Can I replace cr2032 powered devices with AAA or li ion?

[NVZN]

So I have a tuya smart key finder that using Bluetooth technologies, and they claim it can last up 6 month 1 battery, but when I use it, only lasted 1.5 months and it self shutdown.

I'm fed up changing 2032 cells, now I got a thinking.. Can I instead keep using 2032,i wired this device to a single lithium battery (18650 or 14500).

But I'm afraid damaging the circuit, I heard 2032 is 3.2V max, meanwhile li ion has max voltage 4.2V.

Probably second alternatives is putting 3 AAA rechargeable energizer battery it would result 3.6V... What u guys think? I don't mind it getting a bit bigger-atleast it lasting a lot longer.

Here is the device pics :

 

[Martaine2005]

Changing the voltage or battery shouldn’t cause any issues providing the new voltage is stepped down to 3.2V.


Martin

 

[Bluejets]

I'd tend to try using quality CR2032 cells first.

 

[Martaine2005]

I'd tend to try using quality CR2032 cells first.

Good point. OP might get up to 6 months then.
I buy CR3032’s on a card of 12 for £1. Testing purposes only!.
But buy quality ones for my car key fobs that last a couple of years.

Martin

 

[Harald Kapp]

Coin cell eliminator.

 

[NVZN]

I'd tend to try using quality CR2032 cells first.

This panasonic is the most high quality ones sold in my country.. Got other brands like maxell but fake maxell is everywhere in stores like a plague.

Maybe tell me some brand of 2032 that u think is high quality, and I'll try to look up. The brand I familiar is only panasonic tho. Is panasonic not good?

Btw the original tuya smart key finder is KTS brand, and same it died 2 months after initial use.

 

[NVZN]

Changing the voltage or battery shouldn’t cause any issues providing the new voltage is stepped down to 3.2V.


Martin

That's the problem, I dunno how to step down that small fraction from 4.2v to 3.2v...most step downs here draws current even at idle (60mA) and it's quite larger than the tuya key fob itself

 

[NVZN]

Coin cell eliminator.

This is good, but sadly I can't get it portable. Because my device is key fob / key finder tracker, shaped keychains so it needs to be portable.

 

[NVZN]

Good point. OP might get up to 6 months then.
I buy CR3032’s on a card of 12 for £1. Testing purposes only!.
But buy quality ones for my car key fobs that last a couple of years.

Martin

What brand is that?

 

[Martaine2005]

You could try two diodes in series.

Martin

 

[Martaine2005]

What brand is that?

Personally use Duracell or Varta.

Martin

 

[Alec_t]

Two alkaline AA or AAA cells will give you ~3V. Non-rechargeable, but should give far longer life than a CR2032.

 

[crutschow]

How about a CR123A 3V lithium?
It has a 1500mAh capacity vs. the CR2032 225mAh rating, so should last at least 6 times as long.

Alternately the largest coin cell is the CR2477 with a 1000mAh capacity, for about 4 times the life of the CR2032

 

[bertus]

Hello,

There is even 5Ah lithium batteries available:
https://www.newark.com/panasonic-batteries/br-cssp/lithium-battery-3v-c/dp/15C6475
https://www.newark.com/panasonic-batteries/br-ct2sp/lithium-battery-3v-c/dp/15C6476
https://www.newark.com/panasonic-batteries/br-cc7p/lithium-battery-3v-c/dp/25C3008

Bertus

 

[NVZN]

How about a CR123A 3V lithium?
It has a 1500mAh capacity vs. the CR2032 225mAh rating, so should last at least 6 times as long.

Alternately the largest coin cell is the CR2477 with a 1000mAh capacity, for about 4 times the life of the CR2032

i dont know how to charge those cr123A ones, all i have here is 3.7V charger (tp4056 and nitecore d4)

or u have recommendation which bms and charger to charge this thing?

 

[NVZN]

Two alkaline AA or AAA cells will give you ~3V. Non-rechargeable, but should give far longer life than a CR2032.

yeah i was thinking about this, its okay its disposable battery atleast lasted far more longer though. Will try it.

 

[NVZN]

Personally use Duracell or Varta.

Martin

havent seen varta cells here since 2007, maybe its not distributed here anymore. Do u familiar with renata brand?

 

[NVZN]

You could try two diodes in series.

Martin

may i know why use 2 diodes ?

 

[crutschow]

i dont know how to charge those cr123A ones,

Those are not rechargeable.

 

[Martaine2005]

may i know why use 2 diodes ?

To drop the voltage by 1V or 1.2V. Each diode has a voltage drop between 0.3V to 0.7V (approx) depending on the diode type. It’s just a crude way rather than dividers or regulators for such a small amount.

Martin