“You get what you pay for” is well known and when it comes to batteries, specifically CR2023, it’s a significant difference I experienced. Look at those battery graphs for my 3 BLE temperature/humidity monitors:
3 LYWSD03MMC and their battery status
In 2021 I got myself some Xiaomi LYWSD03MMC and I upgraded/replaced their firmware via this to send out the data via BLE. While they were supposed to last about a year, I was very pleasantly surprised that the included batteries indeed lasted about a year.
I replaced them all in January 2022 with retail Panasonic CR2023 I bought in the local retail electrics shop (Yamada Denki). Price was about 1100 Yen for 4 (275 Yen per piece). As you can see, they lasted even longer: after 1.5 years I replaced two in August 2023 (yellow and green graph) and in November 2023 the 3rd one (blue graph).
I had no spare Panasonic CR2023 in August 2023, so I got some off-brand CR2023. How bad could they be, right? 5 in a blister pack for about half costs per coin cell. The actual brand I forgot. Either OEM, or simply faked brands, or just cheap quality no-name.
Generic off-brand CR2023. Not recommended.
As you can see in the graphs the 2 cells I replaced in August lasted 6 resp. 7 months and their discharge rate was significantly higher.
The 3rd one (the blue one) I replaced it with another retail Panasonic coin cell. And as you can see, the discharge curve is considerably nicer to look at compared to the off-brand ones. It certainly looks like it’ll last well over one year.
I expected minor differences in quality, but it seems that cost cutting (engineering or quality of material) can be done at expenses of the overall quality.
My conclusion: for coin cells, the retail Panasonics are best value for money. While they may be twice as expensive as cheap ones, they also last twice as long. And for me, that’s a good thing.
Harald's Random Stuff 