How to change some batteries in under 10s
I know this might not seem the most impressive thing but how many people could actually change the batteries in a device they have this quickly? It definitely takes my wife longer than this to even get the battery cover off the TV remote.
Some backstory
As I have alluded to many times my full time job is working as a Theatre Sound No. 1 on a show in London. For the majority of my time I am on the desk mixing the mics. But for a couple of shows a week I cover the off-stage sound track. This means I am responsible for prepping the mics before the show, testing they all work, fitting them on the actors, swapping any shared radio packs between actors and monitoring the health of the packs. Normally it’s a pretty straight forward role. However, the complexity comes from one of the actors only spending about five minutes off-stage for the whole two and a bit hour playing time. And, of course, this actor’s battery dropped to 20% (1 bar) five minutes after we had started back from the interval.
The kit
The hardware
We have a slightly unique setup with the show being housed in a Grade II listed building with extremely thick walls and a lot of marble. Due to this the travel of the RF doesn’t travel quite as far as you might hope. So to fix this we have two complete systems (pairs) of Shure ULXD4Q receivers each with their own antennas. And because everything lives on the network we can both monitor date using Wireless Workbench and receive audio for monitoring in WaveTool from Dante. It’s not an ideal setup, but it’s making the best of what we have.
The batteries
We use the Ikea LADDA 2450mAh batteries. I know this might be a slightly contriversal choice which is why I am going to explain here why we chose them. Before COVID-19 hit we were using Duracell rechargeable batteries and these were great when the were new, but we had been noticing quite a rapid drop off in the run time we were getting. After about a year of use they were getting hit-and-miss whether they would last the 5-hour call for a show. This lead to us having to swap batteries during the show increasing our reliance on disposable batteries. This is both bad for the environment and the budget. When we reopened, and we found that our almost new 3 sets of Duracell’s (48 individual batteries) had all seem to have suffered damage (probably because they had been dead for 18 months) I decided that it was time to try something else. After some research some people really liked the fischer amps batteries but at more than the Duracells I wasn’t keen. Another option would be to get the Shure lithium-ion batteries, but this would have required getting a new charger and changing the rack which we didn’t have time to do. In the end we went with the Ikea batteries because we could get an extra 16 batteries for the price of 3 sets of the Duracell’s. The capacity of the batteries was slightly lower, but I figured that with the reduced price we could just get the extra set and change them every show. What I was not expecting was for them to out last our current batteries by a long way. Brand new I would almost risk using them for three shows (about 15 hours run time) and we only dropped to using them for one show after about nine months. I feel like there is quite a bit more I could say on our batteries, so I will stick a link here if I do.
A small digression
I did a stint of about four years working aboard Royal Caribbean cruise ships. There we had a lot (read excessive) of the Shure UHF-R series. And, as it never broke, I never felt the need to take photos or write anything down about it. From memory, and after trying to research to find the parts I’m starting to wonder if I am remembering wrongly, we used four antennas through the theatre (2 in the wings and 2 at the mix position). These four antennas then fed a series of active diversity combiners and distributors that first compared the Stage Left wing and mix antennas and then forwarded the best on as the A antenna for distribution. A similar process then happened on the right side. However, I have not been able to find any reference to a diversity antenna combiner, so this may all be fibs.
The prep
The first part of getting the batteries successfully changed was to talk through with all the parties involved. After a quick discussion with the Company Stage Manager (CSM) to weight up the risk of not changing the batteries. While 20% in theory was enough to get the mic to the end of the show, we have always found monitoring in that last bar less accurate. We have seen mics last for over an hour and some die completely in 20 minutes. With another 40 minutes left of the play we decided to go ahead with the swap.
The actor has two costume changes during the second part of the show. So the first thing to do was to make sure all the off-stage staff were on the same page. A quick radio to the Deputy Stage Manager (DSM or show caller) to say “Hey we’re going to go for a battery swap, the actor maybe slightly late for their last entrance. We will confirm the cue light once the change has happened.”
Next I ask the Assistant Stage Manager (ASM) to notify the two cast members that are likely to be impacted most that there maybe a slight delay to the scene resumes. We also let an actor that I am normally swapping a pack to at that point of the show that I will be with her later, but as she has a long time before going on this is less of a problem.
The final off-stage person to check in with is the wardrobe dresser who will be doing the quick change with the actor. I explain that we will be doing a battery swap, but she should go ahead and do the quick change first as its more important for the actor to be dressed as the current batteries have a chance of making it to the end if we have to rely on them.
The final part: notifying the actor. Now this actor is one I have worked with before. He was in the cast we had before the show closed for Covid and such I knew him quite well. This was a large factor in deciding to change the batteries, if I hadn’t known him so well it might have been a “Hey your batteries are low but should get you to the end of the show.” Rather than what followed. And this is how it went down.
Me: Hey Owen. This isn’t going to affect you for Whiskey Chamber (the next scene) but your batteries are low. We’re going to swap them after your quick change out of Limehouse (the next time he comes off-stage).
Owen: OK. What do you need from me?
Me: I just need to know where your pack is now.
Owen: indicates to where his pack is and heads in to Whiskey Chambers
This chat happened after he had done his quick change and was walking from one side of the stage to the other.
The swap
So everyone who needs to know is aware that the swap is going to happen. I have taken a brand-new set of Duracell Industrial batteries (I would probably have reused a set if the actor hadn’t been one of the five top billing actors) that I tested in the spare pack to ensure that they were definitely full. All that is left now is to do the swap.
Owen comes sprinting out of the Chamber (stage) and does his quick change as normal. He then raises his arms and allows me access to his pack that is tucked under his shirt. So now its down to me. First thing is to untuck his shirt and remove the mic pack from the Velcro pouch that we use to hold them. Open the battery cover, take out the old batteries, put the new ones in and put the pack back into the pouch. Nice and simple hey?
It’s not actually that hard to do. The hard bit comes from doing the swap under the pressure of a live show. I can hear the scene change music and know that it is starting to run out. There are two actors who would usually be onstage by now getting a little agitated as this is out of the norm. And finally there is the CSM who came up to hover on the off chance that she will have to stop the show if this goes wrong. I put getting the change down quickly and successfully down to a few key points:
- I know the actor well, and he trusts that I have his and the show’s best interests in mind with the call I have made.
- I know the hardware well, I know that both AA batteries sit in the pack - ⇾ + left to right in the pack.
- I know that the pack may not turn back on after I have removed the batteries, even though the power lock is on. So I plan to toggle the power switch whether the pack comes back on this means the power will lock on when I hit the correct position.
- I am the highest and most experienced person in the technical chain, on-site. At the time my Number 2 was fairly new, and while she had quite a lot of experience, she may have second guessed herself when asked to justify it to the CSM.
After the show I checked in with the DSM, and she said we added about 10s to the timing breakdown for that scene from the average runtime. This is actually less time than if the scene change goes poorly. The only thing that went wrong during the swap was that the other actor waiting to go in decided to be helpful and confirm the cue light while he was standing around waiting. Luckily, out of the corner of my eye, I saw him do it and was able to radio the DSM to let her know that we weren’t actually ready yet.
The gist
What this boils down to is to know your kit, the people you are working with and to follow your gut. Yes those batteries may have made it to the end of the show but if they hadn’t then it would be much worse for Owen as he would have had to push harder at the end of a long show for him.