I recently got a T208 UPS HAT for my Jetson Orin Nano (super developer kit), but it performs unexpectedly. Via jumper, I set AON active. I have 4 batteries installed, and a 5V DC adapter plugged in. On pressing the power on button, I see the PWR LED on (green);
and PLD LED on (red); Then both go off, and 1 LED on the battery gauge indicator goes on briefly, then off. Needless to say that the Jetson does not start. Obviously the PLD indicator is showing why the unit does not start. I Thinking I had too little battery charge, I left the DC plugged in overnight. An attempt to start it failed in the same way. My only guess is that the power adapter is not sufficient, however it ran the Jetson ok, when I used it before I got the T208 HAT. Any thoughts appreciated.
I got a new DC adapter which, according to battery gauge LEDs, charged the batteries fully. Now, on pressing power button, the PWR LED on the T208 goes on. The PLD LED remains off, but Jetson does not start. Battery gauge LEDs remain on.
The Jetson Orin Nano devkit (even the “super” one) can draw up to 5A or more at 5V during boot or heavy workloads.Many UPS HATs (including the T208) are designed for Raspberry Pi loads (≤3A). If the HAT’s boost circuitry cannot supply the current the Orin demands, the board will fail to start — exactly like you’re seeing. What’s the rated maximum current output of the T208 on its 5V rail? If it’s <5A, that’s likely the root issue.
According to various sources, including Core Electronics, maximum output current of T208 is 8A. I believe that a 16850 battery can supply 2A. I’ve currently got 4 batteries installed, hence could provide 8A, in my understanding. I haven’t got all possible 6 in place ATM, because the battery holder for 2 is between the boards, when assembled. I’d normally rather not disassemble the device to change batteries. It sounds like I need to in this attempt to test run from battery. A difficulty in assembly was that the super carrier board and T208 do not align mounting holes well. This also means that the 10 pins from UPS board to the GPIO pins break-out don’t align well. I’ve managed to connect the 2 boards anyway, but it’s not ideal. Maybe I need different hardware.
Regards, Lee.
Hi Lee
To work this out you MUST convert to Watts.
The Jetson can require 5A @ 5V. this equates to 25W.
Your battery is 3.7V nominal
25W @ 3.7V = 6.76A
Allowing for 85% conversion factor (probable worst case) means your 3.7V battery supply will have to provide 7.95A.
Just a little bit more than your estimate.
I might add here that most power banks quote capacity mAhr at the BATTERY (3.7V) NOT at 5V output. Looks better that way. In fairness most reputable brands DO state that on the product even if it is in the fine print.
Cheers Bob
Thanks Bob. I understand your point, in principle. I would like to check the numbers, because I’m confused. For a 3.7V battery to supply 25W means current is approximately 6.76A, as you say, or more ,based on conversion factor, as you say. The documentation says that the T208 can supply more (max 5.1V 8A = approx. 40W), which would be sufficient. Anyway, I figure something must be missing (like Amps) in DC-DC transformation, so I added 2 batteries, making it the full 6. Battery gauge shows full charge, but press power button on T208 shows PWR LED briefly, and Jetson doesn’t start.
One reason to convert to watts for calculations. The T208 may be able to supply 40W BUT you cannot get out more that what you put in. That is an unfortunate fact.
So to get 40W out you must put in 40W plus any losses. Conversion factor is sometimes quoted at 85% which seems to be worst case. That means on this basis you have to input (40W/85) * 100=47W. At 3.7V this is 12.7A.
Unfortunately it is not a “point in principle”. It is a fact and there is nothing can be done about it. The power has to come from somewhere and if the somewhere is a 3.7V battery that is a it.
Better conversion factors will yield a better result but it is marginal so I always work in worst case figures.
Sorry to put any sort of dampener on your thoughts but there s no point being nice about it and having a failure down stream because all the points were not considered.
Cheers Bob
Add on.
6 batteries should be enough to at least power something. So there is something else wrong. As we don’t have your set up to play with you will have to do some sleuthing
Firstly are all the voltages present and correct. Measure the current being drawn in case there is a short or something in the system. If you measure the current with a DMM do so on the 10A (or 20A with my DMM) range to avoid voltage burden problems. Re check your wiring.
Hi Lee
Just having a look at what you have
Is this it
SKU: DFR0865
If so where does “T208” come from. When I googled this I got all sorts of things like bearings etc but nothing that vaguely resembles a UPS hat.
