I'm in the market for batteries for my V911, and HCP100. Anyone willing to sell me theirs? Or point me in the right direction?

try amazon

https://www.amazon.in/Generic-WLtoys-Helicopter-Li-Poly-Battery/dp/B06XHX2KYC/ref=sr_1_11?s=kitchen&ie=UTF8&qid=1536241951&sr=1-11&keywords=v911

https://www.amazon.in/HITSAN-INCORPORATION-WLtoys-Battery-Charger/dp/B07GC66SR3/ref=sr_1_1?s=kitchen&ie=UTF8&qid=1536242007&sr=1-1&keywords=v911+battery

@kiran rc also selling small lipo battery.

http://www.rcindia.org/for-sale/3070mah-3-7v-lipo/msg292926/#msg292926

I don't know battery is for wltoys or not. So, buy after talking & getting full information.

The price on Amazon seems a bit too high... Besides, I'm sure it's some Chinese listing.

The batteries Kiran is selling are too small for this application. I need > 100 mAh for the V911, and preferably double that.

then take risk of money.
Order from AliExpress
https://www.aliexpress.com/item/3pcs-WLtoys-V911-F929-F939-RC-Helicopter-3-7V-200mAh-new-plug-1-25mm-Battery-For/32781812671.html.
US $10.15
Search on AliExpress else find manufacturer,retailer,seller on facebook then place order with PayPal.