Rechargable batteries for wireless mics?

[fincaman]

Hello I posted about this in 2011 and was jumped on by almost everyone sometimes in quite aggressive ways. I tried to say how good rechargable li-ion PP3s were and how much money they could save especially if you were buying your batteries retail which most small amdram/cabaret/churches do. I can't remember anyone agreeing with me mostly talking about charging routines andsaying they weren't safe One reply from CEDD said "I Never Will Try Them".I am still using the same li-ion batteries to this day and they have saved me 1000s of pounds. I have never had a failure and still get 12-13 hours from a beltpack. I am about to do a survey on AA/AAA both alkaline and rechargeable putting them on a 40-50 Ma discharge to see how long they last. I'll report back

[dmxlights]

I was not going to jump in and give my cent/penny worth as mainly do lighting at shows me and a friend does. He is the sound tec and he has been using rechargables for a good few years now would be AA and they are GP batteries at about 2300mah. We have done 2 shows on them with no problem at all on a full charge it would be about 8 hours in total. The chargers are a 8 way and a 12 way that charge each cell on its own and we never had any bother with them.

[pete10uk]

Hello I posted about this in 2011 and was jumped on by almost everyone sometimes in quite aggressive ways. I tried to say how good rechargable li-ion PP3s were and how much money they could save especially if you were buying your batteries retail which most small amdram/cabaret/churches do. I can't remember anyone agreeing with me mostly talking about charging routines andsaying they weren't safe One reply from CEDD said "I Never Will Try Them".I am still using the same li-ion batteries to this day and they have saved me 1000s of pounds. I have never had a failure and still get 12-13 hours from a beltpack. I am about to do a survey on AA/AAA both alkaline and rechargeable putting them on a 40-50 Ma discharge to see how long they last. I'll report back

 

I've found the same. There is absolutely nothing wrong with rechargeables and hasn't been for a decade or more, were not on Ni-Cad's anymore!, yet people have a hang up on them and get quite protective of not using them.

 

Could this be because of rumours spread by the big manufactures? I think it might be you know.

 

Again I have some of the same batteries I have had for 8 years and have never had an issues, they won't last the 8 hours procells will, but they will do 6 hours every time in Sennheiser G3's, I would never use them over 5 hours and probably will change them at 3 - 4 hours dependant on the breaks. but this is reliable. The only downside is the lack of proper usage meters however this could probably be addressed by the manufactures firmware.

 

Sennheiser do a rechargeable pack for G3's, Here to me this is just a couple of rechargeable AA's with the firmware recalculating the meters when the plastic housing is detected? The question is how to you get the G3's to think your using an official back so the meters work correctly?

 

I don't accept that you need rigorous charging regimes, as said, I charge them after every outing and before an event if they haven't been out for a few weeks. all I do is keep them in a plastic 4 way battery box and when they have been used pop them in to it alternating ways which means they need charging.

 

I am the boss in my world and my customers are the most important thing to me, so the comments about explaining to the boss when something goes wrong doesn't wash nor does the loss of revenue of selling batteries, in this day and age should you be selling batteries when there is an almost free alternative, I've saved myself and my customers £1000's over the years and in return my customers keep coming back for more, arguably because of the savings over my competitors and / or of green credentials of using rechargeables.

 

If we jump forward a decade or 2 cars will be battery powered, houses will have batteries charged from micro generation and the whole battery thing will be everywhere. It is the future, now lets jump onboard and save the planet 1 AA at a time!

[Shez]

Could this be because of rumours spread by the big manufactures? I think it might be you know.

I'm not so sure. It certainly isn't the case for me. My usage is sporadic and not heavy. I've used them a lot with loaned out compact cameras for many years, starting with NiCads and now with NiMH. Even with new batteries, I've seen a few issues that would make me nervous. Discharged too far for an intelligent charger to recharge them, inconsistent running times, some cells sitting in the charger for hours longer than others and never reaching full charge, etc. This is with decent Ansmann batteries and a good charger of the same make. Some of these issues can be managed out I'm sure.

 

I think the real problem is fear of the unknown. Take a pair of AAs out the box and you know you'll get 6/8 hours out of them without thinking about anything else. Rechargeables need more planning and ideally some dry runs to find out how long they'll last and what the battery gauges show. Some are also just too big to fit in the battery compartments - it really should be a standard diameter but it seems that it isn't. Alkalines are just easier. Plus there's the initial investment in cells and chargers; it will of course pay for itself in the long term but if your usage isn't heavy, it'll take a while.

 

Personally, I'm open to the idea. Spurred on by this thread, I put a couple of 2500mAh AAs in a G2 TX this morning and have been watching how it lasts. It dropped to two bars in less than an hour but is still on two after a total of 5.5 hours so far. Easily enough for one show. I'm going to get a few fresh cells to try out in panto next week. I don't foresee any problems in the short term once I've figured out the charging cycle and what state to leave them in for storage. Longer term - that makes me more nervous. Will they work just as well straight off or will they need a couple of charge/discharge cycles to get them back to their best? I suspect it would only take one failure at just the wrong time to put many users off.