Cheers Bob
I did notice this device has 4 X 2 pin connectors down one edge.1 X 5V IN and 3 X 5V OUT.
AND THEY ARE ALL THE SAME.
I wonder what genius thought that one up.
Hi Bob. I believe I got it from you guys. https://core-electronics.com.au/ups-hat-for-jetson-nano.html
I will have to check my invoices.
Regards, Lee.
Hi Lee..
Firstly I am not a Core employee. Only a Forum contributor.
I did a bit of between the lines sleuthing to come up with that product.
That did not answer the question
I can’t find any reference to this number anywhere in the product description but in old age it is possible my eyes are playing tricks.
I am just interested in how you came to call this device “T208”. Things will be a lot clearer on this side of the fence if you could be more accurate and quote the Core SKU number as it makes finding details much easier.
Cheers Bob
Sorry Bob. My bad regarding your role. I refer to the device as “T208” because that’s printed on the PCB that links the nano board, and the battery board (using 10 pins). I thought I saw it somewhere in documentation, but now unsure where. The other evidence I can find ATM is the core-electronics product page includes reference to " T208 components" The SKU is DFR0865. Geekworm list it as “Geekworm T208”
Regards, Lee.
Hi Lee
Found it
- Mounting holes and standoffs provide mechanical stability of Jetson Nano and T208 components
Looks like part of mounting or interfacing bits. NT the UPS proper.
Cheers Bob
A quick thought.
You are not holding the button down too long are you. I think if you did it would turn off again.
- The onboard button can control the power on/off (short press the button-turn on, press and hold the button for at least 3 seconds-turn off)
Hi Rob. Thanks for the time you must have spent to see that
misalignment. I noticed it during assembly that it was not ideal.
Especially where one corner does not have a mounting through-hole, so
I’m letting it sit on a nylon standoff with screw in one end only. It
keeps the boards apart at a consistent distance, but is not ideal. The
alignment of the 10 pins between developer board and T208 was also not
great. It’s in, but makes me concerned about stability. On the power
button subject, I am familiar with expected functionality. I think my
approach needs to be sourcing another UPS, or a carrier board with
mounting capability to suit the T208. Maybe I will create a separate
forum topic.
Hi Lee
I haven’t actually seen that misalignment. I find it surprising that the 10 pin connector is supposedly misaligned. There is only so much you can do with a 2.54mm pin spacing and it looks pretty standard to me.
You have not provided any detail about this bit and I am not sure what plugs into what. As I said I googled “T208” and got nothing relevant. So to comment you would have to provide good pics or more detail. At least what a T208 is.
I am very surprised that misalignment is as bad as you make out or if it exists at all. This depends on your definition of “misalignment” . Mounting holes, 10 pin connector position or actual pin pitch (2.54 vs 2.5 or 2mm or something like that). Being concerned re instability due to this is a bit of a worry. I would carefully re visit this area as it could be the cause of your problem.
Like have you accidentally connected the 10 pin connector “mirror image” so having incorrect connections, that wouldn’t help much. That 10 pin header does not appear to be keyed so the polarity or orientation is not controlled.
Cheers Bob
Hi Bob. As I previously mentioned, I refer to the device as “T208” because that’s printed on the PCB that links the nano board, and the battery board (using 10 pins). I thought I saw it somewhere in documentation, but now unsure where. The other evidence I can find ATM is the core-electronics product page includes reference to " T208 components" The SKU is DFR0865. Geekworm list it as “Geekworm T208”. Just google that. Anyway, I am abandoning the T208 setup because of the apparent difficulty. I’ve ordered a SmallRig Mini 50Wh 14.8V battery module. Thanks for your help.
Regards Lee.
Hi Lee
Yes I looked at that Geekworm page. A bit of confusion with different vendors quoting differently for the same part. Personally I would see that T208 as being the number for that small interface par, not the whole thing. But as I say different vendors.
Getting to your problem. I don’t see how that 10 pin connector is misaligned. The connections are quite long and should have been moved slightly to fit. Is it connected to the correct pins on the Jetson. The functions are marked on the UPS as they probably marked on the Jetson. Something like an incorrect connection here (especially the power pins) could well be your problem. Seems a pity to abandon what is probably an expensive exercise if it is a simple thing like that.
Cheers Bob
PS You still have to charge that battery and convert to 5V. Your present set up already has charging facilities built in.
