How many cells are in an electric scooter battery?

It depends on the voltage, the capacity and the cell size. A typical 60 V, ~3.5 kWh scooter pack built with 21700 NMC cells is 16 cells in series and about 12 in parallel, which is roughly 190 cells. The same energy from 18650 cells needs about twice as many.

Which is better for an electric scooter, LFP or NMC?

NMC gives more range for the same weight, which is why most Indian e-scooters use it. LFP is safer, tolerates heat better, lasts more cycles and costs less per kWh, but it is heavier. For a light, long-range scooter choose NMC with a good BMS. For a hard-working fleet or delivery vehicle, LFP is often the better value.

How long does an EV battery last in India?

It depends mostly on chemistry, heat and usage. NMC cells are commonly rated for roughly 1,000–2,000 cycles and LFP for roughly 2,000–6,000 cycles before dropping to about 80% capacity. With sensible charging and protection from heat, many packs last several years. Check your warranty, which usually sets years, kilometres and a minimum State of Health.

How do I calculate the battery size for an EV?

Energy needed (Wh) = range (km) × consumption (Wh/km) ÷ usable fraction (about 0.9). Pick the series count from your system voltage (for example 16S for a 60 V NMC pack), then parallel count = energy ÷ (pack voltage × cell Ah), rounded up. Finally, check that the peak current per cell stays within the cell's continuous rating.

Can I build my own lithium battery pack at home?

Pack building can be learned, but lithium-ion cells can catch fire if they are shorted, damaged or badly connected. Start with low-voltage bench projects, use proper tools (spot welder, IR tester, BMS), work in a safe area, and ideally learn under supervision. Packs used on road-registered vehicles in India must meet AIS-156 or AIS-038 safety standards.

What is a BMS and do I need one?

A Battery Management System monitors every cell group's voltage, the current and the temperature. It protects the pack from over-charge, over-discharge, over-current, short circuits and overheating, and it balances the cells. Every lithium-ion EV pack needs one, matched to its series count, chemistry and current.

Why does my EV's range drop in winter or summer?

In the cold, lithium-ion chemistry slows down, so less capacity is available and the BMS may limit charging. In extreme heat, the BMS may reduce power to protect the cells, and long-term heat exposure speeds up ageing. Parking in the shade and letting the pack cool before charging helps a lot.

What is Battery Aadhaar?

Battery Aadhaar, or the Battery Pack Aadhaar Number (BPAN), is a proposed Indian system that gives every EV battery pack a unique 21-character ID with a QR code. It links to static data (maker, specs, materials, carbon footprint) and dynamic data on condition and usage, so a battery can be traced from production to recycling. Draft guidelines were released in January 2026.

Which course should I take to become an EV battery technician or engineer?

If you have an ITI, diploma or service background and want hands-on technician work, start with DIYguru's 3-month CEVT program. If you are an engineering student or graduate aiming for battery or BMS engineering, the 6-month Battery & BMS Advanced Nanodegree fits best. For a complete EV engineering career across battery, powertrain and embedded systems, choose the 12-month PG Program.

The DIY Guide to EV Batteries & Cells

How lithium-ion cells work, how they become a battery pack, how to size one for a scooter or e-rickshaw, and how to keep your battery healthy. It is written for students, technicians and EV owners, with a free pack calculator.

By DIYguru Battery Lab Updated 22 October 2026 Read, explore & practise

The short answer

An EV battery pack is made of many small lithium-ion cells. Cells are wired in series to raise the voltage and in parallel to raise the capacity, then a Battery Management System (BMS) watches every cell and protects the pack. Pack energy (Wh) = pack voltage × capacity (Ah). Divide the usable energy by your vehicle's consumption (Wh/km) and you get the range.

Chapter 1

How an EV battery works: cell, module and pack

Activity 01 · Watch the movement

One cell. Two directions.

Switch between using energy and storing energy. The dashed paths show movement; speed is illustrative.

Discharge: lithium ions travel from the negative electrode to the positive electrode. Electrons flow through the external load, providing electrical energy.

The electrolyte transports ions. The separator keeps the electrodes apart. Electron flow is opposite to conventional current.

Every EV battery, from a 250 W e-cycle to an electric car, is built from the same basic unit: the lithium-ion cell.

