Those who use headphones with Roku remote know how fast it eats up batteries. I hate buying alkaline batteries since they all end up in landfills. For a while I used Ni-MH rechargeable cells, but those have lower voltage and high self discharge rate, so you end up constantly charging and swapping them. Since I'm an electrical engineer and work with lithium batteries for a living, I decided to try and convert my Roku remotes to lithium rechargeable cells. I was surprised that lithium cells were available in AA size, so no need to hack the remote and make it look like Frankenstein monster. I also realized that LiFePO4 chemistry was a better fit than LiNiMnCo, since voltage profile of LiFePO4 is 2.5V to 3.65V , which is close to 2 Alkaline cells connected in series. Maybe LiNiMnCo cells would work also, but there is greater risk of damaging the cells on the low end due to over-discharge and damaging remote's voltage regulator on the high end due to 4.2V full charge voltage. Also, LiFePO4 cells are much safer and have much longer cycle life. So, I picked up 500mAh 3.2V cells 14500 size ( same as AA cells ) on Ebay along with compatible charger. Then I opened up my Roku remote, confirmed that cells are connected in series, which means voltage regulator is expecting nominal 3V. Voltage regulators always have design headroom, so feeding 3.65V maximum voltage from LiFePO4 cells should not be much of a problem. I converted series connection between 2 cells into parallel connection by cutting copper traces and soldering jumper wires, popped freshly charged lithium cells and ......... everything just worked perfectly. I use headphones with my Roku all the time and now my batteries last for 1-2 weeks between charges. I have 2 sets of cells, so one set is always charged and waiting to be swapped. I did this for all 3 Roku remotes in my home a few months ago and never had to buy alkaline batteries again.
I wonder if people would be interested in a service to convert their remotes to lithium cells? Remote would have to be mailed in for rework, with 2-3 days turnaround. I could also supply cells and chargers as kit, so people don't have to search the Ebay and mistakenly buy wrong cells, etc. I guess I could buy remotes and convert them, but it would cost more to buy an extra remote instead of sending in the existing one for rework. Any feedback? Conversion would cost $25-$30, plus USPS shipping, plus cost of lithium cells and a charger. It would pay for itself in a few months of not buying alkaline cells.
While searching last night as to whether I can use rechargeable batteries for Roku 3 remote with earphones, I came upon a perfectly adequate workaround. That is the Roku app on my andriod phone.
I just plug my phone into the charger and use the virtual remote from my phone. The sound seemed better through my phone too. The nice thing about this arrangement aside from not eating up batteries every two days is that I can still change channels and such with the real remote, even though I don't have the headphones connected to it. It's still easier to channel surf with the actual remote than my phone. But, I have not tried the voice navigation yet though. Even if that works well though, I probably won't use it in the middle of the night which is why I use the headphones to begin with; to avoid waking my wife when I happen to be awake and wanting to watch tv. So, speaking to the phone could also wake her. But I will try it just to see if I like it more for daytime roku control.
I found this string while looking for info on using rechargeable batteries. I agree that the Roku app has relieved me of the issue for the greatest part. I use headphones at night also and using a phone with an app has created a lot less dependence on using AA batteries in my Ultra remote. We have 4 Rokus and the only one with headphone jack is an Ultra, which is the only one of ours eating batteries.
I tried using the Roku app on my Android cell phone to control the Roku Ultra and connecting the headphones to the cell phone jack, and it worked like a charm for using headphones without draining the Roku remote's batteries. The cell phone can be plugged into a charger to restore it's power unlike the Roku remote. I do wonder why Roku engineered the remote without a plug for an external power supply to use when using headphones; it seems like using the the headphones are the thing that drain the remote's AA batteries. On the other hand, using the Roku app on a cell phone that does not have a headphone jack would not help.
I hate to be the one to squash this, but you will get more energy out of 2 AA batteries than 2 LiFePO4 14500 batteries. Other technologies, like Li-ion, are far more energy dense than LiFePO4.
Here's the math for it:
Energizer AA alkaline batteries have 1.5 nominal volts and 3,000 mAh.
14500 LiFePO4 batteries are 3.2 nominal volts and 500 mAh.
2 Energizer alkaline AA in series is 3 nominal volts and 3,000 mAh.
2 LiFePO4 14500 in parallel is 3.2 nominal volts and 1000 mAh.
The Alkaline batteries will have 9 watt hours.
The LiFePO4 batteries will have 3.2 watt hours.
The alkaline batteries have almost 3 times more energy than the LiFePO4 batteries. The cheapest Li-ion would, by far, outlast the best alkaline cells.