Li-ion AA and AAA batteries, i.e. lithium-ion replacements for AA and AAA batteries: https://www.hurt.com.pl/baterie-alkaliczne-aa-lr6-everactive-pro-alkaline-kartonik-10-sztuk-p15516.html
Xtar 14500/AA/R6 3.7 v Li-ion 800mAh rechargeable battery with protection
Capacity: 800mAh
Dimensions: 14, 3mm x 50, 5mm
Protected against: Discharge, overcharge, overload, short circuit
4x Rechargeable Battery Xtar R03 / AAA 1,5V Li-ion 680mAh with Protection (BOX)
Nominal voltage: 1.5V
Minimum capacity: 680mAh
typical capacity: 750mAh
dimensions: 10,3mm x 44,5mm
protected against: discharge, overcharge, overload, short circuit
number of charge and discharge cycles: more than 1200 cycles
SET OF 4 PIECES packed in a plastic container
4x Xtar R6 / AA 1.5V Li-ion 2000mAh battery with protection
nominal voltage: 1.5V
minimum capacity: 2000mAh
typical capacity: 2200mAh
Dimensions: 14.5mm x 50mm
protected against: discharge, overcharge, overload, short circuit
number of charge and discharge cycles: more than 1000 Cycles
SET OF 4 PIECES packed in a plastic container
4x Xtar R6 / AA 1.5V Li-ion 2500mAh battery with protection
HIGH CAPACITY | DISCHARGE INDICATION
nominal voltage: 1.5V
minimum capacity: 2400mAh
Typical capacity: 2500mAh
Dimensions: 14.5mm x 50mm
protected against: discharge, overcharge, overload, short circuit
number of charge and discharge cycles: more than 1200 Cycles
SET OF 4 PIECES packed in a plastic container