Inside a lithium-ion cell

A cell has two electrodes separated by a thin porous film. The cathode (positive side) is a lithium metal oxide or phosphate coated on aluminium foil, and its material gives the cell its name: LFP, NMC and so on. The anode (negative side) is usually graphite coated on copper foil. A liquid electrolyte lets lithium ions move between them, and the separator keeps the electrodes from touching.

When you charge, the charger pushes lithium ions out of the cathode, through the electrolyte, and into the graphite anode, while electrons flow through the external circuit. When you ride, the process reverses: ions travel back to the cathode and the electrons flow through your motor controller to do work. No lithium metal is formed in normal use. The ions simply shuttle back and forth, which is why these cells last hundreds or thousands of cycles.

From cell to pack

A single cell gives only about 3.2–3.7 V, so vehicles combine many of them:

Cell: the basic electrochemical unit (cylindrical, prismatic or pouch).
Module: a group of cells joined by busbars or nickel strips, with voltage and temperature sensing wires.
Pack: modules plus the BMS, fuse, contactor or MOSFET switch, connectors, thermal parts and a sealed enclosure.

Many two-wheeler packs skip the module level and connect cells straight into a pack. This is often called cell-to-pack. Cars and buses usually keep modules because they make large packs easier to assemble and service.

Figure 1. Cells are grouped into modules, and modules plus electronics and an enclosure make the pack that goes into the vehicle.

Eight terms you'll see everywhere

Nominal voltage (V): The average voltage during discharge, for example 3.2 V for LFP or 3.6 V for NMC. Pack voltage = cells in series × nominal voltage.
Capacity (Ah): How much charge the cell or pack holds. A 5 Ah cell can supply 5 A for about one hour.
Energy (Wh / kWh): Voltage × capacity. This is the number that decides range. 60 V × 50 Ah = 3,000 Wh = 3 kWh.
C-rate: Current relative to capacity. 1C on a 5 Ah cell is 5 A, and 2C is 10 A. Datasheets give maximum charge and discharge C-rates.
SoC (State of Charge): The "fuel gauge", in % of current capacity. The BMS estimates it.
SoH (State of Health): Today's capacity compared with when the battery was new. 80% SoH means it holds 80% of its original energy.
DoD (Depth of Discharge): How much of the capacity you use in a cycle. Shallow cycles generally make cells last longer.
Internal resistance (mΩ): Lower is better. High resistance means more heat, more voltage drop under load, and often a tired or poor-quality cell.

Chapter 2

Cell formats: 18650, 21700, 32700, 46-series, prismatic and pouch

Cylindrical, prismatic and pouch battery cell illustrations shown side by side — Cell-format image: CRBAman, Wikimedia Commons, CC BY-SA 4.0. Image unchanged; displayed at responsive size. Shape does not identify chemistry.

The format is the cell's physical shape. It affects how a pack is assembled, cooled and repaired, not just how much energy fits.

Cylindrical cell names follow a simple code: the first two digits are the diameter in mm and the next digits are the length. So a 21700 is 21 mm wide and 70 mm long. Prismatic cells are flat rectangular cans, and pouch cells are soft, foil-wrapped sheets.

Figure 2. Cylindrical cells drawn roughly to scale with each other; prismatic and pouch cells shown schematically (they are much larger).

Format	Typical capacity	Where you'll find it in India	Strengths	Watch-outs
18650	2.5–3.5 Ah	E-cycles, older e-scooters, laptops, DIY packs	Cheap, everywhere, easy to test and replace	Many cells per pack means many welds; lots of fakes in the market
21700	4–5 Ah	Most modern e-scooters and e-motorcycles	About 1.5× the capacity of an 18650, so fewer cells and welds	Choose "high-drain" or "energy" type to match your current needs
32700 / 32650	5–6 Ah	LFP packs for e-rickshaws, budget scooters, solar storage	LFP safety and long cycle life in a weld-friendly can	Heavier per kWh than NMC cylindrical cells
46-series (4680, 46100)	Large-format	New-generation packs; Ola Electric has announced in-house 46-series cells	Fewer, bigger cells; good for automated production	Still new, with limited availability for small builders
Prismatic	50–300 Ah	E-rickshaws, L5 cargo, cars, buses, energy storage	Very few connections; bolt-on busbars; neat packaging	One bad cell is a big part of the pack; needs compression fixtures
Pouch	20–100+ Ah	Some cars and premium two-wheelers	Highest packing efficiency; light	Needs a rigid frame and pressure; can swell; hard for DIY

Rule of thumb for buildersUse cylindrical cells (21700 or 32700) for scooters and small vehicles where you need flexible shapes. Use prismatic LFP for e-rickshaws and loaders where space is boxy and you want fewer connections.

