I have an electrical equipment which is connected to the power supply via an adapter which specifications are:

INPUT: 100-240Vac, 50-60Hz
DC OUTPUT: 24V, 3.125A (75W max)

I would like to use a battery instead.

I have found a battery which specifications are:

26400mAh capacity. 
Maximum Output: 24V Port: 2.5A; USB Port 2.1A

I don't really know how to read this spec. (especially the "Port: 2.5A" part).

My questions are:

  1. Do you think that the battery is compatible with the equipment?
  2. What parameters should I consider to select the appropriate battery for a given equipment?
  3. What parameters shall I consider to prevent the equipment from being damaged?
  4. What are the important parameters on the equipment side? Voltage + Intensity + ???
  5. What are the important parameters on the battery side? Capacity + Voltage + ???

These questions may be a bit redundant: it's because I'm not sure what the right question is...

Thank you for your help and best regards.


This would be the equipment (this is a printer, see the paragraph "electrical specifications"):


This would be the battery:


  • 1
    \$\begingroup\$ You are missing the following information in order to answer #1. a) how much power is being consumed by the equipment? b) how long does it need to be powered for? \$\endgroup\$ Jun 20, 2017 at 18:37
  • \$\begingroup\$ A battery pack almost never provides a steady voltage throughout discharge. What is beeing described sounds more like a portable power source with internal regulation (sort of a higher power analog of a "USB power bank") but that's not explicitly stated. \$\endgroup\$ Jun 20, 2017 at 19:19
  • \$\begingroup\$ You are mis-parsing the spec. It should be read as "24V Port:", not just "Port:". From the description, I would assume that it has two output connectors, one for 24 Volts, and one for USB. \$\endgroup\$ Jun 20, 2017 at 19:37
  • \$\begingroup\$ A battery voltage drops in use, and rises when charging. So, it is unclear that the battery will be a constant 24V. The "24V" specification is NOMINAL, and the range of variation might be important. \$\endgroup\$
    – Whit3rd
    Jun 21, 2017 at 8:41

1 Answer 1


You have matched the voltage (24V) which is necessary to prevent damage to the equipment. However, the current provided by the battery pack may be too low. The AC adapter provides 3.125A while your pack only provides 2.5A. Since the supplied amperage must be greater then or equal to the amperage drawn, we don't really know how much is actually drawn by your equipment. If it actually draws <=2.5A, you should be ok. If it draws more, your battery pack will either:

  1. Shut down,
  2. Reduce the output voltage, which could damage the equipment, or
  3. Blow up, catch fire or similar if it's not well designed.

To be safe, you should select a battery pack which (a) provides the same voltage, and (b) provides at least as much current, as the adapter being replaced.

  • \$\begingroup\$ Hi, thank you for your answer. I complemented my question. If you could have a look at it, it would help me. Thanks. \$\endgroup\$ Jun 21, 2017 at 13:33
  • \$\begingroup\$ @LéaMassiot Unfortunately, the printer specifications do not provide any additional information about current draw. Given that 2.5 is significantly less than 3.125 and Zebra could have easily supplied a 2.5A adapter if that would have been sufficient, I wouldn't suggest trying this battery. You might try contacting Zebra to see if they can tell you the actual current draw. \$\endgroup\$
    – DoxyLover
    Jun 21, 2017 at 17:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.