I recomend this product for powering seeed 3.7v products… you may need to make a custom pig tail for the connector to the device… also it seems the polarity on seeed devices is backwards from “STANDARD”
I think they are good… comes in a multi pack with charger and from Amazon. But i think any battery of this form will be fine if you do not have access to amazon or other places… it has just worked for me. Be sure the conector and polarity will work… no need to pay extra for correct polarity connectors because most of the time you going to replace the connector, or may be able to swap the pins in the connector, but do not let the wires short!