Google product feed error – value too long in attribute: id

All my products are being rejected by Google products with the message – value too long in attribute:id – the limit is 50 characters. e.g. https://www.completeessentialoils.com/products-page/skin-care/peppermint-cocoa-lip-balm-100-natural-therapeutic/
this is one of the values wp-ecommerce is generating for id for this product. It is the entire url for the product. Attempts to set g:id in metadata in wp-ecommerce result in the same failure and an additional one – too many attribute values for attribute: id

https://www.ads-software.com/plugins/wp-e-commerce/