MartinTheMixer

5 minutes ago, Johnny Karlsson said:

I'll add one more last thing: I do absolutely NOT recommend these for use in a Lectro Tx.

 

I rolled on the last test and just spot checked it. There were loud pops intermittently towards the end of the file. Pop, then dead silence. Then it would come back on again. Then POP again. On and off a few times, so that would mean usable run-time is likely about 4h. After that it would be scary. I'm guessing this has to do with what Larry mentioned (the switching power supplies trying to figure out what to do with each other once the voltage starts dropping).

 

So meh - sticking to my eneloops.

I believe what your referring to is the cutoff protection in the cell itself.  This can be tested. 

3 hours ago, RadoStefanov said:

And besides: Not knowing your battery is about to die immediately disqualifies this battery.

When I use the micro USB rechargeables, I think mine are a different brand, I just change the erx batteries every 15 hours. 

57 minutes ago, RadoStefanov said:

So it is not the battery but the transmitter design.

And in this scenario NIMH will have a better run time considering the higher mAh and the way lectrosonics draws less when voltage is lower.

You can also decrease your RF power to extend your run time. Still nothing to do with the battery.

The way it "draws less when voltage is lower", less what? 

47 minutes ago, Johnny Karlsson said:

You have that backwards. The transmitter draws more current at a lower voltage. And for real runtimes, there was no significant difference in the tests I did.

 

Feel free to believe me or not, or run your own tests. I'm done with this topic. I just wanted to share my findings for anyone who cares. Not here to "win" an argument. Cheers !

I didn't know there was an argument. That shows how little I know. 

5 minutes ago, RadoStefanov said:

To calculate the run time we are comparing the same devices at the same draw right?

And different cells with different internal resistance figures and probably different temperatures of the device and the cells and maybe different amounts of grunge on the rechargeable cells? And probably not, I'm just speculating here, a very smart charger that can see what's happening in the cells and report that info to the user. 

4 minutes ago, Johnny Karlsson said:

Right, but...

The theory I wanted explore was that the transmitter draws more current when the voltage is lower, and therefore would potentially drain the battery quicker.

 

This Lithium AA:

 

3300mWh @ 1.5V = 2200mAh

 

And NiMh:

 

2450mAh @ 1.2V = 2940mWh

 

2550mAh  @ 1.2V = 3060mWh

 

2700mAh @ 1.2V = 3240mWh

 

Of course, one thing that throws the formula off is, the NiMh doesn’t start at 1.2V fresh off the charger. It can be as high as 1.47V, then drops down to around 1.35V over the first 15 min or so. Then gradually drops further. So using the above calculation formulas does not give you the accurate comparison. That’s why running the tests in real life seemed to make more sense. And again the tests I did shows that the practical run-time is about equal.

 

 

A couple of things to consider. I don’t think any of us are running Energizer lithiums until their dead, so, users vary, but maybe 20 percent of the capacity of an energizer lithium is unusable. On the micro USB rechargeable, you can change as often as you like and you're never "throwing away" capacity like we do with the Energizer lithiums. And, the current doesn't go up on the rechargeable lithiums because they start at about 1.5 volts and once fully discharged, they are still about 1.5 volts.  Thank you. 

2 hours ago, LarryF said:

The li-ion rechargeable battery has to have a sensing circuit to turn it on when there is a load, otherwise it would stay on all the time and run down in a day or so from the voltage converter residual drain. My guess is that in the two battery setup in the SMQV, the higher voltage li-ion battery is turned "on" while the other battery sees more than its full voltage at its output and thinks it is looking at an open circuit, i.e., not in a device. It stays off. At some point the first battery begins to die and the second battery sees less voltage than open circuit and tries to turn on. If it starts to power the SMQV, then the first battery sees less of a load on its internal cell and it tries to turn back on. My guess is that the SMQV doesn't know what to do with rising and falling voltages and shuts down. Having three switching power supplies all sensing the input voltage (two outputing in the two batteries and one inputing in the SMQV) , I'd be very suprised if the various units didn't go into oscillation. It would require a scope hooked up to the units to decipher the problem.
By the way, the Lectro transmitters will operate at full power down to 0.9 Volts, so as to get every bit of power out of an AA battery.
Best Regards,

Larry Fisher

Larry, Good stuff to know, thanks for the answer. 

