Many hybrid vehicles predate detailed battery analytics, leaving owners unaware of degradation. A plug-in module could monitor charge cycles and estimate remaining lifespan for older models.
Connect to OBD-II ports to log battery performance over time, with alerts for abnormal voltage drops.
Sell directly to eco-conscious owners through mechanic partnerships, with upsells for replacement part referrals.
Prototype with common Toyota/Lexus models first, given their prevalence in early hybrids.
Risk: Newer models may make this obsolete as built-in analytics improve.