Not sure if i get what you mean correctly…Are you saying the voltage level of TX1 does not match that of turtlebot or the battery capacity of turtlebot is too small for TX1 + bot?
For the former, the input voltage level range of TX1 module is 5.5V~19.6V, if the battery output can’t reach 5.5V, a boost DC/DC is necessary. For the latter, a bigger or multi battery could work. :)
If you are concerned about current draw at peak, then the Turtlebot could possibly be used to charge a battery capable of higher current output (versus Turtlebot) for a short time…which then powers the Jetson.
Peak power could be an issue, but I don’t know, you’d have to try it out. Consider that part of the power rating for Jetsons includes devices powered over the USB bus, the M.2 slot, and the PCIe (even HDMI has a tiny power requirement when it powers the monitor’s I2C to query EDID). If you have nothing powered over those external device slots, then you might get away with that as average power…and I would think that for nothing more than keyboard and mouse 2A would be more than adequate on average. The idea of putting a battery in and powering the Jetson by battery while the other device charges the battery is to give you an enormous peak current delivery capability compared to 2A.