[Released] Rrechargeable batteries in Smart Radiator Thermostats VA02 hardware revision



  • Dave21w
    edited January 24

    Read the info, it says if you take the head off as when changing batteries it will say V01 or V02 somewhere, V02 means Ni-Mh batteries are supported

  • Dave21w
    edited January 24

    Maybe this explains why some people say they are using the Panasonic batteries and don’t have any issues,

    Call me cynical but I have to wonder if this was kept quiet till all the V01 version TRV heads had been sold and were out of warranty!

  • GrayDav4276
    GrayDav4276 ✭✭✭
    edited January 24

    Hi all,


    Tado really ' sneaked ' that information in.......why don't they " UPDATE " everyone when they

    ' appear ' to have made a significant change.

  • I posted this previously but it got deleted, i'll try again,

    buyabattery.co.uk have the Panasonic Eneloop Pro cells which are 2500mAh, a pack of 8 is only £26.50 which I think is a good price.

  • Hi @Dave21w,
    In your last post the batteries you mention are different to the ones in the Tado Info, are these still compatible...??🤔
  • They are just a more expensive version as they have a higher capacity so their run time will be longer, have a look here for some technical info.

    The reason Tado specify these is because when a valve isn't operating (moving to open or close) the standby current of the unit is so low that an oridnary Ni-Mh cell would just loose it's charge before the valve actually had chance to flatten it.

    What I mean by this is (this is an example and not anywhere near the correct values) lets say the valve in standby uses 1mA and an oridnary Ni-Mh cell would have a self discharge rate equivalent to 3mA being drawn constantly so the cell would discharge quicker on it's own. As the valves spend most of thier time in standby you need a cell that has a good standby time. The only disadvantage is the sharp end point curve, just means when you get a low battery notification you need to change pretty much straight away.

    Hope this helps.

  • Thanks @Dave21w,
    Really helpful.... Cheers
  • cbd20
    cbd20 ✭✭
    edited January 29
    Wow, can't believe they've snuck out this update to their web guide.

    It was something that made me hesitate in buying them initially, although I did go ahead in the end.

    Time to check what version I've got installed.
  • Glad to see the positive update on this, of the 10 TRV's I have I believe that 8 are version 2, those with rechargeable batteries in no longer say they need replacing. The 2 older ones (version 1) say they do need replacing. At the end of this heating season I will swap some around so that the 2 version 1's that I have are in little used rooms.

    For Info V1's I have show firmware as 54.9 and V2 show as 75.2 (in the app)

  • samd
    samd ✭✭✭

    @Gav That's very useful - no need to remove to ascertain which version - thanks

  • +1 for a rechargeable battery update

  • As some of you already noticed:

    We have released support for Eneloop 1900 NiMh rechargeable batteries for the VA02 hardware revision of the Smart Radiator Thermostats.

    - Why only Eneloop 1900 ?

    Because other rechargeable batteries might be too thick to fit into the battery compartiment because they are thicker than Alkaline batteries. We have tested Eneloop 1900 batteries and they fit the device.

    If you already own different NiMh rechargeable batteries and they fit fine, there should be no problem with using those NiMh batteries.

    - Why only the VA02 hardware revision?

    Alkaline batteries have a voltage of 1.5V, NiMh rechargeable batteries have a voltage of 1.2V

    To allow the accurate detection of depleted batteries we have implemented a whole new algorithm that no longer looks at idle voltage but only looks at voltage under load (when powering the coils of the motor). That way, the different in idle voltage no longer is relevant for the Smart Radiator Thermostat.

    Unfortunately, this detection method was not implementable in the VA01 hardware revision because it uses different hardware components that do not allow us to look at this voltage under load.

    - How can I check if I have VA02 or VA01 Smart Radiator Thermostats?

    The easiest way is to check the current firmware version. If the firmware version is 70.x or higher. If this is the case, you have the VA02 hardware revision and you can start using Eneloop 1900 NiMh rechargeable batteries.

    The next way to check is to look at the sticker on the inside of the device, it will state either VA01 or VA02 under "Modell".

    - I have the VA01 hardware revision, what should I do?

    In that case, the device will only support Alkaline LR06 batteries.

    You can also find this information in the updated Help Center article:


  • @Jurian out of interest, as it now only checks the voltage under load, does this mean that if the batteries are to run low during the summer season that we won't get a low battery warning until the first actuation of the heating season?

