Amazon.com: Replacement for Sennheiser BA300 Battery - Compatible with Sennheiser RS 4200 RR 4200 Set 830-TV RI 830 Set 830 S RI 830 S is 410 RI 410 Headphone Battery : Electronics
Amazon.com: Sennheiser BA300 Lithium Polymer Rechargeable Battery For Sennheiser Set 900, Set 840, Ri 900 : Electronics
12V Lithium Batteries for RV, Marine, Solar, Golf Cart and Automotive
Inogen One G3 16 cell battery - Oxigo
Delo DELO LITHIUM-ION-ACCU PLFP-18R 12V/5AH,CCA 300A