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Compatibility of rechargable batteries

Posted: 22 May 2019, 20:05
by schmaker
Hello there,

i have replaced valve batteries with rechargable ones. Everything seems to work well except for reported battery level (even fully charged shows maximum 75%) and battery life is horrible (1 month approx.)

Do we need firmware fix maybe or anybody has good working batteries that are rechargable?

Re: Compatibility of rechargable batteries

Posted: 09 Jun 2019, 15:15
by HurdyGurdy
Trust me , even without using rechargeable batteries, battery life is abysmal. Valves report empty battery when voltage drops below 1.45v on a standard 1.5v AA, even after applying the alleged strip sent out to fix this

Re: Compatibility of rechargable batteries

Posted: 10 Jun 2019, 10:03
by mhaga
Hi,
What kind of rechargeable batteries are you using?
Normally rechargeable batteries have a slightly lower terminal voltage from the start. About 1,2 volts compared to 1,5 volt on alkaline and even higer, 1,8 volt on lithium metal.
Even if rechargeable batteries fits and have the same measures as AA, AAA and so on, they are different in the terminal voltage and can not necessarily be used.
I have read somewhere that rechargeable batteries are not recommended on the valve thermostats, but I cannot find where I read it. In my experience, the valve thermostats are very sensitive on battery voltage. Not only for the indicator but also functional. I have had a lot of trouble with the valves and that they did not close completely and the best solution I have found on this so far, is to use lithium metal type of batteries.
All problems went away and the battery indicator have reported 100% full batteries since I started using them. 16. January 2019. Almost 6 months now.
If you are struggling with issues related to batteries, I can recommend using lithium metal type of batteries. They are a little more expensive, but it made a huge difference to me and my setup.

BR
/mhaga

Re: Compatibility of rechargable batteries

Posted: 03 Aug 2019, 10:03
by schmaker
Sorry for late reply. I use ordinary rechargable Philips NiMH batteries.

I dont really want to use single-use batteries. So yo had more luck with Li-Ions, Li-Pol or something else?

I know that first battery pack from netatmo holds charge for like 6 months or so (depending on distance to relay and how often valve opens - closes), but i dont feel like using single use batteries (from economical and ecological POV).

Thanks
Roman

Re: Compatibility of rechargable batteries

Posted: 05 Aug 2019, 22:48
by mhaga
NP!
I have not tested any more, as using the lithium metal batteries took all my problems away.
As mentioned above, I replaced them in January. Still they are at 100% according to the indicator.
I understand your view, that recahargable would be better, but I have not tested any. Considering testing some Ni-Zn 1,6V rechargeables, but have to read and investigate more.
Don't want to use batteries that can start a fire or dispose gasses inside my home, so have to do some reading on Ni-Zn before I buy some.
At least they have proper voltage and I think I will try these first, if going towards rechargeable. Been looking at Ansmann AA / HR06, but they are only half the capacity of the lithium metals I'm currently using. Think I will wait and see how long the lithium metal batteries last before I do more testing.

I guess it all depends on how much time you want to spend on looking after you batteries and how often they need to be recharged. Imho, more than once a year is not good.
If I can find a good and reliable battery, that I can replace/recharge once a year, I'm happy.

BR
/mhaga

Re: Compatibility of rechargable batteries

Posted: 30 Oct 2019, 20:02
by schmaker
So, i bought NiZns and chargers. Running strong so far (changed NiMHs once already and NiZns are still at full health), will report if any problem occurs

Re: Compatibility of rechargable batteries

Posted: 04 Nov 2019, 18:51
by mhaga
Hi,
This is interesting news. Keep us updated on how this evolves.
My system is still running strong with the lithium metal batteries. Still 100% and in use since 16. January 2019.
Rechargeable batteries would be good, but I will have the old ones running until they are empty or problems occur.

Thanks for the information. It would be good to know how long the NiZns lasts on one charge cycle.

BR
/mhaga

Re: Compatibility of rechargable batteries

Posted: 26 Nov 2019, 21:29
by tomkol
I`m currently running 11 valves in our flat and also came across this topic. Eneloop & Pro show only 50% right from the start, 1.2V seem to be not enough.
Now I gave Blackube LiOn 1.5V rechargeable batteries a try, installed the first two valves 2 months ago and they work perfect and still show as "full" in the app.
Seems to be a perfect fit for those valves!

Yes they are a bit high in price, but charge very fast and easy by just plugging in a Micro-USB cable!

https://www.amazon.de/gp/product/B07J9P ... UTF8&psc=1
https://www.amazon.de/gp/product/B07D9K ... UTF8&psc=1

Re: Compatibility of rechargable batteries

Posted: 27 Nov 2019, 14:07
by Tommaso Florino
tomkol, be careful with li ion batteries. as fa as I know standard voltage for a li ion cell is 3.7 v. (as well as for Li-Po). they lower the voltage with electronics put inside the battery. this is also the reason you always see 100% in the app. also the charger regulator is inside.
lipo and li ion are very sensitive to charge discharge. they could explode both for high voltage and also for too much low voltage. in fact in R/c (where they are greatly used) there are controls to cut energy if voltage is too low. I don't want to scare anyone because I assume thise batteries where tested before being put into commerce, but they are very delicate batteries to manage

Re: Compatibility of rechargable batteries

Posted: 29 Nov 2019, 09:25
by tomkol
yeah, fully aware of that. they work really well, of course you have to take care to not short-circuit them by fault.
only downside for me is, that the electronics keep the 1.5V stable until the end and then simply turn off. So you will always see them as "full" in the app until they suddenly turn off.
They are being charged via an integrated Micro-USB port, so no normal charger possible