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

tado EDIT 10.02.2021: 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:

Original Post:
While the smart radiator thermostats do seem to work with rechargeable batteries, you can never get rid of the low battery notifications and cannot tell when the batteries are about to die.


  • Hey_youth
    Yes, I have encountered this previously & changed back to alkaline. I presume the ‘low battery’ indication is monitoring voltage & rechargeables are 1.2v as opposed to 1.5v.

    I think ‘normal’ battery charge falls away slower down to 1.0v than rechargeables.

    Perhaps just recalibrate to an absolute ‘LOW’ of 1.0v, with also a ‘MED’ above that.
  • Pyro

    Please make rechargeable batteries usable with Tado. It's amazing it's not already implemented.

  • ns9rt

    Completely crazy that an energy efficiency product doesnt allow use of rechargeable batteries.

  • Radu
    Fujitsu/Panasonic Eneloop Pro work for me and I rarely get the low battery warning.
  • JohnnyM
    Great to hear that Panasonic Eneloop Pro batteries work for you. I use them as well but ALWAYS get the low battery warning. Clearly not a simple fix.
    I just ignore the warning and charge them up
    before turning the heating back on after summer. The majority of them last through to turning the heat off again the following year.
    However, this seems against the professed values of Tado and I agree that it is ridiculous that this issue has still not been addressed.
  • Cheeman
    I agree support for rechargeable batteries please
  • ArVee
    Enabling the use of rechargeable batteries would be a big plus!
  • cor

    Given the level of discussion, both here and other places, I am staggered Tado have not yet implemented a fix so that we can use rechargable batteries without having to have the 'low battery' notification constantly on.

    At the very least, some proper feedback - indicating either an estimated implementation date or a technical explanation of why it can't be implemented, should be provided.

    Come on Tado - show some customer consideration!!

  • Firdi
    I finally gave up on 1.2v rechargeables and though substantially more expensive, picked up some AA rechargeable 1.5v lithium batteries (usb charge port).

    Solved the constant false positive low batt warnings. Downside.... can't prove it yet (as not had too long) but suspect the cliff edge discharge profile means I get little to no advance warning before too low to drive valve.
  • Please providecsupport for rechargeable batteries
  • Simon_M
    Yes, I have 4 thermostats, and 4 TRV'S, such a waste to use disposable batteries in all these devices. I have used rechargeable with mixed results, they are working in the thermostats but with the battery warning (something I can live with). But didn't work for me in the TRVs, maybe I need to try a different brand (I'm using cheap Amazon Basics rechargeables).

    This is an important green issue for Tado to resolve, very poor it has taken so long.
  • kenneth121
    It's not something they can "fix" it's a consequence of the chemistry of rechargeable batteries, most will stop charging at 1.2v so they only way round it, that I can see, is tado code a slider into the device section that lets you turn off low battery warnings. They could still message you when the device goes offline and you would know it's dead but it may not work well in the final days / week death throws as the output from the batteries wouldn't have the juice to operate the internal mechanism and effectively close the actual rad valve.
  • One of the things Tado profiles itself with is that it is better for the environment because of the energy savings. Using a set of batteries every half year for each smart thermostat contradicts this. The curve of ni-mh batteries is different than conventional batteries, but they do work excellent. I really would like an option for each smart thermostat indicating the type of batteries you’ve put in. This can adjust the battery low warning. I will accept that the device goed more suddenly offline, due to the discharge curve.
  • Gregge

    I'm looking at adding about 10 TRVs. The only reason why I'm hesitating is due to the rechargeable batteries issue.