Chapter 3

Battery chemistries: LFP vs NMC, and what's coming next

Chemistry decides a battery's voltage, energy density, safety margin, lifespan and cost. No single chemistry wins on everything.

In India today, two chemistries dominate. NMC (nickel manganese cobalt) holds roughly 70% of the electric two-wheeler segment because it packs more energy into a small, light scooter battery. LFP (lithium iron phosphate) is gaining across other vehicle categories, such as three-wheelers, buses, cars and energy storage, because it is safer, cheaper and lasts longer. Next-generation options such as LMFP, sodium-ion and solid-state are expected to grow through 2032.

LFP (Lithium Iron Phosphate)

Chemistry	Nominal cell voltage	Cell energy density*	Cycle life*	Thermal safety	Best fit
LFP	3.2 V	~140–200 Wh/kg	2,000–6,000	Excellent	E-rickshaws, L5 cargo, buses, fleets, storage
NMC	3.6–3.7 V	~200–280 Wh/kg	1,000–2,000	Good (needs a strong BMS)	E-scooters, e-motorcycles, long-range cars
LMFP	Higher than LFP	~15–20% above LFP	Still maturing	Very good	Next-gen affordable cars and two-wheelers
Sodium-ion	~3.0–3.1 V	~100–175 Wh/kg	2,000–5,000 (claimed)	Very good	Entry two-wheelers, cold climates, storage
LTO	~2.3–2.4 V	~60–110 Wh/kg	10,000+	Excellent	Ultra-fast-charge buses, industrial niche

*Typical published ranges. Exact values vary by manufacturer and test conditions (C-rate, temperature, end-of-life threshold). Always use the datasheet of the actual cell you buy.

Which should you pick?

Choose NMC when weight and space are tight and you want maximum range per kg, as in a typical scooter.
Choose LFP when the vehicle works hard every day in Indian heat, cost matters, and some extra weight is fine, as in an e-rickshaw, a delivery fleet or a loader.
Watch sodium-ion: it uses no lithium or cobalt and performs well in the cold, and Indian firms are investing in it. Expect it first in low-cost two-wheelers and storage.

Chapter 4

How to read a cell datasheet (and spot fake cells)

Activity 02 · Read like an engineer

A datasheet is a set of conditions

Expand each line of this fictional teaching cell. These values are examples, not a procurement specification.

3.6 V nominal / 4.2 V maximum

Nominal voltage is used for energy estimates. Maximum charge voltage is a separate limit. A 10S example is 36 V nominal and 42 V at its cell-defined upper limit.

5.0 Ah rated capacity

Capacity depends on the stated test current, temperature and cut-off voltage. Compare cells only when the test conditions match.

10 A continuous discharge

Check thermal conditions and cooling assumptions. A pulse rating cannot replace a continuous rating. At 10 A, this example cell operates at 2C.

18 Wh nominal energy

3.6 V × 5.0 Ah = 18 Wh. Delivered energy varies with load, temperature, age and the allowed voltage window.

Cycle life to 80% capacity

Read the full test: depth of discharge, charge rate, discharge rate and temperature. A cycle-life number without these conditions is incomplete.

Charge temperature window

Charge and discharge limits may differ. Read the exact cell specification and the vehicle manufacturer’s instructions; never infer one limit from the other.

Before you buy a single cell, read its datasheet. These are the lines that matter for an EV pack.