.9 volts, wow, what is the amperage at that point? 

19 minutes ago, LarryF said:

Parallel.

Larry (Odd Designer) Fisher

Larry, haha,  I looked it up, I see the battery eliminater, now I see what you were doing. What is your theory on what happened in the referenced case? Only one battery reported to have been utilized. I still stand by my position that this scheme is different than what is usual or expected. Is there any other transmitter manufacturer that uses this scheme? Thank you, Martin

5 hours ago, Johnny Karlsson said:

Like I said, it does. See the above tests. It’s a well known fact. Not sure why you would have a hard time believing that. 

Why would I have a hard time believing that? Because that is an odd design. 

47 minutes ago, Johnny Karlsson said:

I believe they are in parallel. Otherwise it would double the voltage, right? And since you can run an SMQV with a single battery....

This would be easy to identify, try checking if it will run with a cell in either of the 2 positions, 1 cell at a time, if it does run, then yes, it is in parallel, which I have a hard time believing. 

Hi Johnny, are you saying that somehow, the 2 batteries were wired in series, and somehow the unit managed to not use the one cell, that was in series? Hey SMQV people weigh in here, are the 2 cells in parallel? And not series? 

Thank you. 

2 minutes ago, Johnny Karlsson said:

I don't know of any professional gear that needs exactly 1.5 V and stops working at 1.49 V. If this was the case, no existing regular AA alkaline, or Lithium batteries would work more than 5 minutes.

These lithium AA from iPower run at an internal higher voltage (IIRC 3.6V?) with a regulator that keeps the battery output at 1.5V. FWIW - their run time is about equal to, or less than Eneloop Pro, or Ikea Ladda 2450.

 

The marketing mumbo Rado is talking about is likely the fact that they use mWh rather than mAh to make it look at first glance like these have much higher capacity, but the reality is that 3610mWh equals about 2406 mAh at 1.5V. Of course, you could argue that the transmitter will pull less current at 1.5V vs 1.2V, but I'm not sure if that matters much in this situation.

 

Personally, I stick to Eneloop Pro, or Ikea Ladda 2450. I know they will run single battery Lectro Tx for 4+ hours, and double battery Tx for 8.5 hours and both have proven to be consistently reliable. If the situation is such that I need to leave the transmitter on all day without any chance to swap batteries, then I go for Energizer Ultimate.

Thank you for your input, as I was simply addressing someone who had indicated that they were not happy with the voltage dropping to 1.2 volts. I am happy to see you agreeing with me about these batteries maintaining a higher voltage. The user of the device who did not care about the voltage dropping to 1.2 on the older style batteries, Nimh, Nicad, etc, would not have this issue on the newer cells. And of course when the voltage drops, the amperage goes up, absent a circuit that subsequently lowers the wattage as the voltage of the cell drops, then heat also goes up. That is why I don't use a main battery system of 12 volts on Nova, because of higher amperage. The other reason being the minimum  voltage level of the Nova is reached before the discharge level of the battery pack is reached, thereby leaving unusable power in the battery pack. As far as "Mumbai" , I was simply doing math based on the science.

1 minute ago, RadoStefanov said:

Not sure what your answer is. 
you are buying ipowers sales men Mumbai jumbo. 
How long a battery stays over 15V “thanks for clarifying” should have no affect on a properly designed equipment using an officially standardized battery. Unless the manufacturer don’t know how to make a battery power device. 

