Add a battery to an old-school Bose SoundDock?

March 2, 2019 2:41 PM

I have an old-school Bose SoundDock that I've resuscitated by adding a Bluetooth adapter. Is there any way, though, to make the SoundDock (semi-)portable by adding some kind of battery pack to it?

The power cable is a funky four-pronged dealie (pics here), and it connects to a pretty traditional-looking power brick that plugs into the wall. This post appears to have some more details about the connector. Is there any way to plug any sort of battery into that instead? Thanks for your help!

posted by Conrad Cornelius o'Donald o'Dell to Technology (5 answers total)

Best answer: Not that's really practical. You can get battery packs with built in AC inverters that you could just plug the brick into but they cost more than the speaker is worth and tend to be fairly bulky. You're losing efficiency as well, going from DC to AC to DC. With enough transformers and electronics, you could make something pure DC but it's not going to be easy, cheap, portable, or easy to recharge.

I'd just take the money and buy something new for portable use and leave this someplace where it's useful plugged into the wall. The new generation of portable speakers are surprisingly good, small, and cheap.
posted by Candleman at 3:30 PM on March 2, 2019 [3 favorites]

If you could find two 18 volt batteries like for a cordless drill (or one 36 volt one), you could hack something together that would work.

You would need to get another connector like the one on your power brick and make a case for your new battery pack.

I think it would be a lot of work to do this without it looking like a mess though.
posted by ArgentCorvid at 5:08 PM on March 2, 2019 [2 favorites]

I think Candleman has got the wrong end of the stick but ArgentCorvid is on the right track.

You essentially need a 36v supply with a centre tap. 36v is a convenient voltage if you are dealing with lithium batteries, not so convenient otherwise. A hacked up double battery charger as the battery dock, the appropriate power tool batteries and another charger to charge them up again could work well and look reasonably elegant, but you aren't going to get there without a bit of electronics knowledge. Probably not cheap either.
posted by deadwax at 7:35 PM on March 2, 2019 [1 favorite]

Response by poster: Thanks, folks. I was hoping there was some sort of off-the-shelf option, but clearly not the case! Candleman's advice to just buy a new cheap portable speaker is what I decided to follow.
posted by Conrad Cornelius o'Donald o'Dell at 10:17 PM on March 2, 2019 [1 favorite]

Deadwax' suggestion is roughly how I would do it, but instead of two batteries for a cordless power tool I'd use two battery holders for 4 or 5 18650 Li-Ion cells (less lumpy/sticking out), an 18650 charger (cell holding capacity depending on budget and desire to charge as much of them in one batch) and a number of 18650 cells. I've seen battery holders (and chargers) for up to 4 cells; 5 would probably need holders for 2 and 3 cells in series. 4 cells would mean running at around 14V instead of 18V, but that's probably inconsequential. I'd expect it wouldn't be very difficult to mount those battery holders to the back of the SoundDock
posted by Stoneshop at 6:04 AM on March 3, 2019