Integration of a battery¶

We were told by Arnaud Glin that the optimal autonomy for the Microbox would be 3 hours (or more). Our first working plan included the purchase of a battery, but we abandoned this due to time and budget issue.
First, we wanted to buy a GoalZero battery. This battery has the advantage to be "plug and play" : upon receiving, we put it in the suitcase and case use it directly. It can provide 150 Wh, which is enough for our use.
But it is very expensive (229 $) and heavy (5.5 kg).