Re: 30 year batteries?
Date: 03-25-2020 - 16:02
No reason why not, if designed and operated right.
Li-Ion batteries in cars that have a big enough battery to have a 200+ mile range are likely to be at least 20-year propositions. Teslas used in rental operations have accumulated over 300K miles on the original batteries with only modest capacity degradation; degradation has been related more to time than mileage. The primary factor in determining the life of Li-Ion batteries is the depth of discharge: yes, the batteries do degrade rapidly when near-fully discharged before recharging; while best-case keeps the charge between about 30-80% with full charging only when a trip requiring maximum range is planned. Fast, high-current charging is also something that degrades the battery, so that should only be done when needed (such as recharging while on a road trip) with normal charging being Level 2 (240V, 32-40A) or trickle charging (typically 120V convenience charging).
EVs got the reputation for massive battery degradation in the days of the "compliance cars" with driving ranges of around 100 miles. They had relatively small batteries and poor battery (temperature, especially) management, and had to discharge them deeply to get the expected range. The result in most of them was rapid degradation, on the order of 10-20% a year with moderate driving. One person I know from church has a 4-year-old Ford Focus electric that started (new) with a 120 miles rated range and now (with a 50+ mile daily round trip commute and full recharge every night) is down to 60-70 miles. Early models of the Nissan Leaf have a very bad reputation for battery failure. Newer EVs with longer range don't degrade that much, because they don't get as deeply discharged in normal operation; I just got a used Chevy Bolt with about 35K miles, and it still reports a full-battery range of 190-200 miles with average driving and 240ish maximum - essentially as new.
Trains don't have the space and weight limitations of cars, so it's likely that Siemens is using large-capacity batteries that are seldom discharged below 40-50%, and are kept in that sweep spot of 30-80% most of the time. Having frequent availability of overhead power lines helps with that. With such a system, a 30-year battery is very reasonable to expect.