Can you recommend electric car manufacturer websites for researching battery details and warranty information?

Yes — for the most reliable battery and warranty details, I’d recommend starting with the official manufacturer websites and, where available, their owner manuals / warranty PDFs. Those are usually the best sources for current, model-specific information.

Good manufacturer websites to research

• Tesla — model specs, battery info, warranty terms, owner manuals
  https://www.tesla.com/
• Hyundai — EV model pages, warranty info, manuals
  https://www.hyundaiusa.com/ (US)
  https://www.hyundai.com/ (global)
• Kia — EV specs, battery/warranty coverage
  https://www.kia.com/
• Ford — Mustang Mach-E / F-150 Lightning battery and warranty details
  https://www.ford.com/
• Chevrolet — Bolt / Equinox EV / Blazer EV specs and warranties
  https://www.chevrolet.com/
• Nissan — LEAF battery and warranty information
  https://www.nissanusa.com/
• Volkswagen — ID.4 and EV battery coverage
  https://www.vw.com/
• BMW — i-series EV battery/warranty documentation
  https://www.bmwusa.com/
• Mercedes-Benz — EQ line battery and warranty info
  https://www.mbusa.com/
• Audi — e-tron / Q4 e-tron battery and warranty info
  https://www.audiusa.com/

What to look for on the site

Search for:

• Battery capacity: kWh size, usable vs. total capacity
• Range estimates: EPA/WLTP range
• Battery warranty: years and mileage, plus degradation coverage if listed
• Vehicle limited warranty and powertrain warranty
• Owner’s manual or battery care guide
• Spec sheet / brochure / vehicle comparison pages

Tip

Warranty details can differ by:

• country/region
• model year
• trim level
• battery chemistry

If you want, I can also give you a short list of the best EV websites by region (US, UK/EU, Canada, Australia) or make a comparison table of battery warranties for specific brands.