Checking out rechargeables for all my IOT stuff is on my list of 2021 projects. I can't immediately think of anything I have that takes a CR2450 but if so I'll report back. Many mfrs say rechargeables won't work, but I'm skeptical.
I've gone rechargable for AA and AAA batteries (I went with the Panasonic Eneloop which I'm happy with), have not pulled the trigger for anything else yet like my iOTs, but very interested in how this goes.
I think I need
- cr2450
- CR2032
- Cr123A
- CR2
The only problem I see with using rechargeable batteries is the very low capacity, especially in the coin cells. I wanted to do this for the car remote fobs, and for the battery eating Smartthing presence fobs.
A good example of this is the common CR2032 which normally has approximately 220 mAh, but in rechargeable form it is only 40 mAh. That means you are charging at least 4 times as often as you would replace the cell.
Even the CR123 and CR2 suffer this same fate. AA and AAA are much better at this, they have almost as much capacity in rechargeable form as they do as alkalines.
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It happens. I use rechargables for everything. I've got a 26 slot charger with 12 AAs, 12 AAAs and 2 9v always at the ready, and a box of extras that only get used around the holidays (candles, animated crap, etc.)
They work fine in everything (remotes, keyboards, candles, flashlights, etc.), except for one stinking Christmas decoration. It's a snow globe thing that looks like a church with a little motor and some led lights. It absolutely refuses to work with rechargables, but works fine with regular AA's.
I think the voltage is slightly lower than throw-away batteries. Some things are probably sensitive to this.
I have run this experiment multiple times. I really like the CR2 & CR123 rechargeables. I change them on a 6-10 month schedule depending on area activity. I like the soshine CR2, and the best I've found is the EBL CR2 & CR123. The higher voltage has never damaged any of my sensors. You'll need a special LiPO4 charger, I love my miboxer 4 & miboxer 8, chargers
Please do not get the LIR2450 or LIR2477, what a total waste of money. I could not find a reputable brand so bought generic and man are they junk. Don't even last a month in samsung motion sensors. Don't even know if there exists a reputable source for rechargeable in this size, likely do to very small demand
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I like orbtronic batteries for 123 and CR2 
and other 18650 and such too !
Yes, had a look at those. Seems rather expensive. The soshine ones I got were cheap, but now appear to be out of stock almost everywhere, and with lithium shipping costs out of China skyrocketing, I doubt I'll be able to replace in 5 years or so when mine lose capacity.
the orbtronic one are worth it i have 6-8 cr123 (the 700mha the 850 will be to big) and they work awesome 
going on 2-4 years with a couple of these
found these on fleabay, ships from commiefornia, 4 batteries CR2 for 7.99 shipped.
Does anyone have experience with rechargeable CR123A batteries?
I have several devices that take CR123As. One particular device says specifically not to use rechargeables: the Aeotec Multisensor 6 (in the user guide). I suspect that's because of the voltage difference: most of the rechargeables are 3.7V, and not 3.0V.
I found these EBL rechargeable CR123A batteries that are 3.0V. Has anyone tried them? I wonder if they'd work.
I can‘t speak for those batteries but I use these on my multisensor 6.
They say they are 3.7 volts. I can't remember how long they last.
I can't find this on amazon.com though, but it looks like searching for Arlo rechargeable will give you 3.7 volt batteries.
Interesting - because Aeotec's manual says explicitly:
Do not use rechargable CR123A batteries.
I bought a package of the EBL 3V rechargeables, and I'll see how they work.
I‘ve never been on to read manuals.
I have both the CR2 & CR123 from EBL. I have many advanced chargers from a longstanding flashlight addiction. Both sizes of the EBL's test at or above their rated mAh capacity and work very well in all my sensors. The sensors don't seem to mind the extra 0.5 volts. Only oddity is my Inovelli 4in1 sensor reports 0% battery, when the battery is above 4 volts.
Also the CR2's are about 1mm longer, and the horrible design of the samsung flood sensor will have you fighting to get the CR2 out, without shredding the wrapper to bits. I'm going to take a dremel to that sensor and add the 1mm clearance I need.
I also have shockli CR123's and Soshine CR2's. Those are both okay, but not as good as the EBL's. The prices of all of these have skyrocketed, and the shipping is way up.
As far as the EBL's with built in USB port, I'd imagine the space taken up by the built in charging circuit, would reduce the capacity, unless they're using some newer lithium tech
I bought a bunch of these ELB CR2 batteries for Iris contact and motion sensors. I just replace one in an Iris V3 contact sensor and the temp of the sensor went to -469.23 degrees, which of course messes up my HVAC automations. I tried a different EBL CR2 battery same result. I switch back to a non rechargeable CR2 and the temp went back to reading normal.
Anyone else using the EBL CR2 rechargeables seeing this also?
So far I'm only using them in Iris v2 motion and contact sensors, and they work fine. I have just 3 of the v3 motions. I will try a RCR2 in one of those to see if this happens.
Update: oh, the v3 motions take CR123A batteries. I can't test this.
AH HA, that is so weird. Thanks for figuring this out. The only thing I can say is the EBL are 4.2volt, the standard CR2 ar 3.2 volt at tops. My inovelli 4in1 sensor goes nuts with a fully charged EBL at 4.2 volts and reports 0% battery but works. I have 2 V3 iris sensors reporting temperature fine with the EBL's, although the batteries maybe getting on the lower side for voltage, as I haven't charged in over 6 months. Maybe try not fully charging the ones you depend on for temperature?
How could a voltage change affect the temperature circuit? Could it be that sensitive, that a small over voltage would affect the temperature?
Unfortuantely for me I use the temperature reading of 38 different sensors all using CR2's to provide an average temperature for my HVAC automation. I bought 40 of these rechargeables to replace having to buy new ones every year. So not much options for me. I will leave one in to see when it discharges if the temperature begins reading properly.
