UBEC Failure

[BrianG]

I don't think a cap would be enough. If the BEC failed, the cap would just charge up to whatever voltage it was outputting. No, I think an added circuit that should shunt anything over 6.5v directly to ground would be better. This would blow an on board fuse or something like that. Yeah, the device would still be toast, but would save whatever expensive circuitry it was attached to.