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Guides

Battery & DC planning guides.

Clear, calculated answers to the questions people ask before buying batteries, inverters and cable.

Plain-language guides to planning a battery system: how big the bank should be, what an inverter really draws, which system voltage to choose and how much your cables lose. Every number comes from the same published, tested formulas as the calculator.

How to size a LiFePO4 battery bankDaily energy, reserve days, usable depth of discharge and derating—step by step, with a worked example. What size battery for a 1000W, 2000W or 3000W inverter?DC current at 12V, 24V and 48V, and the capacity needed for a given runtime. 12V vs 24V vs 48VHow system voltage changes current, cable loss and heat for the same load. DC cable voltage drop explainedWhy both leads count, why temperature matters, and what voltage drop does not tell you. How to choose a battery monitor and shuntThe ratings and features that matter, and how to match the shunt to your current. RV, van and boat battery sizingThree worked examples with every input shown, from a weekend van to a full-time RV.

How these guides are written

  • Calculated, not guessed. Tables are produced with the calculator’s formula version 1.0.0; inputs are listed so you can reproduce every number.
  • No invented testing. We do not claim to have tested products. Hardware links go to Amazon category searches, labelled as sponsored—see the Affiliate Disclosure.
  • Planning, not installation. Conductor size, fuses and protection must be specified by a qualified installer. See the Safety checklist.