Two unpublished documents reviewed by Reuters, marked "Production plan 2024", show Northvolt has since early September been consistently missing weekly production goals for shippable cells, or cells deemed good enough to be delivered to clients. They include data as recent as the week ending Nov. 10.

The documents show, along with goals for each week, a target to reach 51,000 deliverable cells in one week by the end of 2024.

Contacted by Reuters, Northvolt said the targets had been set on Sept. 5 and were "long out of date". It did not elaborate on its current production targets, which it said are based on contracted customer deliveries.

Hailed as Europe's best chance to weaken China's overwhelming dominance of the electric vehicle (EV) battery market, Northvolt fired a fifth of its global workforce and shrank its operations in September to stay afloat. The Swedish company, led by former Tesla executive Peter Carlsson, has yet to make a profit.

Northvolt has been discussing the possibility of filing for Chapter 11 bankruptcy protection in the United States, two sources familiar with the matter told Reuters on Nov. 15. The company declined to comment on the possibility of a Chapter 11 filing.

Hobbled by delays in deliveries and struggling to produce sufficient volumes of high-quality batteries, Northvolt lost a 2 billion euro ($2.1 billion) contract from BMW (BMWG.DE) in June.

A Reuters review of internal production sheets, other company documents, and conversations with four company sources indicate Northvolt continues to face challenges in boosting production levels for battery cells, the units that store and convert chemical energy into electricity.

For example, in the week starting Oct. 21, the company delivered just 22,000 cells deemed shippable against a target of 30,000, the documents, which listed weekly goals until the year-end, show. In the week ending Nov. 10, there were "more than 20,000 shippable cells", the company told Reuters.

Such production levels contrast with a goal of 100,000 cells per week by year end that the company disclosed to Reuters on Sept. 24 and earlier to employees under its "Path to 100k" roadmap for quality cells.

In response to questions for this story, the battery maker said it did not plan to meet the goal, which it defined as 'informal', this year, the first time it has officially stated this.

"The plan is currently under review based on the execution of our strategic review, which has influence on the way we operate our main facility Northvolt Ett," Northvolt said.

The company publicly launched the strategic review in July and started to publish its results as of Sept. 9. Key actions undertaken as part of the review included adjustments to customer orders and reduction in shift patterns.

"This is a very challenging industry," Northvolt said in response to a Reuters query on production issues.

"However, we have made great progress through this year, to the point that today we are consistently, week-on-week producing high-performance cells for our customers."

Northvolt said in September it had tripled its cell manufacturing levels since the start of the year.

Weekly production sheets reviewed by Reuters show the company has assembled more than 51,000 good cells per week only once between the end of August and early November. In the week ending Nov. 10, the last week Reuters has data for, it assembled around 26,000.

Cells assembled go through further production steps and quality checks, a process that can reduce the number of cells deemed ready for clients.

The battery-maker was occasionally able to meet internal weekly goals at earlier stages of the cell manufacturing process, other documents reviewed by Reuters show.

The company sources, who declined to be named because they are not authorised to speak to media, said Northvolt's problems in ramping up output stemmed from faults with machines, inexperienced staff and unrealistic ambitions.

Northvolt said it disagreed with such characterisation.

"For machines that are in serial production, we have very good levels of performance," the company told Reuters.

"Naturally, following installation we have a period of commissioning, during which machines are fine-tuned and calibrated," the company said. It added that its staff was the most experienced among all Europe-based battery manufacturers.

Battery experts say production levels can fluctuate on a weekly basis. Making cells is a delicate process and doing so at scale is widely acknowledged by experts as a big challenge for any battery maker.

Despite its problems, Northvolt remains ahead of other European battery makers, industry experts say.

PRODUCTION SLOWDOWN

Production at one of the two manufacturing buildings in its Skelleftea plant was suspended in late October, two of the four Northvolt sources said, adding the stoppage was expected to last at least until December.

To cut costs, the company ended its 24/7 production cycle on Nov. 11 and started to manufacture only on weekdays, according to the four Northvolt sources and documents seen by Reuters.

Northvolt confirmed to Reuters the reduced shifts, adding it was "running fewer production lines than previously, and focusing on delivering on contracted customer volumes."

Slowing down production can improve the quality of cells, Hans Eric Melin, founder of consultancy group Circular Energy Storage (CES), that tracks recycling data in the lithium-ion battery market, said. It allows for more efficient repair and maintenance, according to three of the Northvolt sources.

Following BMW's order cancellation, Northvolt has primarily produced cells for truckmaker Scania and luxury car makers Audi and Porsche, brands belonging to its largest shareholder Volkswagen (VOWG_p.DE).

Scania said in September it has been receiving Northvolt cells on schedule and in sufficient numbers after agreeing a new delivery plan. Last year, the truckmaker was unable to ship electric trucks to clients due to Northvolt's problems.

"Beginning of this calendar year, we made a new handshake with them where we had to realise they were not capable of ramping up to the speed that the market was requesting," Scania CEO Christian Levin told Reuters last week.

($1 = 0.9487 euros)