Air Carrier Captain reported improperly documented Lithium Ion battery powered wheelchair during preflight. Captain summoned the ramp manager who corrected both improper gate check procedures and cargo weight errors.

Narrative

After blocking out I was beginning to load the takeoff performance into the FMS when I saw the load report remarks showing motor wheelchair lithium [powered] and motor wheelchair non-spillable. I went back to the cargo page and noticed there was no cargo weight included; only bags. I asked the ramp if they had sent numbers including the wheelchair weight and they said they did not include any weight for a motorized wheelchair. They then had to reopen the cargo bin to look at the wheelchair and realized it was not properly tagged; and only had the gate claim tag. They had to call a ramp manager to help complete the proper documents. Confused by why; the remark looked as if there were actually 2 wheelchairs checked as cargo. I verbally confirmed there was actually only one motorized wheelchair with a non-spillable battery. After about 20 minutes ramp advised it was all straightened out and sent updated cargo load report numbers with 70 pounds added for the wheelchair weight. Ramp needs to verify the accuracy of their load report prior to sending their numbers. Also paperwork for the wheelchair should have been verified before putting it into the cargo bin. The load remarks appearing to have 2 different wheelchairs is also confusing.