  • ErwinM
    edited October 2020
    Dear TADO, the fact that rechargeable batteries cannot be use at this point in time makes the system too expensive for my wallet and my planet. I highly suggest this be looked at because as it stands it keeps me from expanding the system in my home and it prevents me from recommending the system wholeheartedly to friends, neighbors and family. Which is a shame, as I am very much a fan.
  • Jurr_on

    Come on Tado , start reducing waste and be a bit more part of the circulair economy! Within a couple of years the non rechargeable LR6 Alkaline battery is not the standard anymore. Do you know that companies like IKEA stop selling these type of batteries? It makes no sense that Tado isn't supporting rechargeable batteries yet. Please change this soon. https://newsroom.inter.ikea.com/news/ikea-to-remove-non-rechargeable-alkaline-batteries-by-2021/s/bd0e6e55-ccc4-46d6-8b37-bb1f9dfa24ff

  • mr_reamer
    Come on Tado... FFS lol
  • kefa

    Please can you prioritise this ASAP. it feels totally wrong with everything that is going wrong with the planet at the moment to be discarding so many batteries every year. I bet Tado can calculate the number of tonnes of batteries being discarded each year across all their users - makes me feel ashamed. Perhaps they could be transparent and at least publish this figure so we can see the size of the problem. This should be key objective for the company (along with reducing boiler energy consumption).

    I have several zones and this is the key issue that is stopping adding more radiator thermostats. What about an option to set the battery type and send low battery reminders based on a conservative timescale (say 4 months) rather than measuring voltage (if the current devices cannot accurately determine discharge of NiMH).

    appreciate your help on this.

  • Flirkx

    Come on tado, it must be possible to make a battery sensitive fix or a digital switch in your program to adapt to (at least quality brands, recyko, eneloop) rechargeable batteries. We can’t keep throwing away alkalines!

    Thank you

  • Jan69

    Please fix this. It should be an easy software/firmware update. im not going to buy new batteries for 10 devices every 6 months. thanks

  • UKenGB

    What is the actual minimum voltage before a TRV stops functioning? How long does a rechargeable work until it reaches that level?

    If it’s a really short time, then rechargeables aren’t really a practical solution without a hardware change, but if it’s a sufficiently long time, then the only reason not to use them is the low battery warning and that would just be a software fix.

    I rather suspect it’s the latter so tado need to do something about that. As has been pointed out, this system is supposed to be better for the environment, yet chews up batteries at a prodigious rate. I have about 15 of their TRVs and battery costs WAY exceed any possible savings their system is supposed to provide and that they keep telling me it does.

    Speaking of which, how are these savings measured? Compared to what? It’s obviously just marketing BS as they have NO possible idea of what the energy consumption would be without tado, so they CANNOT POSSIBLY calculate any changes, for better or worse, due to the use of the tado system.

  • samd
    samd ✭✭✭

    @UKenGB Interesting comparison for me. 8 tado TRV on original batteries just over 1 year and still showing OK!

  • Gav

    @UKenGB I'm using good quality rechargeable batteries in mine, Eneloop Pro or equivalent and they easily last a UK winter/heating (~6-7 months) season. I just charge them all in the summer. I have 9 TRV's (6 zones), rechargeable AAA in two thermostats (one main one and the other just as temperature sensor to give smoother temperatures in the lounge) also are fine, these don't even show as low.

    Also be aware that Ikea LADDA AA batteries (which are highly likely to be rebranded Eneloop Pro) have a cheaper casing which makes them slightly too fat to work properly in the TRV's. They are also a pig to get out again so best avoided.

  • JESC

    +1 for rechargeables.

  • Luca77

    the main purpose of having tado is to reduce emissions and pollution. show how much you care for the planet and add compatibility with rechargeable batteries.....please.

  • Mine doesnt even detect low alkaline batteries. Just had the boiler on all night as a TCV called for heat but wasnt opening t0 achieve it.

  • AndyMarden
    edited November 2020
    I just got the whole tado shebang and now I see this issue. What's great is that tado staff have commented on a threaf to say "Please raise the issue over there" and then on that thread, there is not one comment from Tado staff to say they even recognise the issue...
  • Skribble

    One more vote to rechargeable batteries.