Issues with Plarail Steam Along Thomas

Ok, so he makes steam now, but I didn't realize I needed distilled water, so I used purified bottled water. Now, he seems to be producing less steam and, in the times when he comes to a stop and lets off a large burst of steam, it seems to be the case that the steam comes out weakly for the majority of the time, then a strong burst at the end. I have put fresh new batteries in, but that leads me to a tangental question about Tomy / Plarail / Trackmaster engines in general: what are the best batteries to put in the engines and how is the best way to keep them running at full capacity? Thomas is also making a louder-than-normal whining noise when he runs which I assume is an issue with lubrication in the powered Annie. Any help you guys can give is great- I want to keep this guy in the best shape possible.