So, I'm actually looking for the opposite as above. I have an Omicron, but want to use the cheaper carts, therefore I need a m601 batt to 510 cart. I have searched, but the only ones I have found are around 10 bucks. I looked at the above links but found nothing that I saw would work. I know I can get them from PV, but at 10 bucks plus shipping I'd like to find a cheaper source?