Forum Discussion

electric123's avatar
electric123
Visitor
8 years ago

Converting Roku remotes to lithium rechargeable batteries

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.

remotes
  • Slam2456's avatar
    Slam2456
    Visitor
    6 years ago
    My brother is an electrical engineer and there's no way he could have invented this hack.  Yet he's successful, having found a niche by working for utility companies.  I can't figure out his success.  Anyway, what are people supposed to do for the week or 2 that they've sent you their remote?   And even with this hack, you still have to change batteries every 1-2 weeks?  I wish Roku would make a remote that just took C cells - or just plug into the wall!    Also, do you find the Roku remotes problematic generally, with the buttons not working consistently?  My volume control buttons sometimes function as a pause button, which is aggravating.      Last night the remote just stopped working, with no battery indicator warning, even though I just changed the batteries 2 days before with 2 rechargeable batteries (830 mAh) and now again but with 700.  I have the receipts on the counter, ready to return, but Chromecast doesn't have a remote control and Apple TV costs $150, and Amazon Fire TV won't support Youtube TV until late 2019.
  • Chicken's avatar
    Chicken
    Roku Guru
    6 years ago
    Install a charge port on the remote and you have a big winner, IMO.
  • Slam2456's avatar
    Slam2456
    Visitor
    6 years ago
     Great!  Please send me detailed directions, and a video of you doing the same thing to your remote.  Maybe one of the boys from NASA can come over to help. Smiley LOL
    • jeff_net's avatar
      jeff_net
      Roku Guru
      6 years ago
      I admire your hack. I just think it's pathetic that Roku released a remote that eats batteries in a matter of days. Obviously their remote should come with rechargeable batteries to begin with.
      • jeff_net's avatar
        jeff_net
        Roku Guru
        6 years ago

        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.

         

  • phirephoto's avatar
    phirephoto
    Newbie
    6 years ago

    Hate to bump an old thread, but did you ever get this done? Debating buying a new Roku, and would love this....

  • NightFire's avatar
    NightFire
    Newbie
    4 years ago

    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.

    • andres777's avatar
      andres777
      Reel Rookie
      3 years ago

      you forgot to mention how many times you can reuse rechargeable batteries vs  how many alkaline batteries go into the landfills vs equivalent rechargeable batteries... and the cost benefit of recharging batteries!

  • andres777's avatar
    andres777
    Reel Rookie
    3 years ago

    Roku has now rechargeable remotes, but some people are having issues with short battery life and not being able to recharge after 1 yr.
    This hack is perfect, because replacing batteries makes more sense. I wonder if buying LiFEPO4 batteries with higher mAh (600-800) would extend the charge life...
    And yes, button functions sometimes behave erratic, I guess it's not perfect yet, after all these years of use and research... 😞