The original Segway lithium battery packs used LiFePO4 cells to make the 73.6V / 5.2Ah battery that was sold for the last 15+ years. The benefits of LiFePO4 are that it is intrinsically safe, has double the cycle life or Li-Ion, and is more tolerant to over discharge to name a few of the major differences. There are plenty of videos available out on the internet which show that the LiFePO4 is a much safer battery if it is over-charged or punctured. The cycle life is going to be the key difference. LiFePO4 cells have an average rated cycle count of ~2000 in comparison to Li-Ion having an average rated cycle count of ~1000. This means that the Li-Ion batteries will likely have approximately 50% of the overall life compared to the older LiFePO4 battery packs under normal use. You may be asking why in the world would anyone wish to go with the new Li-Ion batteries after reading what we just wrote?? The reason is because you can certainly get additional range off the the Li-Ion battery packs compared to the LiFePO4. The "actual range" of the battery has been tested by a Segway dealer that we are acquainted with and we have provided their test results below.
Test environment: 85F temp, 165lb rider, riding around a perfectly flat track at a school until the machine does an emergency shutdown. Batteries were on the machine and plugged in for 24hr prior to testing. Rider held a steady 11-12mph during the test.
LiFePO4 tested on Segway i2 @ 22.6mi
Li-Ion tested on Segway i2 @ 28.4mi
The results clearly show that the Li-Ion will absolutely provide a longer run time per charge but at the expense of life and at an anticipated 2.5x annual operating cost.
LiFePO4 @ $800 per battery = $800 / 8yr @ $100/yr
Li-Ion @ $1000 per battery = $1000 / 4yr @ $250/yr