and reliable and I use them in both my G2 sets and my Sound Devices 302. The only downside is that they output 1.2V, which messes up the battery remaining readout (a fully charged batter shows 2/3 bars in G2 components). Aside from that, they've been great.

I have been very pleased with the Energizer's in the Sound Devices 302.

On a recent four-day shoot in December, with each day lasting over 9 hours, the batteries held up well. I was using 48V Phantom Power, on only one channel, to power a Schoeps 641.

To be ready for this shoot, I charged the batteries the night before. If I remember correctly, each battery read about 1.4 volts just before use. When the charge-cycle ends (or when the batteries get hot), I remove the batteries from the charger, if possible.)

I left the 302 on between scenes. If I expected the setup for the next scene to last more than 10 minutes I turned off the 302.

I used freshly charged batteries at the start of day 1, day 2, and day 3. At the end of the day, the battery level LEDs on the 302 still read near the top. I recharged the batteries each night.

As a test, I left the same batteries from day 3 in for the start of day 4. We only worked 5 hours on the last day and the battery level LEDs still read near the top.

To be clear, the battery level gauge read the same at the beginning of the day as at the end of the day.

I have posted my postive experiences with the Energizer rechargeables.

I realized that I did not report its negative aspects.

With the low cost Engerizer chargers that I have, you have to charge the batteries in pairs. It will not charge just one battery, so you can charge 2 or 4 AA's, or 2 or 4 AAA's or 2 AA's plus 2 AAA's, but not one three batteries (In this case 2 will charge, the third will not).

There is only one LED to indicate that the charger is in charging. You can not tell if one pair is charging and the other pair is not, due to a battery seating problem. So I just ensure that the batteries are properly seated.

The charging routine is fairly simplistic, it is a timed slow charge. This takes approximately 7 1/2 hours. At times the batteries will get warm (or hot) since the charger continues after the batteries are full.

I remove the batteries if they get hot, then measure their voltage to ensure that they are fully charaged. Then I again measure the voltage just before I use them.

Note: There are other, much more sophisticated Energizer chargers, such as the more expensive 15 minute charger. This one detects when the batteries are full and charges them with a much higher current.

I would love to know whether this fast charge is harmful to the life of the battery.

Recently Energizer introduced new model chargers which I have not yet used.

On Jacks MAHA recommendation
I noticed this charger in Maplin (electronics store).
Im thinking of going in tommorow to pick one up with
some good powerex batteries.
What do ye think?
We are looking at about €100/ $120
I know its a lot to pay compared to
some other ones but when I think about it
I feel I cant afford to be let down by these, ever.
I think it should do the trick.

Seems there are several factors in keeping a nimh battery healthy alright.
http://www.maplin.co.uk/Module.aspx?ModuleNo=217900&criteria=maha%20charger&doy=13m1

On Jacks MAHA recommendation
I noticed this charger in Maplin (electronics store).
Im thinking of going in tommorow to pick one up with
some good powerex batteries.
What do ye think?


This is an awesome charger. It is the one I bought and use on-location all the time. Each battery has it's own charger, so you can put in any combination of batteries and conditions. I highly recommend this charger. It does both fast and slow charging too, which is very nice. It there is any downside to it, it is that it doesn't do 9v batteries, but if you need a 9v charger, there are plenty of those around.

Wayne

Hi
Maplins do their own brand re-chargeables and they are very good. I have the 2400 and 2600 and they are far far better than the Uniross 2700 that cost nearly twice as much.

So I would advise going for their own brand AA's.

In fact the Uniross are bad. They loose their charge quickly, even over night I find they are far less charged than the Maplins. That means they take far longer to charge up as well as they retain very little.... glad I only bought 4 of them.

I have the 35 minute charger that Maplins have discontinued un-fortunately as it is also very good though more expensive.

Here is an excellent overview of some of the best rechargeable batteries and charger options:
http://www.steves-digicams.com/nimh_batteries.html

If you're buying new NiMH batteries, be sure to check out the 'hybrid' versions. The main advantage with the hybrids is a significantly reduced self-discharge rate. I've just started using some Sanyo Eneloop hybrids and it's really nice how they retain their charge. I don't have to charge them up just prior to using them. Sanyo claims that their hybrids retain 85% of their charge after a year.

-Dan