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Rechargeable vs alkaline battery runtime?


Rasmus Wedin

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Hi

I was planning to invest in some rechargeable batteries, probably the Powerex 2700 since people seem pretty happy with them. Just wondering if someone could give me some pointers to how long these kind of batteries usually last in a tx? Basicly how long runtime before I need to swap batteries? I know there are no certenties, but generly speaking.

I'm using Varta-alkalines right now and I get 9-10 hours on those. Will 2700 NiHm last longer or shorter than those, or other high end AAs? Anyone got some experience to share?

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as my close personal friend Oleg has pointed out: Ohm's law plays an important part in determining battery life, along with other factors like the cell's and chargers used, and how they are used.  most of the cells come from only a couple different factories.

this has been thoroughly discussed, so try some searching on jwsound.net.

and of course: YMMV

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regular alkaline is rated  average 2800ma for 1.5 v =4.2watt

the rechargeables are 1.2 ( average) for 2700= 3.2 w

but

alkalies falling down in voltage under load , so actually you can get these 4 w only if your device is using small current , while the ni mh stay same voltage under load and you can use all the capacity .

for example the alkaline inside lectro transmitter will hold half an hour as the voltage  is coming very fast under the minimum of what the dc to dc converter need  while the nickel metal will last 4 hours .

what exactly you intend to power as this is the main issue to you answer ?

Thanks for the answers. They will used to power G3s and Wisycom tx's. My Varta Alkaline batteries last around 9-10 hour at the most, but I usually change them after 8 hours to stay safe.

I might be thinking to try and power my 302 mixer with them later on. Would that be to my dissadvantage if it drains more power?

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" Would that be to my dissadvantage if it drains more power? "

No, it would be to your advantage, as the rechargeable batteries are useful over and over again! Thus you will be buying and using even less alkaline batteries.

What I ment was, would a 302 mixer drain rechargeble batteries faster than alkalines.

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I might be thinking to try and power my 302 mixer with them later on. Would that be to my dissadvantage if it drains more power?

Just for fun I tried some Energizer and Duracell rechargables in my 302s and most of them didn't fit into the battery tube.  I guess that would be a disadvantage?

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I use rechargeable AA in everything, and they consistently last longer than alkaline batteries.  I have not had fitting issues with my 302.

The only size issue I have encountered are in the new Ambient Lock-it boxes.  For these, I use the Eneloop batteries.  They last a whole day and are the same size as Alkaline batteries.

Robert

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I have two 302 mixers.  I just tried both of them and ... the Powerex batteries fit fine in one of my 302s but not in the other.  Darn.  Guess which mixer was in my bag and which was the extra?

I tried the Energizers and Duracells in both ... some fit and some don't.  So, I guess I'm not nuts? 

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I have two 302 mixers.  I just tried both of them and ... the Powerex batteries fit fine in one of my 302s but not in the other.  Darn.  Guess which mixer was in my bag and which was the extra?

I tried the Energizers and Duracells in both ... some fit and some don't.  So, I guess I'm not nuts?

If you can find an internal micrometer you could measure the battery tube and see the differences. Of course you could always grind out the diameter of the smaller tube with a fine emery cloth glued on the proper size drill bit chucked up in an electric drill. As an FYI nominal diameters for alkaline batterys are 14mm.

Eric

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Thanks for the answers. They will used to power G3s and Wisycom tx's. My Varta Alkaline batteries last around 9-10 hour at the most, but I usually change them after 8 hours to stay safe.

I might be thinking to try and power my 302 mixer with them later on. Would that be to my dissadvantage if it drains more power?

I use G2s as a camera hop and boom op talkback. I'm using a mix of AA brands to test them all out. I had great results with Powerex and the Ansmann AA NiMH 2850 batteries. We would often get a full 12 hour day out of them in the G2s. They always lasted the full day in my boom op's SD MM1. We did a few super long days (like 17 hours) and would swap it out then.

