Honda admits that it is at a loss to explain the battery issue that has plagued Lance Stroll in recent races.

In Mexico the Canadian was forced to retire after just 6 laps in order to "avoid damaging the battery", while a week later at Interlagos he suffered two further battery-related issues, retiring from the race after 38 laps.

Unfortunately, Honda doesn't understand the issue and may not discover the root cause for some time.

"At the moment, we know what happened, but we don't know what is the root cause," admitted the Japanese manufacturer's trackside general manager and chief engineer, Shintaro Orihara.

"We will check the data and also we will check the battery," he added, "it may take a few weeks to find the root cause.

"From the data we need to find some countermeasure for next year and also we need find the actual root cause of this error for next year, otherwise we keep having the same issue, so this is quite important for us to understand what is the root cause."

The initial engine upgrade appeared to be a step in the right direction, especially considering the reliability issues in the first half of the season. But since the introduction of the second (ADUO) upgrade there has been a clear step backwards.

"In the middle of season our reliability was better," said Orihara, "but the last two or three races we had several issues, some not relating to mileage or just pushing, but recently especially battery issue.

"At this moment it's difficult to say relating to mileage or operation point, so first we need to understand what is the root cause."

The start of the Mexico weekend looked good for teammate Fernando Alonso, but as the weekend progressed performance fell away, while the conditions in Brazil allowed the Spaniard to deliver his best qualifying performance of the season. However, just a few laps into the race it was clear that the two-time world champion could not match the pace of his rivals and he dropped down the order.

"Wet condition hide our weakness of engine performance and also some short deployment," admitted Orihara, "but driveability is going to be quite important in wet conditions.

"We need to improve the drivability we found in this race and also qualifying," he added, "in some areas we see some positive things, but still we found the loop which should improve for next race and also next year."

Thus far, the Honda pair have completed just 68.3% of the season's racing laps, seeing the chequered flag 19 times form 40 starts, Stroll having suffered 13 DNFs, only one due to an accident.

Despite Aston Martin's patience, the situation cannot be helped by the fact that Honda's new boss comes from an HR background.