Help: Speaker removal for Li battery upgrade?

[Dirtbagleader]

So I want to upgrade my Obsidian v3 saber to an 18650 rechargeable lithium battery, but I can't for the life of me figure out how to separate the speaker from the 4xAAA battery holder.  Before I break something, anyone know how in the heck those two pieces are held together? Thanks!

[firehand10k]

Obsidian V3 uses 2 lithium ion 14500 cells. Obsidian lite uses 4 AAA cells. Both speakers are just snapped into the holder. The 2 cell holders leave 2 small holes exposed through which a small tool can be used to carefully push the speaker out. If you plan to use the speaker again be very careful to push on one of the solid parts of it. I think the 4 AAA holder covers those so not sure about that one.
None of the Obsidian cards can run on a single 18650 cell, so are you changing the sound card too or cramming two 18650s in there?

[Dirtbagleader]

I was going to try to stuff 2 in there, but out of curiosity why won't it work on just 1? You don't run the 2 in series, do you? >7V seems like a lot for that little thing. . .

[firehand10k]

Yes they do go in series. Obsidian boards  can sometimes make sound with less but they are designed for 6 for lite or 7.4 for premium sound.

[Dirtbagleader]

Ok, so I'm going to try running my Obsidian Lite board with just one 18650 and see how it goes; according to the specs it *should* work just fine:
http://rsxengineering.com/saber_resources/ObsidianLite_Datasheet.pdf
Seems the board is designed for a 3.5-5.5 VDC input voltage, with 4x 1.2V AAAs being the 'standard' configuration.  Seeing as partially discharged AAAs and a fully charged 18650 would both be about 4.0V, I don't see any reason why this wouldn't work. Ok the blade might be a touch dimmer at the slightly lower voltage, but since the lithium cells maintain their voltage better during draw-down, I think even this will end up being a wash.  Will check what LED resistors are currently in there; not entirely sure for my cyan setup.

[Dirtbagleader]

Ha, just tested it with the 3.7V lithium battery from my GoPro and it worked great! As I suspected, the 4xAAAs were at 5.2V RESTING voltage, but as soon as I turned the saber on under load they dropped more than a volt to about 4.0V.  The GoPro battery on the other hand, had a resting voltage of 3.95V and only dropped 0.05 down to 3.90V under load! So in conclusion, it seems a 3.7V lithium works fine for an Obsidian v3 Lite board!  Now if I could just figure out how to get the dumb speaker separated, I should be in 18650 business!!!

[Dirtbagleader]

Got it! Apparently you can pop the speaker itself out (I used an exacto knife at the edge, and then underneath the speaker are two screws that hold the speaker 'mount' to the battery holder. Replaced holder with a single 18650 holder and re-attached the speaker mount to it (just with one screw), and it works great!

https://photos.app.goo.gl/JN3KCTYNM6KMFnJV9
Hopefully that pic works?

[firehand10k]

Interesting  to hear about.  Let us know how th web run time is on it.

[Dirtbagleader]

Yep, will do, haven't really tested that yet, but I'm expecting about a 2-fold increase in run time (900 vs. 3000ish mAh after all!) but of course that will depend on how long the 18650 can maintain high enough voltage to keep the Obsidian alive.  Will report back once I've used it for a bit!
Oh, and FYI, this really should work on a non-lite Obsidian v3 or v4 also, as it has the same lower input voltage requirement of only 3.5V:
http://rsxengineering.com/saber_resources/ObsidianUSB_Datasheet.pdf
Will NOT work with Emerald or Diamond cards though, as they require a 5V min, so you'd need 2 in series for those no matter what.

[Dirtbagleader]

So far seems GREAT! I let my kids play with it a bit and they'd usually get maybe 3 run sessions out of it with the old nicds, now we've already had it out 5 or 6 times and still going strong, some I'm confident in a least a 2-fold improvement in run-time!

[Cyclops942]

So far seems GREAT! I let my kids play with it a bit and they'd usually get maybe 3 run sessions out of it with the old nicds, now we've already had it out 5 or 6 times and still going strong, some I'm confident in a least a 2-fold improvement in run-time!

Do please keep us informed... this sounds like an upgrade I might actually be able to tackle once my sabers’ warranties expire.