If you are willing to have to change cells 3 to 5 times as often you might consider rechargeable coin cells. There are for example rechargeable 2032 cells that go for around $15-20 for 4 with a charger.
The catch is that their capacities are from about 45 mAh to 75 mAh depending on brand. A non-rechargeable 2032 is around 225 mAh.
Once you have the rechargeable cells and the charger they are essentially free for the rest of their lifetime. In the European country with the highest electricity prices the cost to charge a 45 mAh cell 5 times or a 75 mAh cell 3 times would be under 1/2000th of a Euro.
With the price of individual non-rechargeable cells being around the same price as rechargeable cells plus charger it is almost a no-brainer if you are OK with having to change cells more frequently in your devices.
BTW, the math is similar for AA and AAA batteries, except there the rechargeable batteries themselves cost 3 or 4 times as much as non-rechargeable batteries. So with these if you are only using a handful of batteries a year you might never break even switching to rechargeables.
Like the rechargeable coin cells rechargeable AA and AAAs are essentially free to operate once you have them. Recharging a 2000 mAh NiMH AA like a Panasonic Eneloop would take less than 1/800th of a Euro in the most expensive European country.
Lifetimes of the Eneloops seem pretty good. I've got some 1st generation AA and AAAs that are at least 15 years old (I don't remember exactly when I bought them, but I know I bought them at Circuit City which went out of business in 2008) and some 4th generation AAs that I bought in 2014.
Pretty much all my AA and AAA battery use since 2008 has been on these.
The 1st gen AAs now mostly have capacities in the 1800-1900 mAh range, which is slightly under spec (spec is min 1900 mAh, typical 2000 mAh). The 1st gen AAAs are currently in the 790-840 mAh range (spec is min 750 mAh, typical 800 mAh). The 4th gen AAs are mostly in the 1900-2000 mAh range (spec is min 1900 mAh, typical 2000 mAh).
Of the 24 1st gen AAs I bought, 2 have died. Of the 16 1st gen AAAs I bought, 3 have died. Of the 16 4th gen AAs I bought the 15 I know of are still fine.
The catch is that their capacities are from about 45 mAh to 75 mAh depending on brand. A non-rechargeable 2032 is around 225 mAh.
Once you have the rechargeable cells and the charger they are essentially free for the rest of their lifetime. In the European country with the highest electricity prices the cost to charge a 45 mAh cell 5 times or a 75 mAh cell 3 times would be under 1/2000th of a Euro.
With the price of individual non-rechargeable cells being around the same price as rechargeable cells plus charger it is almost a no-brainer if you are OK with having to change cells more frequently in your devices.
BTW, the math is similar for AA and AAA batteries, except there the rechargeable batteries themselves cost 3 or 4 times as much as non-rechargeable batteries. So with these if you are only using a handful of batteries a year you might never break even switching to rechargeables.
Like the rechargeable coin cells rechargeable AA and AAAs are essentially free to operate once you have them. Recharging a 2000 mAh NiMH AA like a Panasonic Eneloop would take less than 1/800th of a Euro in the most expensive European country.
Lifetimes of the Eneloops seem pretty good. I've got some 1st generation AA and AAAs that are at least 15 years old (I don't remember exactly when I bought them, but I know I bought them at Circuit City which went out of business in 2008) and some 4th generation AAs that I bought in 2014.
Pretty much all my AA and AAA battery use since 2008 has been on these.
The 1st gen AAs now mostly have capacities in the 1800-1900 mAh range, which is slightly under spec (spec is min 1900 mAh, typical 2000 mAh). The 1st gen AAAs are currently in the 790-840 mAh range (spec is min 750 mAh, typical 800 mAh). The 4th gen AAs are mostly in the 1900-2000 mAh range (spec is min 1900 mAh, typical 2000 mAh).
Of the 24 1st gen AAs I bought, 2 have died. Of the 16 1st gen AAAs I bought, 3 have died. Of the 16 4th gen AAs I bought the 15 I know of are still fine.