---
title: "21700 Battery Charger — $183K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/automotive/21700-battery-charger"
last_updated: "2026-08-09T09:06:57.967Z"
locale: en
meta:
description: "Niche score 49/100 · $183K/yr market · 90K searches/yr · $30.94 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 49/100 · $183K/yr market · 90K searches/yr · $30.94 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "21700 Battery Charger — $183K/yr Amazon US Niche (2026) - Flapen"
---
# **21700 battery charger**
**Skip it**
Soft demand (-23.4% this quarter) — this niche doesn't clear our bar today.
Market size 37Growth 13Conversion 71Competition 36Returns 81Price range 90Avg price 95Brand share 27Review moat 72Quality gap 52
**Avg price**
**Incredible****$30.94**
avg listing price — sweet spot $15–$100
**Price range**
**Great****$9.82–$98.38**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Returns**
**Great****1.7%**
return rate — above 5% kills the launch gate
**Review moat**
**Good****610.36**
avg incumbent reviews — the moat a new listing must climb
**Conversion**
**Good****6.6%**
search→purchase rate — share of searches ending in a sale
**Quality gap**
**Good****4.4★**
avg incumbent rating — lower means beatable quality
**Market size**
**Okay****$183K**
$183K/yr · 90K searches
**Competition**
**Okay****63%**
top-5 click share — leaders hold, buyers still browse
**Brand share**
**Okay****89%**
top-5 brand share — brands hold most of the demand
**Growth**
**Bad****-23.4%**
90-day search growth — must beat 0% to launch
According to Flapen's Amazon United States niche tracking, 21700 battery charger is a $183K/yr Amazon United States market (90K searches/yr). The top 5 brands hold 89% of demand. Demand peaks in Jan–Dec. Verdict: Skip it — 49/100.
Data updated Jul 12, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **21700 battery charger market data**
- **Units sold / yr**
- **5K–6K**
- avg 100–250/product
- **Revenue / yr**
- **$155K–$186K**
- units × avg price
- **Conversion rate**
- **6.6%**
- **Avg BSR**
- **#45**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **88%**
- **Out of stock**
- **2.1%**
- **Avg brand age**
- **32 months**
- **Avg seller age**
- **204 days**
## **Competition & brand share**
The top 5 products take 63% of clicks — established leaders, but buyers still shop beyond them.
**Brands**
**11 **▲rising
**Sellers**
**16**
**Top-5 brand share**
**89%**
Top 20: 100%
**Top-5 click share**
**63%**
Top 20: 95%
**Open market**
**8%**
- Nitecore58% - Imren17% - FUGASUN7% - XTAR5% - EdisonBright3% - SUNLYTOUR2% - Open — no brand owns it (5 brands, 8%)
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -23.4% search growth over the last 90 days.
