You can get Outdoor 20W Manual Hand Crank Generator for $41.29 with coupon (from Banggood). Go down and check coupons out. Remember to check price history if it is available. Best price?
15V/1.3A Size 19.5x 8x 17cm/7.68x 3.15x 6.69inch Weight Approx.270g, Max power 20W Rotating speed 2000rmp/min Voltage/Current: 3V/6.6A, 12V/1.6A, 5V/4A, 6V/3.3A, 9V/2.2A
Latest coupon code price check (UTC time):
Banggood ($41.29)
Banggood warehouse is located in China. There are no active coupons for this product, but the price is pretty low isn’t it? Is it cheap? Hmmm, price is higher than average (which is $27.39 right now), so better set price alert down below…
Link: Banggood product page
Price: $41.29
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): 59e292, e7afa2, aff7off, 502C6B, f383d7, AFfbG10, BGIPRee12, BGVDay10%off, BGCP24, BGCP3343, BGCP363, bGhOnEy10, 21322a, BGIPR8, f4fab6, BGODFN1, BGEUOD1, BGZPBC15, BGTY704CP, BGCuponation10, BGTY503DL, BGHONEY2110, BG10OFFAFF, BGwhielabel, BG022e68, BGc2d7a9, BG0b82e2, 13f142, BG10OFFAFF1, BG4d9120, BGAlerabatod, BG1336d3, 00c906, BG00c906, BG49dc65, BGe46870, BG7280ff, Tabby20, BGc8c272, BG36e006, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, BG2bb7a1, BG8ReviTrage, Cuponation9, BG26848f, BG073996, BGc363fd
(probably won’t work, but you can try them out)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for Outdoor 20W Manual Hand Crank Generator.
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)).