Rechargeable Battery Box 8878

[750ACE]

Quick question... What is the recharge time for the 8878 Lipo Battery Box? The reason I ask, I would like to purchase 2 Battery Boxes and only 1 AC adapter. I rather not spend $50 worth of AC adapters if the charge time is quick. Bad enough 2 battery boxes costs $49 each + tax, from Lego direct.

[Zerobricks]

First charge some 4 hours, the usual charge time later is arround 2 hours.