I didn't mention anything about equipment design. I don't know the "Mumbai jumbo" you refer to and I'm not sure you understand how these cells function. Think of it this way, if there was a piece of equipment, let's call it the Throwtrap 5000, and this device ran on 1.5 volts minimum voltage, at 1.49 volts there is no longer enough voltage to power the 5000. This is what we are discussing here. With that understanding, how long does the cell in question maintain 1.5 volts? 

3 minutes ago, RadoStefanov said:

Huh?

what?

what are you trying to say?

 

Not sure what your question is. 

1 minute ago, RadoStefanov said:

And as I said  even their own specs are exactly as I stated. 
Again “but maybe a little clearer”:

how do you get to the conclusion that this battery will run longer than energizer lithium?

I addressed someone who didn't seem to care for the voltage running at 1.2 volts. I guess the way for you to think about this equation: If you were to measure these 2 different types of cells at 1.5 volts or higher, which cell would provide a longer run time at or above 1.5 volts? There is the answer. 

38 minutes ago, RadoStefanov said:

not even close. Where do you get this? Those are maybe a little bit better than 2500mAh eneloops and 2700mAh powerexs “by their data”. But I don’t trust manufacturers claims very often. 

I use eneloop Pro 90%
they are a money maker and  keep zaxcom transmitters a lot cooler. 
Also I 100% prefer the expectability  and consultancy of NIMH compared to the the opposite in lithiums. 

 You asked "where do I get this?" and then talk about one being "better". I didn't say one was better or worse because of this, I made the statement that the cells at discussion here would be at 1.5 volts longer than Energizer lithium, and since a depleted Energizer Lithium has 1.5 volts for less time than the battery than the ones in this discussion, that is where I "get this". 

21 minutes ago, Ontariosound said:

I gave up on rechargeable AA's many years ago.  In my Lectro SM's they would level out at 1.2 volts and always have me

concerned with that number when viewing on the 411A's.  And they are heavy.  Similar issue in my TS3 EL slates, the 

apparent cruising altitude voltage of 1.2 was tricky. And they seemed to swell up in the tight sled and tunnel.

I did like them in my Zaxcom RX 200's, long life.  But heavy as a tank and that quick jump from 6 volts to 5ish was irritating ( 4 AA's).

So I just use Energizer Ultimate Lithiums.   When the voltage starts to drop and drop, time to replace.  They have gone

up in price but the light weight and predictability is comforting.  Granted, Documentary is my main focus.  If I stuck with scripted Union shows a charging station and a Boom Op and Utility would make it more environmentally friendly.

 

Well, if it helps, the batteries we are discussing here have 1.5 volts for a longer period of time than Energizer lithium. I understand your hesitancy with rechargeable AA batteries from 20 years ago, but things change. We didn't have electric cars 20 years ago and needlessly throwing batteries away is not a great thing.

Sincerely,  Martin

On 7/2/2016 at 2:59 PM, MartinTheMixer said:

Mark, That's what I was beginining to think, about the big surge for the flash charge. I was sure those batteries would be weird. Just not for the reasons I thought,  not so far anyway.

22 minutes ago, VASI said:

Going to bring back from death this topic (lol)

 

Does someone has experience how it's working the new model?

 

https://www.ipowerus.com/products/aa-3610mwh-1-5v-lipolymer-rechargeable-battery

 

Hello, Well, they still have, according to the site you attached, problems providing the current for camera flash. That is to be expected. The other issue with these cells is that they are 1.5 volts fully charged, and 1.5 volts fully discharged. That of course means that your battery indicators will not accurately reflect how much juice is left, or how much you started with. The current limiting situation with these cells might also mean you could not, for instance, turn on a 742/743 with a Supercmit plugged in, because the cutoff would be reached. So, you would have to unplug the trans, turn the unit on, and then plug the trans back in, that would of course avoid the current surge. But, they would be great in the LA trans, or erx, slate, etc. 

