Kalenji Onnight 410

Mar 23, 2021 - Written by Leander
Kalenji Onnight 410
Octos are nocturnal, so obviously they need a light. But do they have a head but no body, or a body and no head..?

Table of Contents

As of September 2019, Decathlon issued a recall on this light, as apparently it can overheat during charging. So far only one example of this is known, but they don’t want to take the risk. If you have one of these lights they will give a full refund.

BTL: It seems that there is no limit on the input voltage as my QC3 charger manages to charge the light in 20 minutes, so if using this light, it might be best to limit the charging to 1A.

Now for the review, which I’ve written a few weeks prior to the recall. It talks about melting buttons and puffy batteries, but not due to overheating…


I remember my first head-torch. I was so used to holding a torch that this was like a revelation. No more juggling the torch while running or making camp food. Hands-free light everywhere!

After the buttons of my first head-torch turned into goo (:yuck:) I decided to try Decathlon’s head-torch, the Onnight 410. It’s a product very true to Decathlon’s idea of ‘simple, effective, affordable’. For about a quarter of the price of my first head-torch I got a 200+ lumen, three mode light, powered by a usb rechargeable battery. It’s lightweight and is, as always at Decathlon, backed by a two year warranty. My girlfriend bought one as well when we started our first tour together.

Everything was well, until one of the lights started to smell like apple. Google told me this was a sign of a faulty lithium battery. The store’s mechanic opened it up and in there was a perfectly fine battery. Strange. Almost a year later the battery’s housing was slowly being cracked open by the swelling battery. We returned it and got a replacement, the Onnight 420, a newer version.

puffed battery in headlamp
It's like running around with a bomb strapped to your head. Apart from that it's a nice light!

The other original got a button that was getting soft and sticky and didn’t want to turn on reliably anymore. Decathlon’s warranty fixed this too with an exchange to the Onnight 420.

The new ones so far work flawlessly. They’re a little brighter according to the specs and have a black headband instead of orange.


It’s a very minimalistic designed head-torch. A 220 lumen light featuring three modes: low-high-strobe, a 2200mah LiPo battery that is usb rechargeable and a headband with extra strap over the top of the head. The lighthead can turn in any direction, which greatly improves the usability of this head-torch.


Does what it needs to do and nothing more, and thus keeping it lightweight. Battery lasts for two full nights on low. Well picket brightness settings for low and high. Lighthead can turn in any direction. Top-of-head strap improves stability when using it on a night run.


Our first two both failed. Not sure how well the replacements will hold. Time will tell… No red light mode. Red light preserves your night-vision. Having to cycle trough all modes every time.


IF the Onnight 420 holds better than the 410, then this is a great head-torch. I like Decathlon’s idea of creating products that just do what they need to do, and leaving all the bells and whistles aside. I have some reservations about their current quality though.