Question 1

Is AIS-140 enough for an EV fleet?

Accepted Answer

No. AIS-140 is a vehicle location tracking standard — GPS and NavIC position to 5 m CEP, speed, heading and an emergency button. It defines no battery, state-of-charge or energy parameter. Keep it for compliance and source battery and charging data separately.

Question 2

What is the difference between state of charge and state of health?

Accepted Answer

State of charge is how full the pack is right now, as a share of the capacity it currently has. State of health is how much of the original capacity remains. A pack at 100% state of charge and 78% state of health is completely full and holds 78% of what it held when new.

Question 3

Can we get battery state of health from an OBD dongle?

Accepted Answer

Sometimes. It depends on whether the vehicle publishes the value on its CAN bus and whether you hold the manufacturer's message definitions to decode it. On several Indian commercial EVs it is not exposed, and third-party hardware can affect warranty terms — get both answers in writing first.

Question 4

Why does the state-of-charge gain not match the kWh the charger billed?

Accepted Answer

Charging losses and a different metering point. The charger meters energy taken from the grid; state of charge reflects energy that reached the cells. Roughly a tenth is lost in the charger, cabling and thermal management, and the gap widens on DC fast charging and in high ambient temperatures.

Question 5

How long should an EV fleet retain telematics history?

Accepted Answer

For the life of the asset. Battery decisions are trend decisions, so per-vehicle state of charge, consumption and charging-session records should be kept until the vehicle is sold, and full historical export should be a contract term rather than a favour.

state of charge

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