Re: 40hp. electric tiller
It should be charging the battery when running, this model would provide 12-15 amps of charge power.
As to your "bundle of wires" - if they still all go into the connector they are most likely just the harness that you would use for remote operations (keyswitch, kill switch, wire for tach etc).
If they are just kinda hangin' out, perhaps a previous owner tried to jury rig something up which would mean "who knows" what you have there.
You obviously didn't have a Honda tech check it out for you upon purchase (well worth the cost when you buy any used motor, especially a 4 stroke), so at this point either a stop at a shop or the cost of an owners manual and maintenance manual from Honda is probably a good idea...