Datasheet line	Example (21700 NMC)	What it tells you
Nominal voltage	3.6 V	Used to calculate pack voltage and energy
Charge cut-off voltage	4.2 V	Maximum voltage. Your charger and BMS over-voltage limit are set from this
Discharge cut-off voltage	2.5 V	Absolute minimum. Most BMS settings stop a little higher (around 2.8–3.0 V) to protect cell life
Rated capacity	5,000 mAh @ 0.2C, 25 °C	Capacity measured at a gentle rate. At high current you'll get somewhat less
Max continuous discharge	10 A	The current one cell can supply continuously. This decides how many cells you need in parallel for your motor
Max charge current	0.3–0.7C	Limits how fast you can charge
AC internal resistance	≤ 20 mΩ	Used to grade and match cells. Mismatched cells age unevenly
Cycle life	500–1,000+ cycles to 80%	Check the test conditions; real life depends on heat and DoD
Operating temperature	Charge 0–45 °C · Discharge −20–60 °C	Never charge below 0 °C or above the limit. Your BMS should enforce this
Weight	~69 g	Used for pack weight estimates

Red flags for fake or re-wrapped cellsAn 18650 that claims "9,900 mAh", a weight much lower than the datasheet, no batch code laser-etched on the can, prices far below the market, or high internal resistance when tested. A real 18650 tops out at around 3.5 Ah. Buy from authorised distributors, ask for the datasheet and invoice, and test a sample before you build.

Worked example: reading a pack label

A scooter battery label says 60V 30Ah LFP.

Energy = 60 V × 30 Ah = 1,800 Wh (1.8 kWh).
LFP cells are 3.2 V nominal, so a "60 V" LFP pack is usually 20 cells in series (20 × 3.2 = 64 V).
At a typical 30 Wh/km and 90% usable capacity: 1,800 × 0.9 ÷ 30 ≈ 54 km real-world range.

Chapter 5

Series and parallel: what "16S12P" means and how to size a pack

Activity 03 · Build the concept

Change the layout. See the maths.

Each column is a parallel group. Connecting those groups in series increases voltage. This is a conceptual map, not a physical wiring plan.

Series groups: 4SCells per group: 3PExample cell

Identical, matched cells assumed. Actual current capability depends on the cells, connections, protection and thermal design.

Two rules explain every battery pack you'll ever see.

Series (S) adds voltage. Connect positive to negative and the voltages add up while the capacity stays the same.
Parallel (P) adds capacity and current. Connect positive to positive and the capacities add up while the voltage stays the same.

Packs are described as xSyP. A 16S12P pack has 16 groups in series, and each group has 12 cells in parallel. That makes 192 cells in total.

Figure 3. In a 4S2P pack, two cells share each group (parallel) and the four groups are stacked in series. The BMS senses the voltage of each group, not each cell.

Standard voltage classes

Vehicle voltages like "48 V" or "60 V" are classes, not exact numbers. Builders use these common series counts:

System class	NMC (3.6 V cells)	Voltage window (NMC)	LFP (3.2 V cells)	Voltage window (LFP)
36 V	10S → 36 V	30.0–42.0 V	12S → 38.4 V	30.0–43.8 V
48 V	13S → 46.8 V	39.0–54.6 V	16S → 51.2 V	40.0–58.4 V
60 V	16S → 57.6 V	48.0–67.2 V	20S → 64.0 V	50.0–73.0 V
72 V	20S → 72.0 V	60.0–84.0 V	24S → 76.8 V	60.0–87.6 V

Window = series count × cut-off voltages (NMC 3.0–4.2 V, LFP 2.5–3.65 V). Your motor controller must accept the full window.

The 4-step sizing method

Pick the series count from your controller's voltage class and your chemistry (table above).
Find the energy you need: range (km) × consumption (Wh/km) ÷ usable fraction (about 0.9).
Parallel count for energy: energy needed ÷ (pack nominal voltage × cell Ah), rounded up.
Check current: motor peak power ÷ pack voltage gives the peak current. Divide by the parallel count. If each cell would exceed its continuous rating, add more cells in parallel.

Worked example: a 60 V city scooter with 100 km range

NMC 21700 cells (3.6 V, 5 Ah, 10 A) → 60 V class = 16S → 57.6 V nominal.
Energy needed = 100 km × 30 Wh/km ÷ 0.9 = 3,333 Wh.
Parallel = 3,333 ÷ (57.6 × 5) = 11.6 → 12P.
Peak current at 2.5 kW ≈ 2,500 ÷ (57.6 × 0.85) ≈ 51 A → 51 ÷ 12 ≈ 4.3 A per cell, well within 10 A ✔

Result: 16S12P = 192 cells, 57.6 V, 60 Ah, 3.46 kWh, about 104 km.

Don't want to do this by hand? Enter your own vehicle, range and cell in the calculator below.

