Maxabaker,
HIDs become more efficient as wattages go up, but I assume you know probably know that. 2,000 watts for 24 watts seems pretty optimistic and likely at the bulb.
10 years self for a charged rechargeable lithium cell, that's just plain stupid and insulting. Rechargeable lithiums last about 3 years or a little more. Non-rechargeables are 10 years. Company seems a little confused.