Speculation regarding Class 379 future

[Energy]

But aren't the reliability issues with the 230 associated with the diesel engines? Battery electric units wouldn't have these.

Yes, I've heard the later 230 units are going to be using Caterpillar engines instead of the Ford ones to solve the reliability issue.
Battery EMUs should be fairly reliable as the electrical equipment wouldn't have changed much apart from the batteries added, especially as the electrostars / desiros are much younger than the D Stock.

 

[samuelmorris]

Yes, I've heard the later 230 units are going to be using Caterpillar engines instead of the Ford ones to solve the reliability issue.
Battery EMUs should be fairly reliable as the electrical equipment wouldn't have changed much apart from the batteries added, especially as the electrostars / desiros are much younger than the D Stock.

I've also heard rumours saying the opposite though.

You're right in that the primary defect with 230s is something the battery versions won't have, but there are certainly other issues going on and battery technology for rail use is very much in its infancy. Poorly-designed engine rafts or not, I think it's optimistic to assume that deploying technology seldom used in rail traction will be faultless, especially when most entirely conventional EMU deployments are also fraut with problems.