Quote:
Originally Posted by ng2951
If they are using a different technology, then life could be much longer....
|
The battery packs in MOST hybrid cars, e.g., Toyota, Honda, non-plug in Ford Escape, are currently Ni-MH, the same 1.3V (nominal) cells as you use at home. The "Gen-2" Prius had 228 of these cells in Series, arranged in 38 modules of 6 cells each. This offered a nominal maximum voltage of about 275 volts. The current "Gen-3" Prius actually has fewer batteries, using just 28 modules. Same modules, nominal voltage is therefore reduced to about 200 volts. But, the new Toyota systems add a fancy inverter which raises the working voltage to 500v, while the old ones (Gen-1 and Gen-2) just used the battery output voltage unchanged.
Because Ni-MH batteries don't like being drained to a low state of charge, Toyota only runs them down to about minimum level of about 50% charge. This is one area where future "plug-in" hybrids could be made differently-- using either deep-cycle lead-acid types (including Gel cells) which are cheap and reliable but but very heavy for the amount of energy which can be stored and actually used; or lithium-ion, which are expensive but better than NiMH in nearly all other characteristics (max number of charge cycles, energy density, etc.) The big problem with Li-ion right now is, they just wear down over time, typical life expectancy is only 3-4 years.
Nearly ALL technologies are under continuing development: li-ion "thin film", lead acid batteries built with carbon foam, li-ion with silicon nanowires, and etc. Also, lots of research is going into energy storage via flywheels, rather than batteries. The technology is still developing quickly, and some of the aftermarket plug-into-the-wall conversion kits which are already available replace the original battery packs with li-ion as part of their kits.