3K2KHoliday '24Spike '25Black Friday '25 seasonSepDecMarJunAugNovMarMay
Peak months: Jan, Dec · busiest ÷ quietest = 1.8×
[**Open Trend **](https://flapen.com/research/us/automotive/21700-battery-charger/trend)
## **Top 21700 battery charger search terms**
- **21700 battery charger**45K/yr-23.5%6.0% conv. - **nitecore charger**18K/yr-21.8%4.7% conv. - **nitecore battery charger**18K/yr-29.8%5.1% conv. - **21700 charger**7K/yr-24.4%5.7% conv. - **nitecore ums4**3K/yr+13.0%7.5% conv. [**All search terms **](https://flapen.com/research/us/automotive/21700-battery-charger/search-terms)
## **Top 21700 battery charger products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%5%$9K10%$18K15%$27K20%$37K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 24 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**IMREN 18650 Battery Charger 21700 Battery Charger for 3.7V 14500 10400 18500 18350 18650 18700 20700 21700 22650 26650 Li-ion Battery 1.2V Ni-MH/Ni-Cd Battery 4 Bay 18650 USB C Charger**Imren**$19.77**4.6★1,552 rev](https://www.amazon.com/dp/B094C6GDT2) [2**Nitecore UMS4 Intelligent USB-C Four Slot Quick Battery Charger for Li-Ion/Ni-MH/Ni-Cd/IMR 16340 14500 18650 21700 20700 AA AAA and More Batteries with Organizer**Nitecore**$38.28**4.5★1,233 rev](https://www.amazon.com/dp/B07JPL476H) [3**NITECORE UMS4 Intelligent QC 4-Slot Quick Battery Charger for Li-Ion/IMR/LiFePO4/Ni-MH/Ni-Cd 14500 16340 18350 18650 20700 21700 AA AAA with NITECORE Tag**Nitecore**$38.37**4.6★122 rev](https://www.amazon.com/dp/B07TX4TYYB) [4**NITECORE UMS2 Intelligent QC Dual-Slot Quick Battery Charger for Li-Ion/IMR/LiFePO4/Ni-MH/Ni-Cd 14500 16340 18350 18650 20700 21700 AA AAA with NITECORE Tag**Nitecore**$28.88**4.2★107 rev](https://www.amazon.com/dp/B0C77KK1HN) [5**21750 21700 Battery Charger LCD Intelligent 18650 Battery Charger for 20700 22700 26650 26700 16340 (RCR123) 17670 Rechargeable Battery with PCB Protection Board**FUGASUN**$13.58**4.5★3,869 rev](https://www.amazon.com/dp/B0B5V7VC2W)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**18650 Battery Charger 2 Bay LCD Display Universal Charger for 3.7V/3.6V Li-ion Batteries 26650 21700 18650 16340(RCR123) 14500 10400 1.2V Ni-MH/Ni-Cd AA AAA Batteries(Battery not Included)**MLKJHZ**$9.82**36 rev3mo ago](https://www.amazon.com/dp/B0GVBQ79HV) [**18650 Battery Charger for 3.7V/3.6V Li-ion Batteries 26650 18650 21700 14500 16340(RCR123) Ni-MH/Ni-Cd AA AAA C Batteries-Upgraded**TRAELY**$9.93**63 rev9mo ago](https://www.amazon.com/dp/B0FRFZGZW8) [**Nitecore NB Plus 10 000mAh Power Bank Ultra Lightweight and Slim USB-C and USB-A Ports for Phones iPads and More Travel Ready Fast Charging 5V/3A QC PD**Nitecore**$63.32**95 rev11mo ago](https://www.amazon.com/dp/B0FLT6TQ77) [**18650 Battery Charger LCD Display Charger for 3.7V Li-ion Battery 18650 26650 21700 18500 18350 16650 1.2V LiFePO4 Ni-MH Ni-Cd A AA AAA Rechargeable Batteries(Battery not Included)**Swanlake**$12.93**201 rev1y ago](https://www.amazon.com/dp/B0DN1CN8XQ) [**18650 Battery Charger MIEKLALE 8+2 Bays Smart Universal Battery Charger with LCD Display for Rechargeable Batteries Li-ion LiFePO4 RCR123 16340 26650 10440 14500 & 9V NiMH NiCd AAA AA(8+2Slots)**MIEKLALE**$39.09**193 rev1y ago](https://www.amazon.com/dp/B0DK79PHD9)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**18650 Battery Charger 2 Bay LCD Display Universal Charger for 3.7V/3.6V Li-ion Batteries 26650 21700 18650 16340(RCR123) 14500 10400 1.2V Ni-MH/Ni-Cd AA AAA Batteries(Battery not Included)**MLKJHZ**$9.82**4.3★**▲ 