Sincerely,  Martin

On 12/29/2021 at 7:52 AM, WaterlooNorm said:

Hello. I was recently informed by a highly respected professional that connecting my Wisycom MTB plug-on transmitter to a short XLR cable connected to my boom microphone violates the antenna design commonly used in most plug-on transmitter.

 

"First, I should state that this is the incorrect use of *ANY* plug-on device; no matter what the manufacturer.  Plug-on transmitters employ dipole antennas where one of the antennas are in the transmitter itself, and the other is the microphone attached to the plug-on.  Using an XLR cable between the two breaks the connection and so you have “half a dipole antenna”;  you will not have great RF coverage."

 

I am interested in this group's perspective on topic this as I see this as a common practice.

Normy , I've seen your setup, a 100 meter cable is not short. 

1 hour ago, Izen Ears said:

Great points.  I totally left this info out. We are talking about cart vs bag and those are different beasts.  You’d never put a powermax in a bag haha!  Apologies for the OT, please continue with your discussion.

 

Actually I’m curious, how are you metering these peak vs nominal values?  Aren’t the peaks super fast and hard to measure?  And, why are the peaks important if they’re so momentary?

 

Re: my crap, my uneducated thoughts have always been that at 12 volts my sound cart passes 11 amps, but at 110 volts it’s only 1.2 amps.  Nominal.  But then again I am a dummy and am probably wrong.

Dan, you weren't wrong to chime in. I was just surprised at how much power it takes to run that cart. 140 watts is enough to run 9 Nova's that are running 72 receivers and 9 zaxnets. 

As to your question of peak vs. nominal,  that doesn't have any effect in my world. I just design the packs for the real world power that my system will need for the amount of time that I will need it. The battery distribution system is another conversation, there I did have to design for max current. I cover that by a lot more than 10 percent. Of course there is no battery distribution sytem on Nova, so I did not need to redesign a smaller sytem for the Nova. Just from memory, I believe Nomad with 4 QRX running was about 24 watts. Nova is now about 15.5 watts, about 36 percent less power. That's what led me to redesigning my battery packs, because they can now have about 36 percent less capacity,  yet maintain the same run time. 

I'm pretty sure you're not a dummy. 

Thank you, Martin

2 hours ago, Mungo said:

 

Sorry, misunderstood. I meant compatible to an ENG camcorder receiver slot. Wisy, Sennheiser, Lectro, Audio Ltd, Sony, MiPro, Shure ...

Mungo, Well of course an RX-4 won't slide into anything, a receiver slides into it. But, how many receivers do you get for the 4 watts on a Sony slide in slot? 

Thanks, Martin

14 hours ago, Fred Salles said:

Imho and if your refer to John useful post, I do not think knowing the "wattage" of a particular equipment draws is relevant but you should rather focus on the current it draws when operating. If you follow the ohm law you will understand that the power (watt) will be dependent on the voltage as much as the current. The current drawn by your gear is constant in operation, the DC voltage is not: your battery start maybe to deliver 16v then goes down to maybe 13v few hours later, so if you only read watt it does not tell you what your gear needs.

Izen, measuring the AC line does not give you the current draw of your gear per se because the gear operates in DC. It gives you the power (or current) drawn from the AC power plug yes (and that is usefull if you want to know how much it is going to affect your electricity bill) but our gear has very minimal impact on the main power plug (compared to light for instance). Furthermore you have a converter in your gear that turns the 230 or 110 AC into usefull DC (I would guess 18v). That transformer, whether a transformer or switch converter also uses power. If you want to know how much total DC current your cart draw you should measure the DC current after the converter. You will read a much higher measure than 1,2 Amp.

If your cart has elements that actually use 110v AC power then I guess you have to do several measures, one for AC and one for DC 🙂

Since the original post is about building a battery power pack I assumed Martin's gear is portable and all operating in DC.

Martin you should actually take at least two kind of Amp measures if your build a battery pack: peak and nominal.

