Sixteen products in nine months: Epico has 255 published reviews and knows which model overheats
CZ/SK market · October 2024 – June 2025 · mobile accessories, power banks, and chargers. Sixteen campaigns, five slots in each — and every approved review was published on at least three destinations.
Campaign results
80 reviews from 80 testers, each published on at least three destinations.
Every selected tester submitted a review across all sixteen campaigns.
Average rating of 9.06 out of 10; 96% of testers would recommend the product.
Twenty-five applicants per testing slot.
Each product in its own campaign with five slots.
Authentic content for further marketing use.
About the client
Epico is a mobile accessories brand — power banks, chargers, wireless stands, and protective gear. The portfolio refreshes quickly, and individual models often differ only in capacity, output, or material.
- Industry
- Mobile accessories and charging
- Size
- Epico CZ/SK
- Testing country
- Czech Republic and Slovakia
Campaign overview: sixteen products, sixteen campaigns, five slots each
Testuj.to by FRENX implemented sixteen testing campaigns for Epico on the Czech and Slovak markets from October 2024 to June 2025. Tested products included power banks (ranging from slim 3,000mAh to 30,000mAh models), Qi2 wireless chargers and stands, GaN wall chargers, a car charger, and a universal travel adapter.
Each campaign offered five slots. A total of 1,988 people filled out the questionnaire, and all 80 selected testers submitted a review.
The challenge: sixteen similar products easily confused by customers
A 5,000mAh and a 10,000mAh power bank look identical in photos. Customers can only tell them apart by specifications and reviews — and a new unrated item stands no chance in such comparison. Meanwhile, Epico launches novelties continuously, so the problem recurs with every wave.
Furthermore, demand varied thirteen-fold across products: 274 people applied for the 65W wall charger, compared to 21 for the universal travel adapter. Clarity played a key role — the more specific the product's use case, the fewer applicants turned up.
The solution: a dedicated campaign for each model, not one for an entire product line
Each of the sixteen products received its own separate campaign with a tailored questionnaire and dedicated slots. Reviews thus land on the specific product card rather than a broad product family — so a customer comparing two similar power banks finds ratings for both.
For power banks, we selected testers based on their phone model and charging habits; for travel adapters, based on destination and travel frequency. Every approved review was published on Testuj.to, Heureka, and the client's destination, with fifteen also published on idealo — totaling 255 published reviews.
Results in numbers: 80 out of 80 selected testers submitted a review
16 products tested, each in its own 5-slot campaign. 1,988 completed questionnaires (25 applicants per slot), 80 selected testers, and 80 reviews from 80 unique testers.
100% completion rate — every selected tester submitted a review across all sixteen campaigns. Average rating of 4.5 out of 5, 96% of testers recommended the product, and 211 photos were generated. A total of 255 published reviews: Testuj.to, Heureka, and the client's destination for each, plus idealo for fifteen.
What testers praised: design and charging speed, closely followed by portability
Design and appearance were mentioned most frequently as pros (38 out of 80 reviews), followed by fast charging (35) and compactness/portability/light weight (33). Next came build quality and materials — aluminum body, matte plastics (23), magnet strength and MagSafe compatibility (14), capacity (13), ability to charge multiple devices simultaneously (12), travel convenience (10), and charge status display (6).
Feature ratings on a 5-point scale: ease of use 4.81 · design 4.79 · quality 4.78 · material 4.75 · performance 4.57. Highest-rated products: UltraDrive Qi2 car charger with 5.0 out of 5 and EM71 UltraPack 10000mAh Alu power bank with 4.9.
What bothered testers: overheating and capacity insufficient for a single full phone charge
The most common group of complaints concerned packaged accessories — cables, ports, sockets, pouch, and manual: 13 out of 80 reviews (16%). Testers missed a longer or more flexible cable, a second USB-C port, clearer labels, or more detailed instructions.
Right behind, however, was a criticism the client shouldn't overlook: overheating was mentioned in 11 reviews (14%), ranging from "warms up slightly" to "extreme overheating". Ten reviews (13%) criticized capacity or battery life — specifically that a slim power bank couldn't fully charge a phone even once. Eight reviews noted slow charging, eight mentioned weak or overly bright LED indicators, seven cited magnetic strength and stand stability, and six noted price. Five reviews (6%) pointed out that the delivered color didn't match the e-shop photo — an insight regarding product listings rather than the product itself.
Nine reviews (11%) ended with a rating of 7 out of 10 or lower, with the lowest being 3. The lowest average score belonged to UltraPack EM31 3000 Slim Mag+ at 3.4 out of 5 — this model suffered from both main drawbacks at once: overheating and low capacity. This is confirmed by evaluated attributes: price/performance ratio (3.96 out of 5) and battery life (4.15) were the only two below 4.5, whereas design scored 4.79. Eight reviews (10%) listed no complaints.
Where the reviews ended up
Each of the 80 reviews was published on at least three destinations: Testuj.to (80 reviews), Heureka (80), and client destination (80). For fifteen reviews, a fourth placement was added on idealo. Totaling 255 published reviews.
Methodological note: data comes from the Testuj.to by FRENX administration database as of August 22, 2026. Review means an approved review; ratings in the database are tracked on a 1–10 scale and converted to a 5-point scale for this case study. Includes all 16 campaigns ordered by Epico for the CZ/SK market, open between October 11, 2024 and June 19, 2025.
Sample reviews
UltraBase 3v1 stojánek EF30
„Beautiful design. Adjustable. Folds down to less than 7 × 7 cm. Great stand for watching videos, for instance. Adapter included. One charger for all basic accessories."
Aluminium PD 100W Power Bank
„Charges quickly. A fully charged Epico can charge a 14" MacBook Pro from zero to 74% — in exactly one hour. Really quite lightweight for its capacity. Four ports (can fully utilize two simultaneously)."
UltraBase Qi2 2in1 Fold Mag+ EX40
„Nice design. Enables hands-free video or regular phone calls. Fast charging. Quality materials used. Ability to charge two devices simultaneously."
UltraPack EM31 3000 Slim Mag+
„Only one LED indicator, no way to check the power bank's charge level. Extreme overheating."
UltraPack Qi2 Slim 5000mAh
„Small capacity. Warms up. Advertised color doesn't match. Could charge faster."
UltraPack 5000mAh Mag+
„Won't fully charge a phone even once. Higher price."
„Working with Testuj.to brought us quick feedback from relevant customers. Thanks to authentic reviews, we gained valuable insights for both sales and marketing while boosting the credibility of our products."
Source: business.testuj.to
