The Mychron5 Rechargeable Lithium Spare Battery. Save time and money with this rechargeable lithium battery, which lasts more than ten hours, saving on 9V batteries.
Forget the expensive and short-lasting traditional 9V batteries. The MyChron5 rechargeable lithium battery lasts more than ten hours. Charge it as you do with your cell and just enjoy your racing all day long.
Of course, MyChron5 can also be powered by an external 12V power source.