Most gear especially digital recorders  draw a lot of Amps at turn on and then get a more or less steady consumption thereafter (actually recorders draw more when recording than idle so you should measure at least at full use: all mike channels armed and with phantom power on and mikes and headphones plugged on).

Once you know the total peak and nominal current draw from your gear you can start build your pack. Most Li-on battery cells or packs have a max peak Amp and a max nominal Amp spec. So you choose accordingly. Most commercial battery pack have higher peak current tolerance than what is advertised. Also if you want to insert a self resetting fuse (polyswitch) in your pack you must take that in consideration, it must not be too sensitive to peak current (not sure about the english words sorry).

 

 

 

Fred, I used watts instead of amps, because I think most people on hear would have thought that I was deriving the amp figure from a 12 volt system, which I don't run and have never run. Mine has always been a 16 volt system. So, if I had listed amperage instead of wattage, I could have mislead someone with what would be a lower number for my setup. Less Amps equals less heat.

The current drawn on my DC mixer is not constant, as the voltage goes down, the amperage goes up. This is why I would use watts. Anyone who knows their voltage can then calculate the number that is appropriate to their own setup. 

My original post, this one, wasn't about battery packs. I was just measuring some equipment because I was curious how much power they needed. For instance, an ERX3TCD uses 1/3rd of a watt. I think I was surprised how low that was. 

My comment about Nova using 15.5 watts with 2 MRX414's running 8 wireless receiver channels did not have analog inputs turned on, because few people will have more than the 8 wireless running, so it didn't make sense to give a value that would not be used much by many people.

I have been using lithium packs with my equipment for many years. I have never had a problem. I have never powered my equipment with anything other than lithium packs. Everybody is different,  this is just how I prefer to do it. I like a pack that will run a nominal setup until lunch and weighs very little, and thanks to building it myself, I can make it into a shape that will fit well into the Nova bag. Thanks to Glenn and Howy, it now appears, that I will be able to run 8 wireless and not do a battery switch until after lunch.

The only wildcard that will be new with Nova is the fan setup. I can't know what that is going to do to battery consumption in the real world. 

I think your english is just great. Thanks for your input.

Martin

17 hours ago, Mungo said:

Slot-In receivers that may be operated in Sony camcorders never draw more than 4 watts. Because the Sony slot doesn't provide more. Major problem for manufacturers to design such low energy devices.

The Zaxcom RX-4 running 4 receivers is 5 watts total, 1.25 watts per wireless receiver, if you want to think of it like that. 

Thank you, Martin

8 minutes ago, Izen Ears said:

Yes it was a clamp meter over the hot, the cable was a special edison cable with the three wires loose (not in housing) so I could isolate the hot.  Is that a lot?  1.2 amps seems like a low draw.  
 

I’m pretty sure the Powermax switches to 100% AC with a trickle charge to the batts, so that reading should have been accurate.  We did it a few times throughout the day and it was the same.  I forgot to try it without the monitors off.

Dan, I wasn't questioning the way in which you arrived at the power figure, I was just surprised at the number on the wattage.  Thank you, Martin

10 hours ago, Izen Ears said:

I’m curious!  Some time ago I tested the full 120 volt draw of my sound cart, by metering the Powermax power cable, and it was 1.2 amps.  So that’s like 120 x 1.2 = 140 watts?  I’m pretty dumb about this stuff and most likely just embarrassed myself haha!

 

Dan Izen

Dan, 140 watts? Wow. So you used an ammeter on the AC line which has given you that 1.2 amp figure?

Thanks, Martin

Hello all, While I was planning the building of my battery packs for Nova, (which I think nobody cared about, ha) I was testing to see how much wattage various components use so that I could build  corresponding battery packs. Does anyone care to know what pulls watt? Pun there.  Maybe I could list the wattage for various components? 

Thank you, Martin

Here is a picture of pack parts.