Petzl NAO+ EnerPower replacement battery review

The Petzl NAO series has been a stable of adventure sports for as long as it’s been around, amazing brightness, good battery life, sturdy but well balanced – few other headlamps have garnered the same following as this one.

But at £120 retail it is an expensive piece of equipment, but that’s ok you say it will be the only headlamp I need – indeed… but if you are doing long night trips that require the brighter settings or a multi-way trip it is likely you will need a spare battery.

The NAO and NAO+ do not take standard sized batteries (e.g. AA or AAA) to allow cheap disposable replacements to be taken, oh no, on the contrary the battery compatibility of these is insanely complex as you can see from the diagram below showing the compatibility between the latest and older models:

So if you have an older model, which many people do, the batteries will not work with the new version, the NAO+ despite sharing the same connector.

So OK I need a spare battery…

That’s ok, they sell spares that come in the full shell package like this:

£60 retail… £60!

That is a lot of money, especially considering the amount you shell out for the headlamp in the first place.

But there is another way, but is it a good idea? There is very very little on the internet about what I am going to share with you but I decided to take the plunge and try it out.

The Enerpower 3,450mah replacement battery

That’s not the same thing you say! It is the same core battery but not with the outer shell. Not having a case means to charge it you need to open one up (simple) and replace the one in there during charging.

Including shipping from Germany I got this for around £26 on eBay here – please note I have NO affiliation with this manufacturer, brand or reseller, I do not warrant any of these products or recommend them beyond my own experience!

If you look carefully the battery in this headlamp is actually a simple 18650 battery with some extra circuits on the end.

If you are interested about what an 18650 battery is…

18 = 18mm diameter, 650 = 65mm in length.

The capacity of the original battery in my headlamp bought in late 2019 is 2,600mah but I notice it is now listed as 3,100mah.

Is it any good?!

First things first – Petzl don’t want you to use this battery, in fact they made it almost impossible for you to use an off the shelf battery. You can’t buy an 18650 battery (which cost very little) and use it, there is a special circuit on the end with a connector. I also suspect using a 3rd party battery will invalidate the warranty.

But at a fraction of the cost it does function nicely – with some caveats, read on for details.

I will compare it to my version with the 2,600maH battery, which makes this replacement one 32% bigger in capacity.

That should equate to

  • On the ultimate highest power going from 1:20Hrs to 1:46Hrs.
  • Ultimate Reactive mode going from 22:00Hrs to 29:15Hrs.

Those could be some big increases but to make sure I did a back to back comparison, at room temp on the highest power setting and here are the results:

  • Original battery: 1:29Hrs (19mins longer than specified which is good)
  • EnerPower battery: 1:29Hrs


There is always a but…

Yes here comes the issue – The outer shell of the battery pack includes not just the charging circuit but also some communication software to the head unit which tell it what the battery is, charge level etc.

That means the head unit doesn’t determine the actual charge to work out if it should go in to power saving mode but an estimated value based on what it thinks the battery should be at – which if you ask me is silly.

So whilst we might have a larger capacity battery the ability to use it isn’t there because of the control circuits. Now an interesting experiment I did is by turning it off and on a few times was I got the light to come back on even though the app was reading 0% and got another 8mins at full power which I couldn’t from the original. So with some faffing you can get a boost from this battery.

Here is the bigger issue…

If that wasn’t annoying enough there is a bigger problem with the concept of carrying this as a spare battery which you just swap out – when you swap it over it still thinks the battery (unit) is flat and won’t power on properly.

You can get around this with two tricks but they aren’t without issues:

  1. Put the new battery in to the shell and charge it for about 10mins to get it to register as being recharged and it will allow you to turn it on again. Though for some reason it always says 80% even when it is nearly fully charged.
  2. Put the new battery in while connected to the headlamp and with the rotary switch turned while you plug it in. It is mad I know but it does work… however, for some reason it turns on but doesn’t allow you to go through the modes just the first one. Why? I have literally no idea!