[Jivemaster]

It's plain that rechargeables have improved, A nicad PP3 used to be 80mah, now a modern PP3 rechargeable is 200mAH. If you use one at a meeting there is little saving but if you have 20+ on two shows a day then with a suitable recharge regime there is money and environment to save. Gone are the days when it took 2AA cells to power a personal cassette player there is no use for part empty primary cells

[pete10uk]

Could this be because of rumours spread by the big manufactures? I think it might be you know.

I'm not so sure. It certainly isn't the case for me. My usage is sporadic and not heavy.

 

Newer cells are about 3 times the cost of good standard AA's and you can pick up a standard charger for next to nothing. They now only loose 20% charge a year sat on the shelf.

 

Some of mine are 8 years old and I have no rotation on how they are used, some they may only get used only a few times a year, especially the older ones as I tent to reach for the newer ones by default as the old ones are only 2500mAh and the new ones 3200mAh but sometimes they are all used with no issue.

 

So lower sporadic use should still give a return relative quickly.

 

Correction to my last post my current batteries are 2600mAh I did have some 3200 but these were only available for a short while and I sold my stock on with some second hand microphones.

 

Batteries

 

Very Basic Charger for low usage

 

That’s £14 inc vat for the equivalent of around 3000 normal batteries with a 5 year guarantee on the cells!

 

My charger of choice

[chelgrian]

The only downside is the lack of proper usage meters however this could probably be addressed by the manufactures firmware.

 

In anyway accurate usage meters are absurdly difficult to implement as it depends a large number of factors and requires individual discharge profiling of the cells in question, knowing what battery chemistry is in use and having models of what it will do under different current draw profiles and it requires knowing the cycle count of the cell and myriad other things.

 

On a side note I absolutely do not condone using Li-IoN batteries in standard cell sizes as some others have recommended in this thread. Both charging and discharging such batteries is inherently hazardous and can cause thermal runaway and fires. Almost all devices which have Li-IoN cells have smart batteries which contain temperature and other sensors which communicate with matching charging devices.

 

You just have to look at Samsung and their Note 7 phone catching fire as to what can happen. Now imagine this happening to a radio mic beltpack on a performer.

 

This is why reputable suppliers only sell NiMH in standard sizes.

 

Sennheiser do a rechargeable pack for G3's, Here to me this is just a couple of rechargeable AA's with the firmware recalculating the meters when the plastic housing is detected? The question is how to you get the G3's to think your using an official back so the meters work correctly?

 

We had some of these and the charging sleds. We had great difficulty with them either failing to charge or prematurely ending charging when the cells were not actually full. We ending up sending them back.

 

I don't accept that you need rigorous charging regimes, as said, I charge them after every outing and before an event if they haven't been out for a few weeks. all I do is keep them in a plastic 4 way battery box and when they have been used pop them in to it alternating ways which means they need charging.

 

That is a rigorous charging regime by the standards we are talking about. For reference at British temperatures a NiMH battery will self discharge to about 50% of its original charged capacity in about a month. The discharge rate is higher the higher the ambient temperature.

[cedd]

One reply from CEDD said "I Never Will Try Them"

Hold on there just a second. Quoting people out of context is a pretty dangerous thing to be doing, especially when that comment was one of 4 posts they made in that thread outlining their position. Complaining about people jumping on you in quite aggressive ways and then going straight in to a quote from me also very much implies that I was one of the ones being aggressive. I've read all of my replies on that thread and don't detect even a hint of aggression.

 

Here, for the record, is my full reply. Please note especially the last sentence, which I hope implies very much my lack of aggression and the fact that I saw this very much as a civilised technical discussion.

 

Nope! And in my line of work, I never will. Firstly, I'm a Trantec S5.3 user. That means one battery per pack, for at least 2 performances. So my battery costs are already pretty low. Secondly my work is very seasonal. I can go a good few months without touching my mic racks, then have 3 shows back to back. It's far easier to stick an order in a week before for a tenner's worth of batteries (80 AA's, 160 performances) and have them arrive knowing they're all new and good, than have to worry about sticking them all on charge, making sure they've been looked after during the quiet period. All that malarky. In short, for me, rechagables don't work and aren't worth the investment. If they work for you then that's great, but quite a few other people have already said "not for me".

That was in reply to your question of if I'd ever used Li-ion. I don't want to do death by quote, but the original thread can be found here; http://www.blue-room.org.uk/index.php?showtopic=49891&st=0

You'll see my replies talking about a friend's very real and serious experience of coming to a theatre to find a set of flat batteries because of the caretaker turning the power off overnight. You'll also see a reply where I talk about having changed my disposal regime to start recycling them and finally a reply talking about my battery change regime. It was all a very civilised conversation from what I can see and whilst a lot of us begged to differ (as has happened in this thread) I believe everyone parted company on good terms. I still therefore find it a little concerning that my name was pulled out as being worthy of an out of context quote.

