Radio mics / rechargeable batteries

[djw1981]

How are you finding the battery life?

 

We have a pair of G3 ew100 Lav's, a pair of cheap KAM handhelds (all on AA), and some G1 EW100 lav's (on 9V block). Currently we get 2 services (3-4h of run time) out of each set of batteries before we change them.Would the eneloop's manage that or would we need to charge between use periods?

[cedd]

Inspired by Shez's experience I've just had a very succesful first week of panto using rechargeables.

 

I decided to properly go for it, so I bought 64 Eneloop's and a pair of 16 way chargers (Japcell). Big investment but it'll pay itself back within the year in battery costs.

I've divided the batteries in to 2 sets and have coloured them in with sharpie to make sure there can be no mixing up. Each battery also has a small number written on it for tracking any issues should they occur.

Eventually the chargers will live in a case with a pair of 12V lead acid batteries and a charger/changeover circuit so that if a helpful caretaker decides to switch off my sockets, they'll still get a charge. Currently I've just got them plugged in to a UPS.

So far so good! I've noticed they drop off of the "battery full" indication quicker (as Shez describes) but so far not had any fears that they weren't going to make it through the show. I'm yet to run an experiment against a standard cell to see how long the trantec transmitters will run for, but they have plenty left on the meters when they come back. I've also changed my battery regime - they now get a fresh battery for every show, rather than doing 2 shows on a single battery. As I always test my mics before each show anyway this doesn't really add any extra time to the whole process.

Not had any stuck batteries in the Line6's either. A few needed a gentle hit of the pack to persuade them out, but nothing like the pliers job that some alkalines have been.

Also I'd say the indicated run times on the Line6's has been better. I had some that were coming back from a single show (2 1/2 hours) indicating no battery remaining when I was using alkalines. Not the case any more.

 

Only negative comment is that the recharge time is a little longer than the length of a show. This means that when I've got back to back matinees like this weekend (1 and 5.15 performances) I have to make sure I get a set of batteries out of the mics the night before and on charge ready for the second show, because if I put them in at the start of the first they won't be ready in time. This hasn't been an issue in this venue (which has the bar open for a good hour afterwards, so no caretaker or crew rushing to get you out on a night) but may be in others. I can see myself buying a third set and maybe making some 3d printed battery holders in the case with the chargers so I've somewhere to store the next charged set.

 

I still have a box of a hundred AA's with me which I'll keep for emergencies, but I don't think I'm going to need them.

Thanks for the tip Shez. My conscience is much clearer after each show and I'm sure my bank balance will feel much happier too!

[allanr]

Revbobuk mentions using 9V block batteries (aka PP3) and that he uses a Lidl charger. It's worth mentioning that the Lidl PP3 battery (Tronic) has a nominal voltage of 9.6V (8 cells) which is a good match for the standard single-use alkaline 9V battery. Capacity is 200mAh.

 

Most other rechargeable 9V blocks are actually 8.4V (7 cells) which can result in shorter than expected duration on equipment which is picky about supply voltage.

 

I use them with good results in my EW Gen-1 handheld mic.

[Yorkie]

At church we have a variety of Ch70 Sennheiser EW packs and handhelds. Bench tests with the twin AA beltpacks show that we can get 8h30 out of 1800mAh NIMH's in those which is great. Bench tests of the 200mAh 8.4V PP3's don't even make it to 2 hours so we're after different batteries. Anyone particularly recommend a reasonably priced and truthful supplier of the 9.6V 230mAh PP3's? Will we get 5 hours out of them and do we need to get a special charger to cope with their voltage? Hoping someone can advise before we spend £30-40 just to test it out.

[adamantiumxt]

I also recently switched to using rechargeable AAs for our trantec transmitters in school. I bought the 2600mah LADDA batteries from IKEA (which are apparently the same as Eneloop Pro, but are far cheaper. They also have the bonus of a large matt white surface for marking on) and a Vapextech charger (microprocessor controlled and charges cells individually, not in pairs). Haven't done any proper tests for battery life but they should last ages considering trantec say the energy consumption of the transmitters is 40ma or something, but I charge them between each use. In general they are only used once a week but we keep them in the charger for the rest of the week and it hasn't caused any problems so far.

[allanr]

+++ PP3 VOLTAGE ALERT +++

 

My previous reply (#18) suggested Lidl's Tronic PP3 batteries because they were rated at 9.6V 200mAHr. I say 'were' because I see they're back in stock at my local Lidl this week, but the packaging now states 8.4V, 220 mAhr.

 

I thought the previous higher voltage (but lower capacity) version was more useful.

[Simon Lewis]

Simon, for your "lazy" users have you considered a Sennheiser L2015 with BA2015's? We use these all over our campus and would easily work for your application. G2 300/500 or G3 packs can be dropped straight into the charger without removing the batteries - lazy enough??

 

Sorry - I missed your comment when this thread was active! - The users I am considering use a variety of radios - some Sennheiser EW beltpacks and hand helds but also Sennheiser XSW, Shure, Trantec, Line 6 and TOA.

I suspect too that even where the users do have EW series beltpacks, the additional cost of the specific Sennheiser hardware might appear somewhat prohibitive!

 

 

 

[cedd]

Here's a photo of my charging setup;

 

Gives 32 ways of charging in a peli case. Under the chargers is a 12Ah battery and a UPS and then there's a powercon in the left hand end of the case. The UPS helps mitigate against building caretakers who like to switch off everything with a light on it, or tech power supplies that are switched off at the end of the night.

 

Future improvements will include a pair of thermostat switched fans so that I can close the case when it's running safely, and also a second stat that'll shut down the chargers if the temperature gets too high.

That key switch isolates the battery from the UPS - it's just a pcb so there's no on off switch on it otherwise.

 

So far so good. The UPS is a little noisy (as in, switchmode whining) so I tend not to run the thing while a show is going, just because I can hear it and it puts me off.

The blue boxes are ex ammo boxes for individual rounds and hold 50 AA's each. I've got 2 of them in this box. One is marked "used - to charge", one is "Charged" and the third is my box of emergency alkalines.

I have 2 sets of 32 Eneloop batteries, each set being coloured in a different colour with sharpie. They also each have a number written on them very small. Once I've got my new radio racks standardised I'm going to label each bay on the chargers to correspond with its' own beltpack to aid battery changes and make sure I don't miss any.

The Japcell chargers have been really good so far.