Use the Pack Calculator ↓

Free tool

EV Battery Pack Calculator

Teaching estimates only: cell presets and prices are illustrative, not supplier quotations or verified product specifications. BMS, fuse and charger outputs are preliminary arithmetic examples, not validated component selections. Final design requires cell datasheets, fault-current coordination, thermal assessment and controller compatibility.

Pick a vehicle, a range and a cell. You'll get the series/parallel configuration, cell count, voltage, kWh and weight instantly. Unlock the full build sheet to get BMS, charger and fuse ratings, a cell layout with balance taps, a cost estimate and a printable checklist.

1. Your vehicle & target

Vehicle type

Target range 100 km

Energy use (Wh/km)

System voltage

Cell

Advanced settings

Motor peak power (W)

Used to check the current each cell must deliver.

Usable capacity 90%

The share of capacity you'll actually use. Keeping a reserve extends cell life.

Price per cell (₹)

Indicative retail price. Replace it with your supplier's quote.

2. Your pack

16S12P

192 cells · 21700 NMC

57.6 VNominal voltage

60 AhCapacity

3.46 kWhEnergy

104 kmEstimated range

48.0–67.2 VVoltage window

~17.9 kgEstimated pack weight

Get the full build sheet (free)

BMS and charger specification, fuse rating, current per cell, a cell layout with balance-tap numbering, a cost estimate and a printable build-and-test checklist.

Estimates are for learning and early design. Real range depends on riding style, load, terrain, temperature and drivetrain efficiency. Always verify against the datasheets of the exact cells, BMS and controller you use.

Chapter 6

The Battery Management System (BMS) explained

Activity 04 · Inspect a fault

Pack voltage never tells the whole story

Choose a simulated condition in this fictional four-group pack. The examples explain BMS behaviour; they are not recommended protection thresholds.

Why balancing is not a repair

Balancing manages differences in state of charge. It does not restore lost capacity or fix a damaged cell. Persistent group divergence needs a qualified diagnostic assessment.

The BMS is the pack's brain and bodyguard. A lithium-ion pack without a BMS is unsafe, full stop.

What a BMS does

Monitors the voltage of every series group, the pack current, and temperatures at several points.
Protects by cutting the circuit on over-voltage, under-voltage, over-current, short circuit, and over- or under-temperature.
Balances the groups so they stay at the same state of charge. Most BMS boards use passive balancing, which bleeds a little energy from the highest groups as heat. Active balancing moves energy between groups instead.
Estimates SoC (usually coulomb counting corrected by voltage) and, in better systems, SoH.
Communicates over CAN, UART or Bluetooth with the vehicle control unit, the charger and the dashboard.

Figure 4. A typical BMS: the monitoring IC measures every series group, the microcontroller decides, and the switch in the main power path disconnects the pack when a limit is crossed.

How to choose a BMS for your pack

Match the series count and chemistry exactly. A 16S LFP BMS uses different voltage limits than a 16S NMC BMS.
Rate it for your current. Its continuous discharge rating should be at or above your motor controller's maximum current, with some margin.
Check the charge current rating against your charger.
Temperature sensors: at least two to three NTCs placed in the hottest parts of the pack.
Communication: a "smart" BMS with CAN or Bluetooth lets you read cell voltages and fault logs. This is invaluable for diagnostics.

Hardware BMS vs smart BMSA basic hardware BMS only protects. A smart BMS also logs data and talks to the vehicle. For any real vehicle, choose a smart BMS: most battery faults are found by reading group voltages and error history, not by guessing.

Chapter 7

Building a lithium-ion battery pack: the process, done safely

Activity 05 · Follow the engineering workflow

From requirements to validation

Explore the evidence a professional team needs at each stage. This is a planning walkthrough, not live-pack assembly instruction.

Record to keep

Safety first, alwaysLithium-ion cells store a lot of energy. A short circuit, a crushed cell or a bad weld can cause fire and toxic smoke within seconds. Learn on low-voltage bench packs first, ideally under supervision. Work on a non-flammable surface in a ventilated area away from living spaces. Wear safety glasses, use insulated tools, follow the facility’s battery incident response plan, and never leave a pack charging unattended.

This chapter explains how professionals approach a build, so you understand what good work looks like. It is an overview, not a substitute for hands-on training.

