Li-Po Battery 340 mAh

I’m doing some experiments with a MKR WAN 1310 and a MKR ENV shield with an SD card. In the tech specs of MKR WAN 1310 it’s written: “Supported Batteries - rechargeable Li-Ion, or Li-Po, 1024 mAh minimum capacity”.

For testing I do not need a large battery and I have a 340 mAh Li-Po battery.
a) I assume that I can use this battery?
b) Can I use the built in battery charger for this small battery?

Thank you for your advice.
Zeno

Then charge the battery on a suitable charger and then use it for testing.

If the MKR 1310 is to charge that, then it had to buy a battery of at least 1024mAh.

The price difference between a 340mAh and a larger battery isn't that huge.