I got a Victron Blue Power charger 12/20 for a AGM batterie 125 Ah. I put the charger in the "high" mode for a 14,7 V charge. I noticed that the voltage in de storage fase in still 13,5 V. This is higher than the specifications tell (iq 13,2 V) Can it be caused by the lower temperature (+/- 5 degree Celcius)