The current 35 KwH battery would be about 1100 pounds. That is good for a 125-150 mile range. The next generation batteries that the Lightning is getting are supposed to have higher energy density comparable to the Tesla. They also have an 85% charge retention at 20,000 cycles (read: 5 million miles under optimum conditions). For comparison, the 53 KwH battery pack in the tesla is about 1000 pounds with an estimated life of 100,000 miles. I believe the quote from altair was at a an absolute minimum with the least care taken with recharges ect, we should expect 8 times the life of a normal lithium ion pack.