I have not tried them in my 302 mixer because I use a NP-1 powered BDS for the mixer and my Lectro receivers, but in other threads I have read that people had good results with them.

on a side note... On the film I just wrapped, we ONLY used disposable batteries in a UH400A (which does not play nice with iPowers). My Lectro, Zaxcom and Sennheiser transmitters, Denecke slate, sync box, etc were all running off rechargeables with great results.

(The Zaxcom and Lectro receivers were powered off a cart or bag battery system, not AA or 9volts)

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I use G2s as a camera hop and boom op talkback. I'm using a mix of AA brands to test them all out. I had great results with Powerex and the Ansmann AA NiMH 2850 batteries. We would often get a full 12 hour day out of them in the G2s. They always lasted the full day in my boom op's SD MM1. We did a few super long days (like 17 hours) and would swap it out then.

12 hours sounds great. We usually do 9-10 hour days, and it would be great to not have to change batteries. Thanks!

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on a side note... On the film I just wrapped, we ONLY used disposable batteries in a UH400A (which does not play nice with iPowers).

This was discussed On Ramps last year it only happens with a very select  few UH400A here is what Larry had to say about it:

We can modify the UH400's for a soft startup so the iPower protection circuitry doesn't trip. The fix is not free but it does completely  solve the problem. Most units made since June 2008 will already have  the different power supply chip and the associated parts for the soft  startup. Keep in mind, this wasn't strictly our problem. It became our  problem because our customers were having problems.  We did have an iPower battery several days ago that still had turn on  problems but it was sensitive to RF. A tiny capacitor (100pF) between  the terminals was enough to cure this iPower's startup problems.  Serial numbers are not great indicators since we have so many  different frequencies. The serial numbers are assigned early in the  build cycle but the units can take very different times before they  are finished. The only way to tell would be to call in the serial  number and have its date of manufacture confirmed. The cost is $100  total to replace the power supply chip with a  soft start enabled part plus the timing caps. While the unit is here  we will also do any mandatory updates (always free) and fully retest  the unit. Sometimes we don't even have left over pieces.  Best Regards,  Larry Fisher  Lectrosonics

So if your having an issue Lectro can let you know if your unit is one of the ones that needs a new chip.

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This was discussed On Ramps last year it only happens with a very select  few UH400A here is what Larry had to say about it:

-snip-

So if your having an issue Lectro can let you know if your unit is one of the ones that needs a new chip.

yeah, I have one of those UH400s. For some reason I thought it was more common than that post makes it sound... maybe because the one I own is susceptible? :)

The thing is that I pretty much only use my UH400 for my CUB01.

My UH400 is also one of those blocks we don't really use anymore, so that's a bigger concern. I use it so infrequently that I have not gotten around to replacing it yet.

When I have time, I need to send in my CUB01 to get the RF fix, and the TA5 breakaway I didn't get from the start. When I do that, I will be using the UH400 even less. On this most recent film I might have gone through half a dozen 9volt procells in the UH400 for some of the car rigs where I could not hard wire it to my Fusion.

(sorry to go off topic)

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If you can find an internal micrometer you could measure the battery tube and see the differences. Of course you could always grind out the diameter of the smaller tube with a fine emery cloth glued on the proper size drill bit chucked up in an electric drill. As an FYI nominal diameters for alkaline batterys are 14mm.

Eric

IIRC the problem is that some rechargeable batteries may swell a little bit when under heavy use. I've never had it happen to mine, but I thought that was a possibility. That was why I used lithiums in my MM1 for so long. I had no issues with my rechargeable batteries, though I did have a backup external battery ready just in case.

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  • 1 year later...

NiMh rechargeable batteries have a better current sourcing capability ... means usually it last longer on portable device.

- We tested (2011) our Tx with many Alkaline batteries and the best performing brand was ENERGIZER, more 10h (50mW) and 14 hours (10mW) with our MTP30 tranmitter.

- With good NiMh rechargeable batteries u can get at least a 5/10% better than alkaline, but of course u need to take in consideration the wearing out of capacity during life.

/mAX

Wisycom

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