$26.99 – Size: 8.5x4x1.7cm, Material: Lipo.
You can get URUAV 7.4V 2700mAh 40C RC Battery T Plug for $26.99 with coupon (from Banggood). Just check coupons out (with price alert and history). Let’s see what best price is ATM.
Latest coupon and price update (UTC):
Banggood ($26.99)
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it? Isn’t it too expensive? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $15.99)
Link: Banggood product page
Price: $26.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG863d1b, BGToys8, BGMatt2022, BG589b2e
(these codes were not working in latest coupon update, but you can check them out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Do you need price history chart (for all/most countries) for URUAV 7.4V 2700mAh 40C RC Battery T Plug? There we go. The lowest price was: $13.99.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).