So should you get one? If the old battery is dead this is a great replacement at half the price of the original so yes recommended, if it is as a spare you need to use reliably in the field then no I would suck up the pain and get the full stock unit.

Enjoy, now go f’ing run.

12 thoughts on “Petzl NAO+ EnerPower replacement battery review

  1. Super frustrating the whole Petzl battery thing. I mean for an eco conscious company why don’t they just make the battery and proprietary connector that can relay the charge back available to consumers. I mean it’s easy to remove the battery and replace. I guess it’s down to making money. I’m stuck with 2 cases now and no battery as a dead battery in year 2 (not overly used either) doesn’t fall under their 3 year warranty for the head torch as that excludes the battery itself.

  2. I’ve been using these replacement batteries extensively for five years now and never had any issues whatsoever. I bought 3 of them, replacing the original 2300mAh NAO (non-plus) batteries. I’ve run them for five nights straight a few times in difficult terrain navigation-wise. I often got two 9-hour nights out of a single battery. Best 48 euros I ever spent 🙂

    1. Awesome – thanks for info, great to hear from people using them over a longer period of time. I have now been using mine for about 12months and still doing well though I rarely get quite as long out of mine! Do you have the batteries in different cases or just swap the cells out?

  3. This is why I will stay away from Petzl headlamps forever now.
    First the Petzl software for original NAO headlamps was garbage and soon became unusable for Mac users (hopefully I set my lights up quick and for good now) then this battery thing.

    I had Petzl in high regards, not anymore. That is just built-in obsolescence, very far from Petzl values on paper.

    1. Companies like Black Diamond do seem to be able to knock out lights of similar performance at a better price but the main I think that Petzl are lacking on is their water resistance on the big lights like this one.

      I do like the Nao+ and the light pattern is great, the app is pretty much flawless (which I was surprised at) but just want to know it will survive a really big storm!

  4. Hi,

    Great article – I just wanted to point out that it is possible to use standard AAA batteries in the case, at least in the white and the black cases. These cases are labeled as such. Looking at your red case, the contacts seem to be missing. So it is possible that only the red case lacks the support for replaceable batteries.

  5. I have an older model NAO RL (not NAO+) and have tried to exchange the rechargeable battery for the one you have tested. So far all your tricks don’t work for me. But when almost ready to recycle the lamp, I just realized, it accepts 2x normal AAA batteries. And it works, but the only mode available is maximum brightness. Still something 😉 Probably this possibility was eliminated in NAO+?
    I don’t know yet, how long these 2 batteries will last, but even if not long, it’s still good to have a working lamp, just in case, instead of send it to recycling 🙂

    1. Really interesting that you got it to take 2 AA batteries! The Li-Ion batteries these take are 3.7-4.2V and two AA batteries are about 2.4-3V so surprised it works but good to try it, I know a lot of people that would love a AA battery solution for these to meet the requirements for races that need spare batteries.

      1. Yeah, but it only works for old NAO old model, NL+ has no contacts or place in the shell to accommodate AAA batteries. And I don’t know yet, how long it will work. Still for someone who has working rechargeable battery it’s maybe good idea to have some AAA in the pocket. The only problem would be, how to replace the rechargeable with AAA in the dark 😉
        Still better than nothing.
        I have asked the Petzl support what is the workaround but I guess they prefer us to buy new model.

  6. Re voltage. Yeah, rechargeable (replacement) has nominally 3,6V, but it’s not like you use 1,2V rechargeables instead of 1,5 normal batteries. You just use normal batteries 1,5V each. And you don’t place them in the same slots, but in another, dedicated slot for AAA batteries. So it must be somehow adapted to different voltage. And what decides about lighting time, will be the capacity (default is ca. 1000 mAh for a single battery, so 2000 mAh for 2 batteries. Not that bad. The worse is, you cannot use levels, but only maximum light intensity, so it will not last very long. If it’s not enough for the planned night trip, youl will need to have some spare batteries in the pocket and replace them in the dark (well, maybe the moon helps ;)).

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