Nerunsa Wireless Earbuds Review: 8 Hours per Charge, a 35ms Latency Figure and an Invalid IP7 Code

Description

The Nerunsa is a sea blue true wireless set, ASIN B0F1TB2KPJ, listed since March 2025, carrying a 4.8 star average across 672 ratings and ranked 7,087th in Amazon’s Earbud and In-Ear Headphones category. Both the Model Name and the Item model number fields read simply “1”, which means this product has no model designation to search for beyond the brand and the ASIN. Keep the ASIN if you ever need a replacement or a spare, because there is nothing else to identify it by.

Who this suits

The pitch is general purpose: journeys, meetings, calls and music, with three tip sizes, touch controls on both buds and a wireless charging case. The buyer wants a sealed bud with a long day of runtime and does not need cancellation or an app.

On cancellation, the title says “4 ENC Noise Cancelling Mic” and that is exactly what it means: four microphones running Environmental Noise Cancellation on the call side. ENC improves what the person on the other end of a call hears. It does nothing about the noise reaching your own ears. There is no active noise cancellation on this product and none is claimed in the specification. If cancelling what you hear is the requirement, sets with a published ANC design in the true wireless earbuds section are the right shortlist.

Connection: a latency figure worth having

Bluetooth 5.4 is stated, along with support for the HID, HFP, A2DP and AVRCP profiles. Those are profiles rather than codecs, covering control input, calls, stereo streaming and playback commands, and every Bluetooth audio device supports the audio ones. HID appearing where HSP normally would is unusual and is typically an input device profile, so read that list as approximate.

The useful number is the latency claim: 35 milliseconds. That is a genuinely low figure, well inside the range where video lip sync and casual gaming feel synchronized, and it is far better than the 100 millisecond figures some competitors publish. No measurement method is given and latency also depends on the source phone, so treat it as a manufacturer figure rather than a tested result, but it is a real disclosure and most rivals give nothing at all. No Bluetooth range figure is published.

Multipoint pairing to two devices at once is not mentioned. Neither is a companion app, transparency mode, wear detection or firmware updating. Assume none of them exist.

The sampling rate claim

The first bullet says the 13 millimeter dynamic drivers have “a higher audio sampling rate and bit depth”. Sampling rate and bit depth are properties of the audio file and the codec carrying it, not of a speaker driver, so that sentence does not describe anything a driver can do. No codec is named anywhere on this page, which means there is no supportable high resolution claim here despite the title using the phrase “HiFi Stereo”. Assume SBC only, the baseline every Bluetooth device supports. There is no impedance, sensitivity or frequency response figure either.

Battery: the split is published cleanly

The third bullet gives both halves: 8 hours from a single charge and 45 hours in total with the LED charging case, with a full charge of both taking 1.5 hours over USB-C. Eight hours per charge is the number that governs your day; 45 hours is how long the whole system runs between wall charges, implying roughly four and a half recharges held in the case.

This is a clean disclosure by the standards of this catalog, where most listings quote only the combined figure. What it does not say is the volume the measurement assumes, and every quoted playtime is a best case at moderate volume with no cancellation running, which here is not a variable since there is no ANC. For comparisons in the same runtime band, the XIAOWTEK A40 Pro and the GNMN V7 publish their figures the same way.

One specification field is import noise: Batteries reads “1 A batteries required (included)”. No A cell goes into an earbud; these use built in rechargeable cells.

Fit, controls and the water code that is not real

The fitting story is good. Three sizes of soft ear tips ship in the box, itemized as small, medium and large, and each bud weighs 3.9 grams. Tip sizes are the specification that most decides how a sealed set sounds to you, because a bud that does not seal loses its bass and sounds thin. The fifth bullet describes the contact surface as shaped to the inner contour of the ear, which is standard copy rather than a measurable claim.

Controls are touch on both buds with a full gesture set covering volume, playback, track skip, calls and the voice assistant. Volume control on the bud itself is worth noting, because plenty of rivals drop it to save gestures.

The water claim is broken. The title says “IP7 Waterproof” and the fifth bullet repeats “IP7 waterproof, which means they can take dust, rain” and so on. IP7 is not a valid IP code. Real codes carry two positions, one for solid ingress and one for liquid, which is why genuine ratings read IPX4 for splash resistance or IPX7 for immersion. Note also that the bullet claims dust protection, which an IPX code explicitly does not cover, since the X means the solids digit was never tested. The correct reading is that no water or dust rating is published for this product. Treat it as sweat resistant at best, and remember that even a real IPX7 excludes seawater, chlorinated pool water and pressurized water while degrading with age and heat.

Because these seal the ear canal and have no transparency mode, they are the wrong product for cycling or road running. Sealing your ears removes your awareness of traffic. Use them indoors, and choose an open design for road use.

What is missing, and the alternatives

Not published: codec, impedance, frequency response, Bluetooth range, driver material and charging case capacity. Package weight is 3.2 ounces, which is the shipped box rather than the buds. Included Components reads only “Wireless Charging Case”, which understates the three tip sizes the bullets itemize.

For alternatives with comparable published detail, the JLab Go Air Tones comes from an established brand at similar money, and the BESNOOW I53 covers the same budget brief. A wider shortlist sits in the in ear and earbud style headphones section.

Who should buy this, and who should not

Buy it if 8 hours per charge and 45 hours total suits your week, you want three tip sizes and full touch volume control, and a 35 millisecond latency figure matters for video. A 4.8 star average across 672 ratings is a substantial signal, and publishing both a latency figure and a clean battery split puts this listing ahead of most of its rivals.

Do not buy it expecting active noise cancellation, since the ENC label is a call feature. Do not read “HiFi Stereo” as a resolution claim, because no codec is named. Do not treat “IP7” as a rating, and disregard the dust protection claim attached to it. And do not use these on a road bike.

Additional information