When I first built my short-lived fursuit, Larry, the Lab Rat, I wanted to have moving ears. So, I found this thing on the internet called NecoMimi ears. They’re ears that move according to your brainwaves.
They were incredible. They operated by using a sensor on your temple and one hooked to your ear. The ears would move depending on your mood. Well, it kind of worked, either that or my brain is really jittery. Either way, the ears would move down and they’d shoot back up. It was great! While I had it working I went out several times with my friend Aly all dressed up as a rat, complete with tail. We went to the mall, walked around Old Town, went to Sprouts. It was awesome.
However, it had some problems. I had to embed the thing into my rat head. Even though the head was close to my head it was difficult to get the device on. For one, it was hard to access the batteries, for another we had to make sure the ears were clear. However, I needed the batteries to be external to the head. I couldn’t change the batteries while it was in my head, and it would be easier if I could connect batteries externally.
My half-brother Ian suggested I extend the battery life of the device if I was going to put the batteries on the outside. I discovered that if I add more batteries to the circuit, anywhere on the circuit, that would extend the life of the necomimi.
I kind of kept it to myself for two and a half years, as the whole thing wasn’t too amazing to me, but I guess it’s kind of amazing! The batteries lasted for hours, hours, and hours.
This work requires soldering, so if you are unfamiliar with soldering or don’t have a soldering gun you’ll have to catch up or get new equipment. Here is a tutorial on soldering from SparkFun.
Here’s how I did it:
First I got together some glue-gun rods and a little copper plating. These were going to serve as my fake batteries. Here are a few pictures of the copper plating on the rods. You want to drill a hole through the battery encasing to stick the wires through. Here are some pictures:
Here are some pictures of the bricks:
The bricks serve as snap connectors for the circuit. But how does the current get to the snap connectors? Simple, ribbon! You can get a ribbon wire that acts cloth-like from SparkFun. It’s like a wire, but it’s generally safe to weave through clothing and other crafts. Here’s a picture of the wiring (encased in electrical tape):
You’ll see the ribbon wire has three wires: positive, negative, and ground. Strip the wires out and attach a snap connector to the end and voila, you can snap two ribbon wires together. (Make sure they are made to face the opposite way if you connect them facing the same way it could short circuit) Be careful to make sure you put negative where you want it and positive where you need it.
So now, we got fake batteries with copper plating in the battery pack, as well as a hole drilled out to allow for wires to go outside of the case. These are attached to a brick so that we can snap on additional ribbon wire onto it. This was then put into the head with the necomimi ears.
Then, we built an intermediate cloth/wire with more of the ribbon, putting two bricks on either end. That gave us a pathway that we could extend the ribbon cord down my back. Why down my back, well, the rest of the batteries of course. Here is a picture of a battery casing (SparkFun) that we used to house the twelve batteries (there are three battery casings):
As you can see it comes with positive and negative wires for easy access. We actually collected three battery packs and combined them together eventually attaching them to the positive and negative ends of a ribbon with a brick on the end. Here’s the picture:
You can see the three battery pack outputs coming together into the electrical tape where all the connecting happened. Be sure to put electrical tape on all the places you’ll have bare wires. It’s a good idea to encase the ribbon in electrical tape as well.
So I have to put the batteries somewhere right? So, I made a harness from some canvas that goes over my shoulders. I made a battery case where I could secure the batteries into elastic pouches, and soak sweat up with a thick covering. Here’s an image for that:
My only complaint is that the harness would sag down when I sweated a lot. There was some adjusting that had to be done, but they still sagged. I get REALLY sweaty when I wear fursuits (partly because of all my fur) so it was a concern that I might short the ribbon or the wires near the batteries. That didn’t happen, the whole thing is pretty secure.
To accomplish something like I did, it just takes a little know-how for soldering and connecting electrical parts, but not more than that. I’ve shown as many pictures as I could so you could follow along with the pictures. Sometimes I’m not as clear when I type things up.
I hope this is helpful and a starting point for you to do something similar, or to increase the battery life of other devices.
Be VERY careful with NecoMimi ears in fursuits. I put mine in a bag and heard a little pop. The servo for the right ear had broken. The servos are actually the ear parts themselves, rotating along the headband. That was the end of that ear, it didn’t work anymore and we couldn’t fix it. We took the head apart to look at it, and it’s been apart ever since. It was a great fursuit head, but its time had come.