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53

12v 5v 変換

Worth a look

Shows low returns (0.6%), but pricing outside the sweet spot ($829.99 avg) keeps it on the watch list.

Market size 54Growth 17Conversion 50Competition 58Returns 97Price range 0Avg price 0Brand share 65Review moat 95Quality gap 79

Returns

Incredible0.6%

return rate — above 5% kills the launch gate

Review moat

Great100.14

avg incumbent reviews — the moat a new listing must climb

Quality gap

Great4.2★

avg incumbent rating — lower means beatable quality

Brand share

Good66%

top-5 brand share — brands hold most of the demand

Competition

Good50%

top-5 click share — leaders hold, buyers still browse

Market size

Good¥366K

¥366K/yr · 11K searches

Conversion

Okay4.0%

search→purchase rate — share of searches ending in a sale

Growth

Bad-16.3%

90-day search growth — must beat 0% to launch

Avg price

Bad¥829.99

avg listing price — sweet spot $15–$100

Price range

Bad¥436.17–¥1551.18

cheapest to priciest tracked listing — scored on the share inside $15–$100

According to Flapen's Amazon Japan niche tracking, 12v 5v 変換 is a ¥366K/yr Amazon Japan market (11K searches/yr). The top 5 brands hold 66% of demand. Demand peaks in Aug. Verdict: Worth a look — 53/100.

Data updated Jul 31, 2026 · scored weekly · How we score niches

12v 5v 変換 market data

Units sold / yr
250–500
avg 0–100/product
Revenue / yr
¥207K–¥415K
units × avg price
Conversion rate
4.0%
Avg BSR
#401
Page quality
0%
Prime
100%
Sponsored
95%
Out of stock
6.4%
Avg brand age
46 months
Avg seller age
201 days

Competition & brand share

The top 5 products take 50% of clicks — established leaders, but buyers still shop beyond them.

Brands

17 falling

Sellers

36

Top-5 brand share

66%

Top 20: 100%

Top-5 click share

50%

Top 20: 97%

Open market

28%

  • DROK29%
  • Zakata12%
  • ノーブランド品9%
  • エーモン(amon)8%
  • YABOANG8%
  • uxcell6%

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — -16.3% search growth over the last 90 days.
450350Holiday '24Spike '25Black Friday '25Spike '26SepDecMarJunAugNovMarMay

Peak months: Aug · busiest ÷ quietest = 1.6×

Top 12v 5v 変換 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%4%¥15K8%¥29K12%¥44K16%¥59K1101001K10K Reviews — right = deep review moat Market share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 22 tracked products in this niche — three views at once, no toggling.

What buyers say about 12v 5v 変換

What buyers praise and complain about, mined from review topics.

What buyers love

使用の容易さ11%

“問題なく使えます。”

コストパフォーマンス11%

“安くおすすめです”

総合品質9%

“耐久性:少し熱を持ちますが問題ないレベルです。安定しています。”

耐久性8%

“半年使用してますが動作OKです。”

コンパクトさ7%

“コンパクトで良い、. アンペアはどこまで出てるか測ってないが. Amazonスティックの電源供給は出来た。”

組み立て/インストール5%

“取り付けも簡単に出来ました。”

広告と実際の製品の違い5%

“書いてある通りの能力でした。”

コネクタ/ポート/プラグ4%

“2口のコネクタは重宝します”

水に強い4%

“金属筐体で防水処理もされておりネジ固定用の出っ張りも付いていますので屋外でバッテリーから5Vを取り出したいシステムには丁度良いです。”

バッテリーの内蔵3%

“魚探のバッテリー用に使っています、問題なく使えます”

What buyers complain about

総合品質15%

“ゴミ”

サイズ全体11%

“小型”

充電8%

“通電せず使えなかった。”

コネクタ/ポート/プラグ7%

“USBにも繋がりません。”

加熱6%

“密封されていることを考えると発熱は少ないのでしょう。”

耐久性6%

“あっという間に”壊れた””

接続性 - 全体3%

“USBにも繋がりません。”

組み立て/インストール3%

“現在取付進行中です。”

燃料効率3%

“不燃ごみ行き”

不良材料/部品3%

“前回購入分が調子よかったので追加注文したら全く出力されない不良品だった。”

Top return reasons

サイズ全体17%
接続性 - 全体13%
充電12%
不良材料/部品11%
総合品質10%
互換性-全体10%
機能全体10%
コネクタ/ポート/プラグ8%
広告と実際の製品の違い4%
環境に優しい2%

Common questions

Is 12v 5v 変換 profitable to sell on Amazon Japan?
The niche generates ¥366K/yr across 22 tracked products. 1 of 2 products launched in the last 360 days are still selling. 90-day search growth is -16.3%. Flapen's verdict: Worth a look (53/100).
How competitive is the 12v 5v 変換 niche?
17 brands and 36 sellers compete. The top 5 products take 50% of clicks and top 5 brands hold 66% of demand.
What do buyers complain about in 12v 5v 変換?
Top complaints mined from reviews: 総合品質, サイズ全体, 充電. The return rate is 0.6%.
When does demand for 12v 5v 変換 peak?
Demand peaks in Aug; the busiest month runs 1.6× the quietest.
What does it cost to enter the 12v 5v 変換 niche?
Listings span ¥436.17–¥1551.18; the average listing price is ¥829.99 (sweet spot $15–$100). The average incumbent carries 100 reviews — the moat a new listing must climb.