Tools you'll need

Digital multimeter and an internal-resistance (IR) tester
A cell capacity tester or a smart charger with a discharge test
Capacitive or transformer spot welder (never a soldering iron directly on cells)
Pure nickel or copper-nickel strip sized for your current, insulating rings (fish paper), cell holders, Kapton tape, PVC heat-shrink
BMS, main fuse, rated wires and connectors, insulated tools, safety glasses and gloves

The professional build sequence

Source genuine cells from one batch. Get the datasheet and invoice. Mixing brands, ages or batches causes imbalance.
Test and grade every cell. Record voltage, internal resistance and (for critical builds) capacity. Reject outliers and group cells with closely matched values.
Bring all cells to the same voltage before joining parallel groups. Otherwise large currents rush between cells.
Plan the layout. Use holders, check polarity twice, and add insulating rings on the positive ends of cylindrical cells.
Spot-weld the connections. Size the strip for the current each group carries. Short, firm welds are fine; heat from soldering damages cells.
Wire the BMS balance leads in the correct order, following the BMS manual exactly. Measure each lead's voltage before you plug the connector in.
Protect and enclose. Add a fuse on the main positive, insulation layers, padding, strain relief and an enclosure with a suitable IP rating.
Test before use. Check pack voltage and insulation, do the first charge at low current while watching group voltages, then load-test and confirm the BMS cut-offs work.
Label and log. Note the configuration, chemistry, date, cell batch and test results.

Road use is regulatedA battery fitted to a road-registered vehicle in India must meet type-approval safety standards (see Chapter 9). Home-built packs are for learning, bench projects, prototypes and off-road use. Commercial packs are built and certified by approved manufacturers.

Want to build and test a real pack with expert guidance? DIYguru's hands-on battery training covers cell grading, spot welding, BMS wiring and pack testing.

See battery courses

Chapter 8

Battery health for EV owners: make your battery last longer

Activity 06 · Make a care plan

A better routine starts with the manual

Use this checklist for your own vehicle. It is a learning aid, not a safety inspection or approval to charge a damaged battery.

I know the manufacturer’s approved charger and charging temperature limits.
My charging area is ventilated and does not block an exit.
I follow the vehicle’s storage and state-of-charge recommendations.
I know how to contact authorised service if range, temperature or battery behaviour changes.

0 of 4 care habits reviewed.

Heat is the biggest enemy of lithium-ion batteries in India. Good habits can add years to a pack's life.

Everyday habits that help

Let it cool before charging. After a ride, follow the manufacturer’s charging-temperature guidance; a fixed waiting time does not prove that the pack has cooled.
Park in the shade and keep the charger in a ventilated spot, not in direct sun.
Avoid sitting at 0% or at 100% for long periods. For daily use, NMC batteries are happiest between about 20% and 80–90%. LFP is more tolerant of full charges, and an occasional charge to 100% helps the BMS recalibrate its gauge.
Storing the vehicle for weeks? Follow the manufacturer’s storage SoC and inspection interval; check periodically rather than automatically topping it up.
Use the original or a matched charger. A wrong-voltage charger can overcharge the pack.
Limit fast charging when you don't need it, and charge where a fire would not block an exit.

Warning signs: stop and get it checked

What you notice	Likely cause	What to do
Sudden big drop in range	Weak cell group or BMS imbalance	Get a diagnostic scan; ask for group voltages
Battery % jumps or drops suddenly	SoC estimate drift, or a weak group hitting cut-off early	Follow the OEM diagnostic advice; do not attempt a full charge if damage, overheating or a fault is suspected
Pack is warm while parked	Internal fault or failing cell	Stop use and charging. Keep people away and contact authorised service; do not handle a hot or suspect pack
Swelling, hissing, sweet or chemical smell, smoke	Cell damage or thermal event starting	Do not charge or ride. Keep away, move people out, call emergency services if there's smoke
Water entered the battery area	Seal or IP failure	Don't charge. Get it inspected before use

Most EV battery warranties are defined by years, kilometres and a minimum State of Health. Read the fine print for your model and keep your service records.

Chapter 9

EV battery safety standards and rules in India

India tightened battery rules after the 2022 wave of e-scooter fires. Here's what anyone working with EV batteries should know.

