Beyerdynamic Blue Byrd (1st generation) battery replacement

I’ve had a pair of Beyerdynamic Blue Byrd 1st generation bluetooth earbud headphones since June 2020. They are great Bluetooth headphones but were recalled just after I bought them. Somebody got too sweaty and managed to somehow burn themselves on the headphone wire. Given that no replacement was being offered I refused to send mine back in the recall. I don’t exercise with mine so I figured I’d be safe enough and I have been.

Warning: I’d like to take the opportunity to mention how bad Beyerdynamic customer support is: absolutely atrocious. Everybody I dealt with over the phone were really aggressive.

The headphones have a companion app that you can do a hearing test with, and you can supplement that one with a second test through the Mimi hearing test app. The results can be used to personalised the sound that is produced, counteracting any hearing loss you have. For me, it seems to amplifies sound in the frequency range of my age-related hearing loss and tinnitus so that I can hear sounds I can’t hear so clearly using normal headphones. It works well and the sound is really great. A short while after the recall official support for upgrading the firmware was pulled from the app, but everything else continues to work as well as I need it to.


After three years the expected battery life was down from around 6 hours to perhaps 2 or 3 hours at best. To give you an idea of what an inconvenience this is: I’d have to go into a movie with a full charge or they’d run out part way through. I looked around for a replacement set but they’re hard to come by and I don’t like the design of the 2nd generation model so I decided to see if I could change the batteries myself. I watched some YouTube videos and it seemed doable!

I couldn’t find any direct replacements, the 3.7V VDL 53mAh 410920 lithium-ion seem unobtainable in 2023 and I needed two of them. I eventually settled on two 3.7V 80mAh 401119 lithium-polymer batteries, of no particular brand, but from a reputable eBay seller. They are pretty much identical sizes — roughly 2cm x 1cm x 0.4cm — and are a straight swap. The new batteries have a higher power rating so I’m hoping to get longer usage between charges: we’ll see.

Let’s do this!

The battery cover compartments separate by pulling apart — carefully — perpendicular to the seam (so, each half directly away from each other and the line of the wire). One battery, I think the furthest from the remote, has two wires: ground and positive. The other battery, I think closest to the remote, has three wires: ground, positive and negative. Just desolder the existing batteries and solder the new batteries in their place.

Warning: the remote itself doesn’t need to be opened, as it contains only a small circuit board with surface mounted buttons, the USB-C charging socket, and related bluetooth electronics. It opens with a similar process to the battery covers, but I found that it is more easily damaged (and I did damage mine) so I would recommend leaving well enough alone!

All in all replacing the batteries was pretty straight forward if you have the right tools, I recommend at least a magnifier or preferably microscope screen, and a good hot soldering iron. My friend Dave had all the gear which made the job easy. So, thanks to him!

Initial usage with the new batteries is encouraging. In a week or two I’ll edit this blog post with the sort of usage time I’m getting.

Here’s a little bit of video showing me unsoldering one of the original batteries. Everything is tiny!

Comments: @gingerbeardman