Batteries, 6mAh, 1.55V
From Amazon
Varta 14501335 Silver Oxide Button Cell V335 Pack of 1
Conrad Electronic
Varta Button cell 335 1.55 V 1 pc(s) 6 mAh Silver oxide SILVER Coin V335/SR512 NaBli 1
BatteryUpgrade
Varta V335 (SR512SW) Coin cell battery (Amount 1)