12V and dual-battery setups for Aussie utes and 4WDs

Straight answers to the questions that fill up 4WD forums, with calculators that show their working and sources you can check.

Calculators

• What size DC-DC charger do I need? (sizing calculator plus guide)
• How long will my battery run my fridge?
• Cable size and voltage drop calculator

Guides

• 25A vs 40A DC-DC charger: which one?
• DC-DC chargers with a solar input, explained
• Smart alternators and dual batteries
• Toyota Hilux dual battery setup
• Ford Ranger dual battery setup