I am trying to power my tx2 developer kit with a 19V 3A Energizer Battery.
This one: https://www.amazon.com/gp/product/B00CFHBV5E/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=jetsonhacks-20&linkId=742d68a8c62560871078692c849c869e
I connect the battery to the TX2 via the DC port and get the the CR5 light to become solid red. However when I press the power button the J2 light blinks once and dies. I measured the voltage of the output of the battery and is 19.34V. What is interesting is that the battery can hook up to a power supply to charge the battery and act as a voltage regulator and in this case, with the same connection to the Nvidia, it can power it on.
I have several ideas on what the issue might be. 1) Battery is not providing enough current to boot the TX2. 2) The Energizer battery is a smart battery and automatically provides correct voltage. Initial unbooted voltage might be less than 19V and when it boots the voltage changes and the TX2 has a safety built it preventing it from booting. 3) Somethings is just wrong with the battery and I need a new one but it seems to hold charge well (20000mah) and power other lower voltage devices perfectly.
Does anyone have any experiences with this or have any suggestions?
The URL indicates a 5V, 2.1A charger…if that charges another battery that’s ok…if that is the actual power unit, then it isn’t capable of providing sufficient power (it isn’t 3A, and it is only 5V). If boosted to a minimum voltage, then even less than 2.1A would be available. Is is correct that you are only using the device at that URL for charging?
Typically people have had issues when the very short spike of current required right at the moment of starting is not sufficient (during that short spike voltage is not stable). Even low gauge wires or long wire runs could do this. In some cases a seemingly “standard” 5.5 mm barrel connector is not actually standard, and the inner diameter may have insufficient contact for some uses. Here is an example, look at the listing of “actual diameter” where it can be either 2.5 mm or 2.1 mm despite all being a “standard” 5.5 mm barrel connector:
Having a large capacitor as close as possible to the Jetson will sometimes help.
So here’s the update. The Nvidia works fine. I tested this by using power supply and providing about 14V. I double checked this voltage using multimeter. The Tx2 booted no problem. I then checked the voltage of my battery, 19.3V. Should boot on but it doesn’t. This led me to conclude that the battery has some constant voltage circuitry which means the current drops as the battery dies and is unable to provide power to the TX2.
I guess the takeaway is so stay away from Energizer batteries or rechargeable batteries intended to charge phones and laptops. A safer thing is probably just regular lipo batteries and just introducing a shutoff mode in the TX2 when it detects the voltage is getting low.
My guess is the actual problem is that the battery is “too smart” and something it does while turning on the power interferes with what the TX2 wants to draw from the power source, and the battery kicks in some kind of protection. (Or the TX2 decides the power is not stable, and protects itself.)
Did you try with a really large capacitor at the input to the TX2? 33,000 uF or more? (Or course, the initial draw of that capacitor may be so bit that it, itself, triggers the battery problem… could be worthwhile investigating.)
Also, you should hook up a scope on the battery output, and see what it looks like when you’re trying to turn on the board.