Has anyone observed notable differences in the degradation rates of lithium-ion versus nickel-metal hydride (NiMH) batteries in hybrid vehicles under varying climate conditions? Specifically, I'm interested in empirical data or personal experiences relating to battery temperature management strategies and their long-term impact on capacity retention in models such as the Toyota Prius (NiMH) compared to more recent hybrids utilizing lithium-ion technology. Additionally, are there reliable diagnostic tools or methodologies preferred by the community for monitoring hybrid battery health over extended periods?