Rick,
From a BCR point of view, proceed as follows:
- Any non-PS3 engine without a battery charging port is either a PS1 or 5 volt PS2, and takes an 8.4 volt BCR.
- Any engine with a round battery charging port is a 5 volt PS2, and akes an 8.4 volt BCR.
- Any engine with a 2-pin, somewhat rectangular battery charging port is 3 volt PS2, and takes a 2.4 volt BCR2.
PS3 engines already have a super capacitor and do not require a BCR at all.