Jetson tx2 powered using battery

Hey,
I would like to power my Jetson tx2 board using a battery. Primary application would be making an autonomous turtlebot using realsense. I want the jetson to run for at least an hour on a single charge. I googled and found that a 3S LiPo battery (12V 5A) would work, but I think it won’t last long on a single charge. Can someone please clarify a few of my questions :

  1. I read that if the battery gets discharged it may affect the jetson. is it so?
    2)Can I use the in-built battery on turtlebot? How long will that work? considering the fact that it powers the bot also.
  2. Is there any other battery or power source available that i can use?
  3. The power of 12V 5A battery is 60 W. Is it enough to power Jetson? Since, the Rating on jetson is 19V 5A.
  4. what can be the consequence of connecting a battery and getting it discharged after sometime
  5. how long will it run? (LiPo 12V 5A battery 2000mAh)
  6. If I over-power or under-power the board. Will it get damaged? (yes, but I would like to know the threshold)

Hi,

First I think you need to check the AppNote for design request of battery and charger: https://developer.nvidia.com/embedded/dlc/tx1-tx2-module-battery-charger-design-guide

As for power consumption and working time, that depends on the workload of your application and the battery capacity. You can calculate them with DC power supply first and then choose fit battery.

95lakshay,

Do you plan to just use only the TX2 module in yout turtle bot, or are you also using a carrier board?

I am researching options right now to power both the TX2 module and the carrier board that come in the TX2 Developer kit.

I will post my progress on this thread - can you please do the same?

Thanks,

The carrier board works with 12V input.
The Jetson draws between 3W and 15W depending on how hard you work it.
This translates to about 0.5-1.0 A at a 12V input.

With a 5Ah 12V battery, you could expect the battery to last 5 hours with a reasonable workload (more if you’re just idle, perhaps slightly less if you use lots of peripherals and work the CPU and GPU hard.)

It might be able to use the Turtlebot battery. Obviously, the runtime will depend on how big the battery is, and how much current you draw from it, which depends on how hard you work the circuitry and the motors.

You can do the runtime math quite easily – figure out how many watts each thing is using, and divide the battery capacity in watt-hours into that number. Subtract 20% for inefficiency and margin.

So, if you have a 100W motor, and run it at a 20% duty cycle, and use 10W from the Jetson, and 5W from other electronics, you will have an average draw of (100W20% + 10W + 5W) == 35W. If you have a 12V / 5Ah battery rated at 55 Wh, then you should expect to be able to run for (55Wh/35W80%) == 1.25 hours, or about 75 minutes.

The main thing to watch out for is to make sure the input voltage is well filtered.
If the TurtleBot runs the motors straight from the same battery, then it’s quite possible that the motor controller PWM and motor commutation will generate significant EMI on the 12V battery rail.

I’ve found the Jetson motherboard to not be particularly happy about quickly changing voltages, so you might want to put a big fat filter on the power input to make it stable.
Parts in my parts box include a 6 A rated 220 uH inductor, and a 33000 uF 25V rated capacitor, which together make a great filter. (Battery -> inductor in series -> capacitor in parallel -> power input for Jetson.)

You may be able to get away with much less, or put an inline DC/DC converter in the way to re-condition the voltage.

Snarky,

How are you connecting the battery pack to the Carrier board? I don’t see any pins on the board - just the connector for the power supply that ships with the dev kit.

Thanks!
Chris

The round connector is a standard barrel connector; just splice your own cable or buy a pre-made pigtail.

Snarky,

Can I connect an external 12V battery directly to the carrier board without using a filter. Since, I am not using the same battery for turtlebot and Jetson tx2.
Just wanted to make sure before making any connections. Also, is there an internal circuit in tx2 which can prevent the board from getting fried in case the battery gets discharged.

Thanks!
Lakshay

Hello , can anyone tell me how whats the power dissiation of tegra tx2

Hi, it is 7.5W (Max-Q) / 15W (Max-P), please check the module datasheet in DLC, and also you can search the related topics in forum.

We are trying to power TX2 using 14.8V,20000mAh LiPo battery.We tried large filter using 3300uF capacitor.Still it is not working.Can we directly connect LiPo to TX2 without any filter?