I’ve been using a lithium ion battery I bought from Amazon with my CK88 and it’s been awesome - I’m getting 5-6 hours out of a single charge. FYI if you end up trying one of these they also make models with USB charging ports as well (wish I’d seen those before I bought mine - will probably upgrade to the bigger capacity one with usb one day).
Anyways did a review if you want to check it out
Anyways did a review if you want to check it out