My experience with the battery issue was nothing but bad. I put BCRs in my engines and stopped buying MTH engines. That was before the green battery. I did buy 1 engine(RK CP Royal Hudson) that had the new flat blue battery and it did work much better than the old type. However I replaced that one as well with a BCR. I have had no further battery issues with my 6 MTH engines since tossing the batteries.
Jim