In the life-time of the Prophet, Abu Talha did not fast because of the Jihad, but after the Prophet ﷺ died I never saw him without fasting except on ʿId-ul-Fitr and ʿId-ul-Aclha.
كَانَ أَبُو طَلْحَةَ لاَ يَصُومُ عَلَى عَهْدِ النَّبِيِّ ﷺ مِنْ أَجْلِ الْغَزْوِ فَلَمَّا قُبِضَ النَّبِيُّ ﷺ لَمْ أَرَهُ مُفْطِرًا إِلاَّ يَوْمَ فِطْرٍ أَوْ أَضْحَى