Rechargable batteries for wireless mics?

[Bryson]

So, I'm looking at the giant pile of 1/10th used Procells that I need to take for recycling and wondering: Are rechargables finally good enough for wireless mics these days?

 

If so, any recommendations? We use AA and 9Vs

[pete10uk]

We ues and have done for 10 + years AA rechargeable batteries in our Sennheiser G3 kit. Never had an issue, some of our current batteries are coming up to 8 years old now and show no signs of lowering performance. We store them charged, and once a month ish run them all through a charger on slow charge just to ensure all are full. We use them and get at least 5-6 hours out of them and then charge again.

 

The only slight downside is the battery meters are off because of the voltage difference! When freshly fully charged you get all 3 battery bars but they soon drop to 2 bars, they remain on 2 bars for 5 or so hours then drop to 1 bar but then only last 15 min. I just end up changing every 3 hour or so in breaks.

 

The key I think is not to fast charge them unless you need to for turn around times. I have many uniross hybrio 2500 mha batteries which are the older ones but have our last lot about 2 years ago we're some gp 3200 mha ones which are fine.

 

The charger we use is a powerline bcl-1000 or something like that.

[paulears]

I'm not really sure rechargeable batteries have ever not been suitable for radio mics, because the real problem has always been unreliability. The critical factor is management. The problem I'm sure we have all had is where you stick a set in and then fifty minutes into a one hour show, they fail. Accepting a few properly faulty cells with reduced capacity or performance, the real killer is charging. One of my regular ASMs is a bit obsessive with battery charging. Work tops taped out. Labels, times, coloured stickers, I'd numbers, records etc, and takes lots of flack. However, none of her various types of batty have ever failed during a show.

 

A long time ago now, when I was doing lots of communications stuff for the emergency services we did a report on failure rates on personal radios and the key result was that the charging process was the failure point. Somebody came in off shift, put their radio on charge, and then somebody took it when they needed a radio, only an hour later. Sometimes chargers would have batteries on them and be switched off because somebody needed the socket. Sometimes people would notice hours later and turn it back on and then suddenly ten people ran in and took radios that were only part charged.

 

Chargers that have red and green charge lights rarely sense charge states accurately, especially when the batteries being charged have different cycle counts. I've noticed brand new modern cells now retain charge longer, and seem better able to maintain their output.

 

If you can initiate a reliable charge routine I think it is now perfectly feasible. The snag would be you'd need chargers that are labelled in time, so if you are doing two shows a day, then two chargers labelled show 1 show 2 etc, so the part used ones go onto the right charger, so they have time for a full cycle. My main sound guy relies too much on battery meters, and we have failures on ordinary batteries, because he is convinced the meter is right, and me the pessimist simply don't believe them. I've lost count how many times my voice appears on the comms saying "purple mic says ten mins" and getting a "it said it was full at the start"

[pete10uk]

I agree here with Paul all the way. My take on it is not to label and record endlessly but to charge before they go out and when they come back in every time, doesn't take long if you have a couple of good charges and swap the batteries every time you pass and they are done.

 

I don't try to rely on charging between shows, I take enough batteries with me to swap every 3 hours, but that said I'm not doing show after show after show. It's what ever works for you.

[GaryNattrass]

In 36 years of broadcast I have never used rechargeable batteries as I was told the 1.2 volts can potentially affect the transmission and reception range, reliability is also a factor so we always go with std type batteries.

[timsabre]

In 36 years of broadcast I have never used rechargeable batteries as I was told the 1.2 volts can potentially affect the transmission and reception range, reliability is also a factor so we always go with std type batteries.

 

All the mics which take AA cells use step-up power circuits so 1.2 or 1.5V doesn't make any difference in terms of actual radio operation. The 9V ones tend to be regulated down so that doesn't usually matter either. The main problem is the battery level detection which as Pete said above, doesn't work properly any more, and when you get towards the end of the battery the mics tend to go from "ok" to dead very quickly.

[peza2010]

For me its just really not worth the hassle.

 

I have enough things to lose sleep over at night without worrying about if my batteries have had a full charge.

