Tech Nerds-think this battery setup will work for Transcend Micro?

[johnbrain]

Using my Transcend Micro in my Sprinter off the inverter really drains my house batteries and there isn't a 12V DC adapter available for it. I may have shopped differently had I factored in 12V use but it works great in hotels around the world. The limited battery options are very expensive or not compact or both.

Running this by you.

The Transcend Micro Poweraway battery outputs as follows: 

• Rated Output:  DC 14.8V, 2.7A
  

Would a 14V USB-C to Barrel trigger cable (currently marketed for the Transcend Micro) running off a 24000mAh Anker PD battery with following specs work even for just a few hours? Charging the battery isn't an issue

USB-C1= 9V ⎓ 3A / 15V ⎓ 3A / 20V ⎓ 3.25A / 3.3V~16V ⎓3A

Comment from one of the really expensive CPAP battery backup makers.

"Q: Is the DC output port a fully functional usb-c pd port? In other words can it provide voltages between 5 and 24 volts depending on the cable used?

A: Yes, it is. But please be advised that the DC out port is only designed to provide power on CPAP/BiPAP Machines. You may consider using the USB out port to power or charge other devices"

Thanks in advance. Really trying to solve this riddle without spending a lot for a singular use item.

[BoxcarPete]

Confirm the voltage of the battery pack for runtime. mAh is only half of the equation required to determine total energy storage. That in turn is only half of the equation for runtime since we don't know the power draw of your machine (it's probably variable based on pressure, etc). If the cable is OE kit for that machine, and the input end is according to the USB-C standard, then you should have some flexibility of what kind of battery you plug into.

[johnbrain]

Confirm the voltage of the battery pack for runtime. mAh is only half of the equation required to determine total energy storage. That in turn is only half of the equation for runtime since we don't know the power draw of your machine (it's probably variable based on pressure, etc). If the cable is OE kit for that machine, and the input end is according to the USB-C standard, then you should have some flexibility of what kind of battery you plug into.

Yeah need to brush up on my battery math. First goal is to even determine if it'll run as you obersved it seems it should. The cable isn't OE but it's the cable marketed with the Freedom V2 battery for the Transcend Micro and sold by many CPAP suppliers.
The battery pack voltage is variable if I am reading the specs correct. I figure I'll solve the runtime riddle after I solve thewill-it-run-at-all riddle.

Maybe you can discern more from this

USB-C1=  9V ⎓ 3A / 15V ⎓ 3A / 20V ⎓ 3.25A / 3.3V~16V ⎓3A

USB-C2: 5V ⎓ 3A / 12V ⎓ 1.5A

Total Max Output via USBC: 65W & If using both at the same time (45W+20W)

USB-A Output：5V ⎓ 3A / 9V ⎓ 2A / 10V ⎓ 2.25A / 12V ⎓ 1.5A

Total Max Output：22.5W

ps here's the very limited specs of the battery Transcend Markets for the Micro. 5200 mAh?
Integrated Battery:Transcend PowerAway P8 Battery: 14.4 VDC, 5,200 mAH

[BoxcarPete]

Yep, the voltage is variable, as USB-C is set up to do. However, mAh is meaningless without the voltage it is supplied at. A disingenuous battery manufacturer could claim millions of mAh and bury it in the fine print that it's only capable of that output at a voltage level of 1 mV or something. Since the voltage is variable we can start with the assumption that it is supplied at the lowest output level of 5V, which would ballpark us around 120 Wh of power, which would run a CPAP taking 30-60W for 2-4 hours, which is not all that long compared to how long you would want to sleep. If I'm wrong and the amp-hour rating is for the battery pack internal voltage, runtime is going to be significantly longer than that, but you need to try and get the V number directly associated with the mAh number, they must declare it for the rating to be valid.

[johnbrain]

I'll see if I can get it. I also came to the conclusion it'll run longer. As you mention so much depends on breath rate, pressure etc. I. The absence of their specified voltage rate I may just have to Amazon the battery and try it. Seems the CPAP should at least run, just don't know how long.

IF draw was a constant, and it's not, I think I can get 7 hours out of. 24400 battery. Which is fine by me.

Clearly you know more than I. OE states their ac charger outputs at 18v vdc 1.67 amps. But OE batteries OUTPUT at lower voltage. So...who knows? I ran their math which supports their 2-day claim at 40w ac (doubt it's true)

Thanks for the assistance I really appreciate it.

[BoxcarPete]

Little digging shows that the OE battery is 71 Wh, which is good because that's a benchmark for real power storage. The one you propose is 24 Ah at some unknown voltage, which is likely somewhere around 5V (lowest rated output), or maybe even 3.7 which is the nominal voltage of a Li-Ion battery cell. I got to that conclusion from another product from the same company which listed a 27650 mAh battery pack at 99 Wh. That gives us a total power storage similar to the OE battery, likely a little higher. If they're claiming multiple nights from a single charge then the machine is drawing a lot less than 30W under normal operation.

[johnbrain]

Thanks I really appreciate it and how you shared with me getting closer to apples tomapples with wH. Pretty confident it'll work so I'm going to order the battery. At worst it cost me a little time and $2 for the Freedom USB-C cable  The Freedom battery is listed as 100 wh but it's a lot larger and more expensive. If my math is correct the Anker is around 88.

[johnbrain]

... If they're claiming multiple nights from a single charge then the machine is drawing a lot less than 30W under normal operation.

While not the utmost in clarification the manufacturer informed me it draws 4-7 watts on battery power.

[johnbrain]

Manufacturer informed me the TM has am operating range of 14.4-19v and runs at 14.76 on their battery

[johnbrain]

Well. Didn't work. Hmm.