To determine battery life, on a full charge, the following rule of thumb can be applied:

Standby time = Battery Capacity (mAh) / Idle current (mA)

Call time (voice or data) = Battery Capacity (mAh) / Call current (mA)

Example 1 – Standby time:

A 600mAh rated Li-Ion battery, from fully charged (around 4.2V) to the module cutoff point (3.2V) will provide around 95% of its total charge capacity. For a standby (idle) current of 18mA, the module will typically provide

600*0.95/18 = 32 hours standby time

Example 2 – Call time:

An 1800mAh rated Li-Ion battery fully charged, transmitting maximum power on a low-band (850/900MHz) channel may consume an average 320mA, therefore the module would typically provide

1800*0.95/320 = 5 hours 20 mins call time

LZT 123 1834

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