 

We just buy good batteries in bulk at a good price, and never push our luck with battery life - changing them at coffee breaks etc if its a corporate show - or for rock and roll fresh sets across the board a few minutes before showtime, then use the remaining life to soundcheck the next day.

 

If you ask the right people you wont need to worry about recycling too much either - We have a batterie collection box in the warehouse but a lot of the time the used batteries get taken home to feed remote controls/ xbox controllers.

[pete10uk]

For me its just really not worth the hassle.

 

I have enough things to lose sleep over at night without worrying about if my batteries have had a full charge.

 

Then you want shooting. If your changing batteries without using them completely or not using perfectly good rechargeables because it's easier, in my opinion you don't deserve a ticket on the delicate ride which is planner earth!

 

That's just my opinion but in it's hard to justify otherwise if you look at the long game.

[Shez]

Must be time to post up this case study again about Wicked at the Apollo.

Rechargeables can be perfect in that environment with regular usage and a well managed charging schedule but if your usage is sporadic (as mine is) and they may sit unused for a couple of months, it's rather less practicable.

[Bazz339]

I am sure with the right chargers and a reasonable charging regime re-chargables are a valid option. The capacity of the batteries and sophistication of the chargers has increased greatly.

 

When I last tried them many moons ago the thing that put me off was that the capacity was not quite enough to safely cover a show and as Paul said the fall off time from low warning to shutting off was very quick.

[Jivemaster]

The only barrier to using rechargables is the need for the OTT obsessive perfect charge regime.

[chelgrian]

So, I'm looking at the giant pile of 1/10th used Procells that I need to take for recycling and wondering: Are rechargables finally good enough for wireless mics these days?

 

If so, any recommendations? We use AA and 9Vs

 

http://www.ansmann.de/en/products

 

Expensive but you get what you pay for in battery chargers.

 

As other have said rechargeables are fine with good battery management. Rechargaeables don't last forever cells do have a definite life after which they fail to hold charge so you do need to plan that in to the investment.

[paulears]

I suppose the question is how much is show reliability worth?

 

This is the quest, and things get in the way. Batteries are rarely free or a cost that can't be recovered . They go on contra accounts, they get billed to hirers, and the cost of going to rechargeables is high when you add in chargers and the two or three spare sets - plus you then lose your income stream from being able to charge out more than they cost!

[peza2010]

For me its just really not worth the hassle.

 

I have enough things to lose sleep over at night without worrying about if my batteries have had a full charge.

 

Then you want shooting. If your changing batteries without using them completely or not using perfectly good rechargeables because it's easier, in my opinion you don't deserve a ticket on the delicate ride which is planner earth!

 

That's just my opinion but in it's hard to justify otherwise if you look at the long game.

 

Okay calm down satan ?.

 

For me its simple - if my radio mics fail on a big corporate job I dont want to have to explain to my boss that client x wont be paying their bill because I was tight with batteries.

 

There is place for rechargables, personally for me that place is not radio mics.

[richardash1981]

As other have said rechargeables are fine with good battery management. Rechargaeables don't last forever cells do have a definite life after which they fail to hold charge so you do need to plan that in to the investment.

I have been running on 9V 200mAh GP Batteries from CPC for a while now, the most recent one being one of these. I prefer my radio mic kits on rechargable to using dry cells, because I can start everything I do with fully charged batteries. A lot of these events are only an hour or so and volunteer run, so using a new battery every time just isn't viable. then you get into trying to keep track of how many uses you get from a battery and so on. This works because they are my mics and my batteries, so they go on charge before I take the kit out each time. I have spare dry cells to put in if something goes wrong (like I forget to take batteries out of the charger), but they tend to go out of date rather than get used up ...

 

Some old/cheap betpacks did put out less power on a rechargable (8.4V) than on a new dry cell - but always rather more than on a dry cell at the end of it's life, when the terminal voltage of a nominal 9V battery is down to 7.5V! Any decent transmitter should now have a DC-DC converter which will stabilise the supply so that the output is constant.

 

Not trying to charge very fast is good advice, although I have struggled to find a multi-9v charger with a sensible rate - most either charge at a very low trickle, or are abusively fast (the many forms of this are in the latter camp at 2 hours!). I'm currently using this one but would like a 4-way 9V only version if I could find one.