    Or do the valves periodically actuate throughout the summer months anyway? If not, then perhaps something to consider as this periodic actuation might be useful and serve two purposes: checking battery status, (Appreciating of course that every valve actuation will deplete the battery slightly!) but it would have the added bonus of ensuring valve pins don't seize in the summer months.
  • Jurian
    Jurian | Admin
    edited February 10

    @cbd20 Good Question! The firmware will periodically energise the coils in the motor (this does not make noise or move the pin). This allows for accurate voltage under load measurements even in summer.

  • @Jurian Thank you for the clarification and additional details that you have provided it's very appreciated.

    To save others the trouble I can confirm that Ikea LADDA AA rechargeable batteries (which I believe are repackaged Eneloop Pro) do not fit as they are too fat.

  • Jurian
    Jurian | Admin
    edited February 10

    @Gav Thanks for that feedback.

    Most NiMh batteries seem to be too fat.

    One Enegizer model, and a specific Amazon Basics might fit, but we only recommend officially the Eneloop 1900's for consistancy and quality.

    See this very interesting video from ProjectFarm:


  • Thanks again @Jurian , I've watched most of the ProjectFarm videos, I've got some Amazon Basics ones which fit but they have changed where they source those from now so cannot get anymore. I've also got plenty of standard eneloops in several things (non-Tado) so just need to swap those with the Ikea ones and I should have enough. Really pleased Tado have responded to this request, luckily only 2 of my SRV's are v1.

  • Does anyone know if both of these eneloop 1900’s work?

    Panasonic eneloop, Ready to Use Ni-MH Battery AA Pack of 8, min.1900 mAh, 2100 Charging Cycles Low Self Discharge https://www.amazon.co.uk/dp/B06Y6DGM86/ref=cm_sw_r_cp_api_fabc_B9XDY979YT636SER4N6M

    Panasonic eneloop BK-3MCCE/8BE Nickel Metal Hydride AA Batteries, Classic AA 8-Pack https://www.amazon.co.uk/dp/B00JZBX8DQ/ref=cm_sw_r_cp_api_fabc_6DKR3D1W6TV7TAX97BGQ
  • I’ve just tried the Lithium ion batteries by Hixon. These are from Amazon.
    These rechargeable batteries are 1.5v. Seem to be working perfectly.
    The size is like any standard alkaline battery.
    Hopefully these are the answer 👍
  • @chriso1900 We have done testing with those USB rechargable lithium 1.5V batteries.

    They work fine, but you will not get a notification in time when they are about to be empty.

    Because they have a stabilised voltage, the tado device won't know when the battery is nearing the empty state.

    Just be careful before you go on vacation in winter.

  • Any idea if Tado will release a similar support for smart thermostats?

    I have used bog-standard Amazon rechargeable batteries in my thermostats for a good while now, and they work fine. Except you usually get a permanent false low battery warning in the app, which is a bit annoying.

    Would be great if the same firmware tweak could be applied to thermostats.

  • Great to see the option for rechargeable batteries. I think low discharge models are going to be essential as standard rechargeables can go flat within a month or so when only used lightly.

    I did wonder why the AA's (i used some older 7dayshop ones) were a little tight to get in. You would think an AA battery would be sized the same, but you are clearly right as I've had problems in the past with rechargeables in various items being too chunky.

    Really happy this has been done as it's not nice to see over 20 batteries getting slung every 9 months.

  • This is a fantastic thing to happen and you should shout it out loud as this will benefit Tado users. May also help sell some more TRVs

    The downside for me is that I have 7 of the old version.

    Good work though getting this through.

  • Excellent news. Eneloop batteries are the best. Never ever go flat in the box, unlike lots of other non-long-life rechargeable batteries. I've been using them for the past 10 years and have about 30 of them in both the AA and AAA sizes. Nice to know Tado also like them. I put eneloops in all my Tado TRVs when I got them about 6 months ago, but didn't know until now that Tado also recommend them.

    It's best to get a decent charger for eneloops, not some cheap £15 model. I paid about £40 for my charger, the Maha (or PowerEx) PowerLine-9000. It's not sold any more, but there are similar models out there. It tells me the capacity of my batteries when I recharge them, and it can also refresh and bring dead batteries back to life. Rescued 10 of my eneloops when I got them back dead after a friend borrowed and abused them.

  • I always use rechargeable batteries and have never found they are less effective than non-rechargeable. They have lasted approx 9months between charges and do not cause any faults.
  • There are refurbished radiator valves on sale, but no indication of which version they are.
  • Jurian
    Jurian | Admin

    @scrat All of our refurbished products in our webshop will be VA02.

    Also all non-refurbished products are VA02 (if you buy from www.tado.com)

  • This is really good news! (apart from the fact I just ordered 8 x AA batteries today in preparation for more swaps).

    I'll start replacing the standard AA with rechargeable as they die.

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