Hi all, about 5 years ago, I bought the full Sonus SFX range. It I tried it wasn't amazed. It went onto the shelf and I honestly forgot about until I moved recently. Recently I thought I'd revisit it. i wondered what the Shelf Life was for this range. The bottles are nearly all full, I have given them a shake and they seem ok. The SFX4 that is polycharged was my main concern.. would it still be ok to use?