Artisan Power Avaya 3631 Phone Replacement Battery. 1150 mAh Avaya 3631 Replacement Battery Fully replaces battery number 700431489, 700431497 and SMT-W5110B Li-ion Rechargeable Battery Pack| 3.7 Volt | 1150 mAh | Cells Made in Japan Longer Lasting: 1150 mAh capacity rating 15% higher than the OEM batteries. Manufactured by Artisan Power, a leader in premium quality replacement battery packs.