# I want to know if it's possible to connect Jetson TX2 with Lipo battery(Zippy 3000)

I want to connect Jetson TX2 with Lipo battery(Zippy 3000)

Robot that I made with Jetson is:
– 19.5V, 4.62A
(but I don’t know about it’s impedence and allowable current.
Maybe it’s same with TX2’s impedence and allowable current)

then, can I connect this Lipo battery?(Zippy 3000):
– 18.5V, 3000mAh, 20C

In my opinion, Voltage needs more power(about 20V)
and Ampere is upto TX2’s impedence and allowable current
(According to mAh=A/C, 3000mAh=A/20C, so current=60A(maximum output))
is TX2’s allowable current need to be under 60A?

As you can find in module datasheet, the Imax of VDD_IN is 3A for VDDmax(19V). If you want to modify them, please refer to this doc : https://developer.nvidia.com/embedded/dlc/jetson-tx1-tx2-voltage-current-config

But I checked the Tx2’s adaptor, and it said 19.5V and 4.62A
Which one is right information?(19V 3A or 19.5V 4.62A)

Adapter has tolerance for use case, 19V 3A is the request of module.

then, is it ok to understand it as a minimum value?

For better understanding, please check the doc I just gave the link of. The input power limit (EDP) is 40W, you can calculate the corresponding voltage and current accordingly.

The recommended range is 5.5V~19.6V as you can see in table 59.

The battery is ok for TX2 module, while seems you misunderstand the output current of battery. The output current depends on the workload of TX2 module, it is impossible to reach 60A with 18.5V.

doesn’t it have guard circuit? Because some devices can control the input voltage.
(output of concent power is 220v, but device allows only few that they need)
So I want to know if it controls the voltage by itself without adjusting the power.

I’m a little confused…Where’s this 220V from? Aren’t you going to use battery? If you use an adapter, it will convert AC 220V to a constant DC output (19V or other value), and TX2 will convert 19V to voltage that system needs, such as 5V, 3.3V, 1.8V etc.

@jaimo1213 - You are using a couple of terms in a non traditional manner which others might find confusing.

Power in an electric circuit is calculated by multiplying the voltage in “volts” by the current in “amps”. This answer is expressed in “watts”. Consequently, you can calculate any one of the three if you know the other two.

Impedance is a measure of electrical resistance, I don’t understand how you are using it in this discussion.

When you state

This is confusing. The voltage input to the TX2 can be between 5.5V~19.6V. 20V is over that, so it does not sound like a good idea. Since voltage is not a measure of power, I think you can see where it’s confusing.

Your Zippy nominally delivers 18.5V, which means that it is a 5 cell battery. Typical 5 cell batteries have an operating range of 16V to 21V as the cells go from fully charged to drained. 21V > 19.6V, which will cause damage to the Jetson. Obviously you can use a step-down regulator/buck converter to fix this problem if you must use this battery. However, typically people use a 3S or 4S LiPo with the Jetson if they are using this type of battery.

So if you want to do it without using a voltage regulator, a 4S LiPO (4 cell / 14.8V nominal / 16.8V charged) is probably the sweet spot. You can also use a 3S LiPO without regulator (11.1V nominal / 12.6V charged / 9V discharged). However 5S LiPO’s, although 18.5V nominally, are ~21V fully charged, so that will cause damage. You can also use other battery chemistries of course that match the needs.

The Jetson has built in power converters and such so it can power things such as the USB ports at 5V from the provided input.

Also, the DC jack is 2.5mm x 5mm which is useful if you’re trying to figure out how to connect with it. As always, you should have a way to monitor the the voltage level of a raw LiPo battery like this so you don’t over discharge it. If you discharge it past about 3.0V per cell, it may be effectively be dead.