Things do change though so I definitely think it's worthwhile refreshing this topic. The wellbeing of the planet does concern me and I'm genuinely open to being persuaded that rechargables are a better way forward. One barrier has been time - volunteer-run theatres aren't great at opening up hours beforehand, and once the cast are gone they want the place locked and to be on their way home. Taking batteries out of belt packs at the end of the show (especially when you're running 24 radio mics, with a mixture of 2 and 1 battery per pack), putting them on charge and then repeating before every show is additional time that some venues in particular just won't let me have. Having 2 sets of batteries would solve that problem - I could leave them in overnight, but still I'd need to do one change per show, whereas with my S5.3's I easily get 2 shows out of a change currently.

 

Question marks about battery monitoring accuracy raised by others aren't a major concern for me - my receivers live under the stage anyway so I can't see them during a show, and if you mess up a swap then all accurate monitoring is going to do is buy you a bit of time before you find out anyway when the pack stops working. My current regime gets around this by discharging the batteries in the packs fully overnight - I can't start a show on an empty battery therefore - the pack wouldn't switch on long enough to let it be tested.

 

One thing that does concern me as a buyer of cheap batteries is the ethics of the company I'm sourcing from - if it's such a cheap product to buy then who is suffering down the supply chain? Are workers in a mine somewhere being put in danger? Are staff somewhere inhaling toxic fumes? Are rivers somewhere being polluted by a factory? I suspect, sadly, that the answer is yes to a lot of those questions, but I also sadly suspect that the same would be true if I was buying el-cheapo GP Alkaline or Duracell's top brand. I'd love to see some research on it so I was better informed, but I can't seem to find much.

[Bobbsy]

If you're really worried about the 1.2 vs 1.5 volt issue, you CAN now get rechargeable AAs rated at the full 1.5. However, as with others, I've never had problems with the 1.2 volt batteries used in a variety of Sennheiser and Sony mic systems.

 

What I do agree with though is the need for a totally OCD charging regime. I'm paranoid enough that I'd keep a set of Alkaline batteries locked in my desk "just in case".

[timsabre]

Just to jump back a few posts...

 

On a side note I absolutely do not condone using Li-IoN batteries in standard cell sizes as some others have recommended in this thread. Both charging and discharging such batteries is inherently hazardous and can cause thermal runaway and fires. Almost all devices which have Li-IoN cells have smart batteries which contain temperature and other sensors which communicate with matching charging devices.

 

You just have to look at Samsung and their Note 7 phone catching fire as to what can happen. Now imagine this happening to a radio mic beltpack on a performer.

 

This is why reputable suppliers only sell NiMH in standard sizes.

 

This is completely not true, Li-Ion batteries in standard cell sizes already have battery protection circuits included to protect against short circuit, over charge and over discharge. There are plenty of "reputable" suppliers of Li-Ion AA cells for example.

[paulears]

If I put in a brand new and long end dated AA of reputable brand it works. Manufacturing faults happen but I've had just one I think. If rechargeable are as certain I'd be happy but they're not. The good ones are very good. We seem all happy with that now. My problem is the human element. A big box of charged ones for example. Charged last night or the ones charged last week still at the bottom? I have no idea how to implement a 100% reliable system. With one person running the entire show then I suspect it's doable. Days off, crew swaps, helpful stage management all work against reliability. It's people not the product!

[Mr.X]

I have no idea how to implement a 100% reliable system.

It's incredibly easy, really.

Just store your batteries in the charger. Take only batteries that are fully charged from the charger and use them.

Any batteries that are not in the charger are unknown. Put them into the charger.

Write on each battery with a sharpie or thin sticker a number. Once a year use a charger/analyzer on each battery and make note of the mAh of each battery, identified by it's number. Throw away the ones that have a capacity too low for your usage compared to the battery's rated mAh. (for me that's 50%)

 

I'm not sure what's so hard about that!

 

Incidentally, I've had WAY more problems with "new" alkaline batteries (fresh from the box) being DOA than a rechargable dying. I can't remember ever having a rechargeable that I maintained fail on me. I've had brand new Energizers and Procells have come out of the box dead. Don't get me started on batteries that weren't from a sealed box. Hard to verify an alkaline battery but very easy to verify a rechargable.

[paulears]

What's hard? The requirement for multiple chargers? Most people have more cells than charger slots. If you don't have enough charger slots you have a tray perhaps - maybe labelled nicely - FLAT and another - FULL, but this has never been reliable when multiple people are involved. I can only go from my own experience of charging regimes. Perhaps I just take less care than I should, but having a box of batteries that all have different analyser results, and keeping track of all this drives me mad. I do this on my video batteries, and on these I write the running time, which means they all have something sensible on them, but even with 3, 4 way chargers, from time to time somehow a full one turns out to be flat. Perhaps I'm careless, or maybe just busy?

[Andrew C]

It's incredibly easy, really.

 

If you re-read Paul's posts, he's quite clear - easy if you are the only one involved. Try to imagine a big production, with many radio mics, being swapped between cast members by different crew on different nights/matinees...

 

You might start to see the problem.

 

That said, if it were me, I'd make a dispenser. Freshly charged batteries go in the top, take them out of the bottom only.

[paulears]

I like that idea-Patent it quick! Actually a brilliant solution