I recently ordered a spare AC-CDI for my Zongshen from AliExpess:
https://www.aliexpress.com/item/1923...27424c4dPlkxiK
Just be careful when selecting the "color", order the AC-CDI unit. The DC-CDI might work with some minor rewiring, from what I saw in spud's stickies, but there's no report of anyone actually trying it.