Can I use the iPod 6th gen battery on the iPod 7th gen?

They appear to be different voltages. They may be inter compatible, but I doubt it, and I really wouldn’t suggest testing it out

"I have taken apart my iPod 7 and compared its battery to what iFix is selling here for the iPod 6 and it seems to be the same battery except for a larger connection glue tab and a different number on the lead 1740 for the one in the 7gen vs. 1524 on the 6gen. The solder points appear to be the same.

The voltages are the same…

I am going to purchase the 6gen battery and put it in my 7gen and report back here if it implodes or works :)"

i do have an iPod but i had to replace the battery I only had an iPod 6 battery and it works.

if the battery fits, it might work but there might be differences in the capacities and charging rates between the two batteries. this differences may contribute to safety issues.