Phased said:

As EV's are battery storage systems, how does this stack up when there are two vehicles with a total of 140 kwh of storage in the same garage?

A fair question ... Other countries have also selected, through some of their national standards, to consider similar limits.

The debate on this is not short.

Phased said:

A neighbour of mine has such in an integral garage with a questionable 1 hour fire rated separation from their timber framed house. 

Depending what happens in the battery fire ... which in turn depends on the specific batteries involved. Some lithium batteries (but not all) might exhibit jet-like flames which get through the 1 hour fire separation in 10 minutes.

Given the house is wooden framed, what does the insurer recommend (or what will they accept) would perhaps be a more pertinent point?

Phased said:

As EV's are battery storage systems, how does this stack up when there are two vehicles with a total of 140 kwh of storage in the same garage?

A fair question ... Other countries have also selected, through some of their national standards, to consider similar limits.

The debate on this is not short.

Phased said:

A neighbour of mine has such in an integral garage with a questionable 1 hour fire rated separation from their timber framed house. 

Depending what happens in the battery fire ... which in turn depends on the specific batteries involved. Some lithium batteries (but not all) might exhibit jet-like flames which get through the 1 hour fire separation in 10 minutes.

Given the house is wooden framed, what does the insurer recommend (or what will they accept) would perhaps be a more pertinent point?