Inverter & Battery· Money Saver

Inverter Battery Charging Time & Unit Cost Calculator

Find out how many hours it takes to fully charge your inverter battery after a power cut, and the exact electricity bill cost (kWh units consumed) based on charging current and grid tariff.

Estimated Full Re-Charge Time
10Hours27Mins

To charge from 80% discharge using 14A current.

Electricity Units (kWh) Consumed:2.14 Units
Cost Per Full Charge:16.1
Charging Current Setting:14 Amperes
Recommended Current Rule

Safe charging current is typically 10% of battery Ah. For a 150Ah battery, set your inverter charger switch to 12A-15A to avoid boiling the electrolyte.

Inverter Charging Current:14 Amps
8A (Slow / Eco)14A (Standard)20A (Fast)
Electricity Tariff Rate (₹/kWh):7.5/Unit
₹4 (Subsidized)₹7.5 (Average)₹14 (Commercial)

How This Calculation Works & Technical Formula

Charging Time (h) = (Battery Ah / Charging Amps) × 1.25 (Coulombic efficiency loss). Units (kWh) = (Battery V × Ah × 1.25) / 1000.

How to use this tool:

  1. Enter battery capacity in Ah (e.g. 150Ah).
  2. Enter inverter charging current in Amperes (typically 10A to 15A for 150Ah).
  3. Set initial discharge level (e.g. 80% discharged).
  4. Enter your local electricity rate per unit (e.g. ₹7/unit) to view full charge cost.

Frequently Asked Questions

How many electricity units are consumed to charge a 150Ah battery?+

A standard 12V 150Ah battery has a nominal capacity of 1.8 kWh. Accounting for charging losses (~20-25%), a full charge consumes approximately 2.1 to 2.3 units (kWh) of electricity, costing about ₹15 to ₹18 at average Indian tariffs.

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