4 PACK of Philips MultiLife NiMH Rechargeable Batteries - Choose AAA 1000mAh OR AA 2700mAh Batteries - An 8 slot battery charger is also available (works for both AA and AAA) -
MultiLife Akkumulátor R03B4A90/10 | Philips
MultiLife Akkumulátor R6B4RTU20/10 | Philips
6 x AAA Rechargeable batteries for Philips SBC HB550S Headphones 700mAh NiMh | eBay
User manual Philips MultiLife SCB1490NB (English - 2 pages)