Help with trickle charge please

Help please guys.  I thought it a good idea to put a Motobatt charger on a Motobatt battery on the rally bike to maintain it between rides.

The KTM seems to not like it!  See attached clip when I leave it on. 

[youtube]https://youtu.be/HSKXTGavl_Q[/youtube]

It seems to feed the current back into the bike intermittently.  Any suggestions of how to avoid this without disconnecting one of the terminals?