Electric bus batteries in Chile: testing, repair and end of life

The 2028–2029 decision window

Santiago’s first electric bus cohorts arrived between 2017 and 2019 under lease and maintenance contracts that included the battery. When those contracts end, the operator faces a decision that until now belonged to the supplier: what to do with a pack that no longer performs like new but is nowhere near scrap.

Our estimate, built on the publicly documented 2017–2019 cohorts, is that the first meaningful batch is around 200 buses of 324 kWh: roughly 65 MWh of lithium iron phosphate, equivalent to between 500 and 650 metric tons of packs, concentrated in 2028 and 2029. This is an Ecobaterías estimate, not a reported fleet figure: we publish it with its range because depot logistics are planned years ahead, not months.

The practical point is simple. A bus pack weighs hundreds of kilos, counts as hazardous waste until proven otherwise, and does not fit the household collection flow. A decision taken on the day the bus leaves service is a decision taken badly.

Status of each service line

Status reviewed on September 18, 2026. The pilot program works with limited batches and case-by-case lead times: we do not commit industrial capacity on lines that are not yet in full operation.

Fleet testing protocol

Testing is done by batch and starts at the depot, so the fleet is immobilized no longer than necessary.

1. Inventory and BMS readout. Serial number, chemistry, charge history, fault codes and recorded temperatures for each pack.
2. Electrical test. A controlled capacity cycle and internal resistance measurement to obtain the real state of health, not the one the management system declares.
3. Module spread. Measured module by module: a healthy pack with two weak modules behaves like a sick pack.
4. Thermal and cooling review. Thermography under load and inspection of the cooling circuit, the origin of a large share of field faults.
5. Classification and certificate. Each pack is assigned a route and receives a state-of-health certificate by serial number.
6. Batch plan. The full set of results becomes the plan: what returns to the fleet, what is repaired, what moves to second life and what goes to recycling.

Swipe to see the full table

Source: Ecobaterías testing protocol · 2026-09-18. These times describe laboratory capacity and are not a contractual turnaround commitment.

What fails in an LFP bus pack, and what gets repaired

Buses running in Chile mostly use lithium iron phosphate cells, a stable chemistry that tolerates deep cycling. In practice the pack rarely dies as a whole: what shows up are unbalanced modules, degraded connections, temperature sensors out of range and cooling circuit faults. The breakdown of failure modes and of what can be repaired lives on our lithium battery testing and repair page; we do not duplicate it here.

What changes on a bus is scale and logistics: the pack does not travel in a box, the vehicle cannot sit idle indefinitely, and any intervention has to be documented for the contracting authority. That is why we work in batches, within windows agreed in writing before we start.

The four decision routes

Each pack is assigned to one of four routes according to its measured state of health. The thresholds are Ecobaterías’ own, not a standard, and they are applied identically across our operation.

Source: Ecobaterías testing protocol · 2026-09-18. Reference methods: IEC 63330-1 and UL 1974, cited as reference standards and never as our own certification.

Second life for bus modules

A bus module that no longer serves traction is still a lithium iron phosphate module with thousands of cycles left in a less demanding duty. Second life is not “reusing leftovers”: it requires selecting modules by capacity and internal resistance, matching them, assembling them in a cabinet with its own management system, and testing the assembly again.

Chile’s draft battery decree also gives it regulatory weight: it proposes that at least 30% of the lithium-ion valorization target be met through preparation for reuse. It is a text under consultation, not a standing obligation, but it shows where the requirement is heading.

Recycling at our own plant, with a certificate

Whatever does not return to the fleet and cannot serve a second life goes to our Santiago plant, which operates with a sanitary authorization from the Seremi de Salud (Chile’s regional health authority) of the Santiago Metropolitan Region for the hydrometallurgical process. The pack is discharged and dismantled, casing, wiring and electronics are separated, and the active fraction is processed until the minerals are recovered.

That is the same circuit that produced the cobalt sulfate successfully tested at Codelco’s El Teniente hydrometallurgical plant, with trials from November 2023 and results published in July 2024: 22% lower cost and 40% lower consumption than imported sulfate, with one daily addition instead of three. The El Rancagüino press report does not name the supplier; the documentation showing that it is Ecobaterías is available under a confidentiality agreement.

When a batch closes we issue the valorization certificate and the transport traceability record, which is what gets reported afterwards.

Obligations for a bus depot

Today a removed pack is hazardous waste and is handled under Supreme Decree (DS) 148/2003: authorized storage, transport with a manifest, and an authorized final destination. Chile’s Extended Producer Responsibility law (Ley REP, Law No. 20,920) is in force as a framework, but the decree that sets targets for batteries is still a draft.

That draft, published with Resolution 821/2026 of the Ministry of the Environment, proposes three things that bear directly on a depot:

• Vehicle workshops would be required to hand removed batteries to the collective management system (Art. 29).
• Storage installations above 1 MWh would have to report every year, before May 31, through the RETC single window (Art. 40).
• Lithium-ion targets would start with no requirement for the first two years, rise to 15% in the third and reach 50% from the tenth, with at least 30% met through preparation for reuse (Art. 22).

The Ministry’s deadline to propose the decree was extended to January 29, 2027 by Resolution 4,225/2026. None of this is enforceable yet: we write it in the conditional on purpose.

Source: draft battery decree, Chilean Ministry of the Environment · 2026-09-18.

How the service is contracted

The service is contracted by bus batch or by pack, within the 2026–2027 pilot program of our testing line and with slots agreed case by case. Before work starts we agree in writing on scope (which testing level, how many packs, in which window), who moves the packs and what documentation is delivered at closing. Assessment and decision are two separate steps: first we measure, then we decide, and the report stays with the operator whether or not they continue with us.

Frequently asked questions

Sources