A month ago, my Hugo's batteries died and it could not be turned on at the time. I ordered these from Mercateo (http://www.mercateo.co.uk/p/2794E-615(2d)2472/ENIX_Energies_3_75V_Rechargeable_Lithium_Battery_Pack_2200mAh.html?redirectedFrom=rsmgl2811), and replaced them by myself. So far, My Hugo has works with no problem at all. Hope this helps Hugo users in the future.
Best regards,
Siriusg