Copper Bus Bar

Tin-Coated Copper Busbars for EV & ESS Battery Packs in India

By Arambhika · 3 October 2026 · 5 min read

Tin-coated copper busbar 20 x 2 mm for prismatic battery cells

India is moving fast to lithium for solar storage, telecom backup, inverter banks and electric three-wheelers. Many of these packs use large prismatic LFP cells, and those cells are joined with bolted copper busbars, not welded nickel strip. This guide explains why copper, why tin coating, and how to size the bar for your current.

Why copper for busbars?

Among common metals, copper conducts best after silver. For the same cross-section a copper bar runs cooler than aluminium, which matters when a pack carries tens of amps for hours. Large prismatic cells, such as the 100 Ah LFP cells common in Indian ESS and e-rickshaw packs, are connected through bolted terminals, and a flat copper bar is the standard link.

Why tin coating?

Bare copper tarnishes over time, and a tarnished joint has higher resistance and heats up. A tin coating protects the surface, helps in humid and coastal air, and keeps bolted joints stable. Our Universal copper busbars are 20 mm wide and 2 mm thick, tin coated, in four lengths.

Where Indian builders use them

Solar and home energy storage: LFP rack and wall-mount batteries paired with hybrid inverters.
Inverter battery banks: lithium replacements for tubular lead-acid batteries in homes and shops.
Telecom and data-centre backup: compact lithium banks replacing lead-acid in towers and server rooms.
E-rickshaws and electric three-wheelers: prismatic LFP packs with high daily cycling.
Battery swapping and fleet packs: repeatable assemblies that need uniform busbars.

Choosing the length

Pick the length by the distance between the two cell terminals you are joining, with a little allowance for the bolt holes. We stock four lengths in the same 20 x 2 mm section: 55, 60, 68 and 82 mm. Measure your terminal pitch before you order, or send us a drawing for a custom size.

Size	Cross-section	Listing
55 x 20 x 2 mm	40 mm²	View product
60 x 20 x 2 mm	40 mm²	View product
68 x 20 x 2 mm	40 mm²	View product
82 x 20 x 2 mm	40 mm²	View product

A simple way to size a busbar

Cross-section is width times thickness: 20 mm x 2 mm gives 40 mm². A common rule of thumb for bare copper busbars in open air is roughly 1.2 to 1.5 A per mm² for continuous duty, which puts a 20 x 2 mm bar in the region of 50 to 60 A. Treat that as a starting point only. Derate for an enclosed pack, high ambient temperature (think summer in Rajasthan or Gujarat) and the quality of the bolted joint. For higher current, use a wider or thicker bar, or two bars in parallel. See our copper busbar sizing guide for more.

Assembly tips

Clean flat contact faces. Dust or oil raises joint resistance.
Use the right bolt and washer set and tighten to the cell maker's torque. A loose joint heats up; an over-tight one can damage the terminal.
Re-check torque after the first heat cycles.
Insulate exposed bars to prevent accidental shorts.

Building a small cylindrical-cell pack instead? Read our pure nickel strip and plated strip guides.

General guidance only. Validate busbar size, torque and pack safety against your own design, the cell maker's data sheet and the standards that apply to your product.

Copper busbars in our store

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Frequently asked questions

What size copper busbar do I need for a 100 Ah LFP cell pack?

It depends on your continuous current, not the cell capacity alone. As a rough start, a 20 x 2 mm bar (40 mm²) suits tens of amps; for higher current use a larger section or parallel bars. Send us your pack current and we will advise.

Why is the busbar tin coated?

Tin protects the copper from tarnishing, which keeps joint resistance low and stable, especially in humid and coastal Indian conditions.

Do you make custom length copper busbars?

Yes. Send your terminal spacing, width, thickness and quantity, and we will quote a custom busbar.

Is copper better than aluminium for battery busbars?

Copper conducts better, so a copper bar of the same section runs cooler. Aluminium is lighter and cheaper but needs a larger section and careful joint treatment.

Do you supply copper busbars across India?

Yes, from Noida with GST invoice. If a size shows as out of stock, tap Notify Me and we will confirm availability on WhatsApp.