Kenwood KNB-81L is the spare or replacement Lithium Ion IP67 rated battery for the ProTalk NEXEDGE NXP500 series radios. This battery is 2200 mAh and last 15 hours on average.
Battery for Crestron 81-207-392012 81-215-360012 TPMC-8X-BTP 6502269 TPMC-8X - Walmart.com
MacBook Pro 15" A1398 Mid 2015 Top Case Keyboard Battery 81% TrackPad Bottom ... | eBay