Kiwi design K4 Boost Battery strap: One-minute review
This battery-equipped head strap might not be as impressive as Kiwi design’s H4 Boost Halo Battery Strap from a design perspective, but it still ticks many boxes.
It boasts a 5,300mAh battery capacity – effectively doubling the battery life of your Meta Quest 3 or Quest 3S – and the padding and adjustable plastic deliver a secure yet comfortable fit that’s an upgrade on the default fabric strap that would have arrived with your VR headset.
Best of all, it costs only $69.99 / £57 / AU$113. As such, it’s a relatively affordable option and the perfect choice for first-time or more casual Meta Quest users who aren’t ready to splash out on top-of-the line upgrades, but still want something worthwhile.
The only negative of note is that at 358g this strap weighs about 70% of what the Meta Quest 3 and Meta Quest 3S each weigh on their own. So, if you’ve been struggling with the headset’s weight already then this will add over half as much weight again and could make your VR system unmanageable.
Kiwi design K4 Boost Battery strap: Price
- Usually costs $69.99 / £57 / AU$113
- Typcially discounted during sales like Black Friday and Prime
You can pick up the Kiwi design K4 Boost Battery Strap from Kiwi design’s official store or Amazon for $69.99 / £57 / AU$113 – although it can regularly be found at a discount through both outlets.
At this price, the K4 is a more affordable battery strap for your Meta Quest 3 or Meta Quest 3S – being cheaper than Kiwi’s own H4 strap, and Meta’s official Elite Strap with battery.
- Value score: 5
Kiwi design K4 Boost Battery strap: Design
- Like an upgraded version of the official Meta Quest 3 Elite strap with battery
- Just over doubles your Meta Quest 3 headset's battery life
The K4 Boost Battery Strap shares several design similarities with the official Meta Quest 3 Elite Strap with Battery. It’s a hard plastic strap with a battery at the rear, which can be adjusted to fit the size of your head. The hard plastic with padding ensures the design delivers a secure yet comfortable fit on your head; it feels significantly more solid on the head over the fabric strap the Quest 3 headset comes with in its box.
There are some differences between this and the official plastic battery strap, however. The first is that the head strap is padded for additional comfort, and the other is the Kiwi design has a hinge half way along each side.
Not only does this hinge help you to find a better position for the strap on your head; it means you can more easily put on and take off the headset without putting stress on the arms as it just folds up.
I had previously used an official Elite Strap with my Meta Quest 2, but it snapped on one side – roughly where the K4’s hinge is positioned – following just a few months’ use. Based on the K4 Boost Battery Strap’s design then, I expect it to be more durable.
As for the battery itself, beyond serving as a counterweight to the front of the headset, helping improve the comfort of your setup, the 5,300mAh unit will more than double the length of time for which your Meta Quest setup can be used. The Quest 3S features a 4,324mAh capacity battery and Quest 3 a 4,879mAh battery, so with the K4 supplying an extra 5,300mAh, you can expect to run each device for just over double the time.
What’s more, while the K4’s battery pack is hooked up to your Quest 3 using the built-in USB-C cable, you can use your Quest’s USB-C charger to refuel both the headset and strap simultaneously. Kiwi design promises that a 45W charger can restore 60% charge to your headset and 65% to the strap in an hour – just like its H4 battery strap – by dividing 22.5W of power between the battery and headset.
The only downside to consider here is that the battery isn’t light. At 358g, the K4 strap weighs about 70% of the Meta Quest 3 or Meta Quest 3S on their own. It’s lighter than some battery straps, and from my experience makes up for the weight with added comfort. However, if you already struggle with the weight of either headset then you may prefer Kiwi’s K4 Comfort Strap (which is identical except it lacks the built-in battery).
In addition, the K4 Boost Battery Strap doesn’t offer as much in the way of adjustments as more high-end options such as the H4 Boost Halo Battery Strap – which includes an adjustable front cushion, for example. However, the latter is also more expensive, so this is to be expected.
- Design score: 4/5
Should you buy the Kiwi design K4 Boost Battery strap?
Buy it if…
You’re on a budget
If you want an affordable but capable battery strap then this is one of the best options we’ve tried.
You want to stay in VR for longer
This battery strap effectively doubles the battery life of a Meta Quest 3 or Meta Quest 3S, meaning you’ll be able to play VR and MR games for longer.
Don’t buy it if…
Your Quest 3 feels too heavy already
This battery strap weighs about 70% of a Quest 3 or Quest 3S headset alone, so you may prefer the K4 Comfort instead, which comes without the battery.
You demand something high-end
This strap lacks some of the adjustability of slightly more high-end VR headset straps.
How I tested the Kiwi design K4 Boost Battery Strap
To test the Kiwi design K4 Boost Battery Strap thoroughly, I attached it to my Meta Quest 3S and used it as my primary head strap on that headset for a few weeks. I also made sure to swap between the K4 and the base strap to compare, while also pitting against the Razer head strap and the Kiwi design H4 Boost Halo Battery strap (which was attached to my Meta Quest 3) to contrast different third-party options.
- First reviewed March 2025