AIS-156 and AIS-038: type-approval safety

After fire incidents involving several electric two-wheeler brands in 2022, the Ministry of Road Transport and Highways (MoRTH) amended AIS-156 (for L-category vehicles, i.e. two- and three-wheelers and quadricycles) and AIS-038 Rev. 2 (for M and N categories, i.e. cars, buses and goods vehicles). The amendments added requirements for battery cells, the BMS, on-board chargers, pack design, and thermal propagation from an internal cell short circuit. They were implemented in two phases, from 1 December 2022 and 31 March 2023.

BIS performance standards

The Bureau of Indian Standards (BIS) also notified performance standards for EV traction batteries in 2022. Together with AIS-156 and AIS-038, these define how packs sold in India are tested.

Battery Aadhaar (Battery Pack Aadhaar Number, BPAN)

In January 2026, draft guidelines proposed a Battery Pack Aadhaar system to trace every battery across its life:

Each pack gets a unique 21-character ID, marked on the pack as text and a QR code.
It holds static data (manufacturer, specifications, material composition, carbon footprint) and dynamic data on the battery's condition and usage, uploaded to a government portal.
It covers EV batteries in L, M and N vehicle categories and industrial batteries above 2 kWh.
Producers and importers are responsible for assigning the ID and uploading data. The system is also meant to support the PLI scheme for Advanced Chemistry Cells and future recycling rules.

These were draft guidelines at the time of writing. Check the latest MoRTH notifications for final requirements and timelines.

Battery Waste Management Rules, 2022

These rules use Extended Producer Responsibility (EPR): battery producers must arrange collection and recycling. As a user or workshop, never dump lithium-ion batteries in regular waste. Hand them to an authorised collector or recycler.

Chapter 10

Careers in EV batteries: roles, skills and how to start

Quick reference

Find a battery term

Search the glossary

Ampere-hours measure charge capacity, not energy by themselves. Multiply nominal V by Ah to estimate Wh.

Watt-hours measure energy. 1 kWh equals 1,000 Wh.

C-rate

Current relative to rated capacity: 1C for a 5 Ah cell is 5 A.

SoC

State of charge estimates how much usable charge remains now.

SoH

State of health describes ageing relative to a defined baseline; capacity and resistance are common indicators.

BMS

Battery management system: monitors the pack and controls protection within its design limits.

Series

Connecting groups in series adds their voltages.

Parallel

Identical cells in parallel share voltage and add capacity.

Thermal runaway

A self-accelerating heat-generating failure that can lead to fire and hazardous gases.

Cell balancing

Managing state-of-charge differences between series groups; it cannot repair a damaged cell.

10 terms

Battery skills are among the most in-demand skills in India's EV industry, from the workshop floor to the R&D lab.

India's EV battery demand is projected to grow from 17.7 GWh in 2025 to 256.3 GWh by 2032 (Customized Energy Solutions).
EV sales in India crossed 2.5 million units in 2025, led by 1.5 million two-wheelers and 0.7 million three-wheelers (IESA).
Adecco India estimates the EV sector could create 30–40 million jobs by 2030, and says battery recycling grew at a 55% CAGR between FY22 and FY26.

Role	What you do	Typical background	Where to start
EV battery service technician	Diagnose packs, read BMS data, replace modules, handle HV safely	ITI, diploma, 12th + automotive experience	CEVT program
Pack assembly / production technician	Cell grading, welding, BMS wiring, end-of-line testing	ITI, diploma	CEVT program
Battery testing & validation engineer	Run cycle, abuse and thermal tests; check standards compliance	B.E./B.Tech (EEE, ECE, Mech)	Battery & BMS Advanced Nanodegree
Battery pack design engineer	Size packs, design thermal and mechanical layout, select cells	B.E./B.Tech (Mech, EEE, Auto)	Battery & BMS Advanced Nanodegree
BMS hardware / firmware engineer	Design BMS boards, write SoC/SoH algorithms, CAN integration	B.E./B.Tech (ECE, EEE, CSE)	Battery & BMS Nanodegree, or the PG Program
EV systems engineer	Integrate battery, powertrain and embedded controls in a vehicle	Graduates and working engineers	PG Program in EV & Embedded Systems

Turn battery knowledge into an EV career

Talk to a DIYguru EV career advisor. We'll help you choose between CEVT, the Battery & BMS Nanodegree and the PG Program, and share batch dates, fees and EMI options.

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