RFID antenna close to LIPO battery

[igeorge]

Hello,
I have a very small ABS box.
I am forced to put my LIPO battery under the PCB and under it the RFID antenna for 125KHz reader.
It is like a sandwich.
Bottom of the box, RFID rectangle wire antenna, LIPO battery, and in the top the PCB.
I wonder if the LIPO which is covered by aluminum foil and a protective plastic above will interfere with my RFID antenna and reduce reading distance.
Please help.
Thank you

 

[FvM]

I wonder if the LIPO which is covered by aluminum foil and a protective plastic above will interfere with my RFID antenna and reduce reading distance.

Yes it does. Worst case, a ferrite plate may be placed between RFID coil and battery for isolation, the coil circuit must be possibly retuned.

 

[igeorge]

Now, next scenario

Top of the box
LIPO
0.5 inch (1.27 centimetres) free space
PCB
0.250 inch (0.64 cm) free space
RFID antenna
Bottom of box

What is your opinion.
Regarding RFID card, I will just touch the bottom of the box, so maximum distance 0.4 inch (1.02 cm).

 

[FvM]

We had to look at the PCB details, e.g. if it involves continuous planes. The overall behaviour is hard to predict, probably simpler to to empirical tests.

 

[igeorge]

Thank you very much.
When I get the parts(the battery) I will try, and update you.