342%**](https://www.amazon.com/dp/B0GVBQ79HV) [**8 bays 21700 18650 Battery Charger XTAR New VC8 Plus 21700 Smart Charger with LCD Display 1A*8 Fast Charger for 3.6V 3.7V Li-ion 10440 18700 26650 1.2V Ni-MH AA AAA C Full Set with DC 12V 3A Adapter**XTAR**$44.65**4.3★**▲ 170%**](https://www.amazon.com/dp/B09H5K27JB) [**XTAR VC4SL Upgrade Version VC4S Smart Rechargeable Battery Charger Type C 4 Bay Fast 18650 Charger with LCD for 3.7V 3.6V Li-ion Battery 10440 14500 18650 21700 26650 and Ni-MH Ni-CD AA AAA**XTAR**$29.16**4.4★**▲ 147%**](https://www.amazon.com/dp/B09MT1ZSKL) [**18650 Battery Charger for 3.7V/3.6V Li-ion Batteries 26650 18650 21700 14500 16340(RCR123) Ni-MH/Ni-Cd AA AAA C Batteries-Upgraded**TRAELY**$9.93**4.6★**▲ 103%**](https://www.amazon.com/dp/B0FRFZGZW8) [**NITECORE UMS2 Intelligent QC Dual-Slot Quick Battery Charger for Li-Ion/IMR/LiFePO4/Ni-MH/Ni-Cd 14500 16340 18350 18650 20700 21700 AA AAA with NITECORE Tag**Nitecore**$28.88**4.2★**▲ 72%**](https://www.amazon.com/dp/B0C77KK1HN)
**~~View all trending →~~**
## **What buyers say about 21700 battery charger**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Charging**37%
*“Charges good”*
**Battery Life**13%
*“Long lasting under constant daily use”*
**Quality-Overall**10%
*“Build quality is excellent”*
**Advertised Vs Actual Product**6%
*“Just as advertised”*
**Value For Money**5%
*“Value for the money”*
**Ease Of Use**4%
*“Easy to use”*
**Weight Light**2%
*“much lighter than my other power bank”*
**Durability**2%
*“Long lasting under constant daily use”*
**Efficiency**1%
*“Works flawlessly”*
**Design-Overall**1%
*“Overall, the design appears compact and technically advanced on my desk”*
### **What buyers complain about **
**Charging**37%
*“Wont charge”*
**Durability**8%
*“Fails every few months”*
**Battery Life**6%
*“even though the battery is dead”*
**Quality-Overall**5%
*“Low quality”*
**Size-Overall**3%
*“Very small”*
**Advertised Vs Actual Product**3%
*“contrary to Product Information”*
**Functionality-Overall**3%
*“Did not work”*
**Compatibility-Overall**3%
*“AA and AAA don't fit”*
**Value For Money**2%
*“which is the one that I have has gone up $20 since I bought mine”*
**Instructions/User Manual/Troubleshooting**2%
*“I couldnt fully figure out how to use it”*
### **Top return reasons **
**Charging**50%
**Functionality-Overall**6%
**Weight Heavy**5%
**Advertised Vs Actual Product**5%
**Battery Inclusion**5%
**Size-Overall**5%
**Defective Material/Parts**3%
**Battery Life**3%
**Value For Money**3%
**Compatibility-Overall**2%
## **Common questions**
- **Is 21700 battery charger profitable to sell on Amazon United States?**
- The niche generates $183K/yr across 25 tracked products. 2 of 3 products launched in the last 360 days are still selling. 90-day search growth is -23.4%. Flapen's verdict: Skip it (49/100).
- **How competitive is the 21700 battery charger niche?**
- 11 brands and 16 sellers compete. The top 5 products take 63% of clicks and top 5 brands hold 89% of demand.
- **What do buyers complain about in 21700 battery charger?**
- Top complaints mined from reviews: Charging, Durability, Battery Life. The return rate is 1.7%.
- **When does demand for 21700 battery charger peak?**
- Demand peaks in Jan–Dec; the busiest month runs 1.8× the quietest.
- **What does it cost to enter the 21700 battery charger niche?**
- Listings span $9.82–$98.38; the average listing price is $30.94 (sweet spot $15–$100). The average incumbent carries 610 reviews — the moat a new listing must climb.
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