NP-W126S Batteries Test: Capacity, Temperature and Quality compared

The original Fujifilm’s batteries for X system camera are expensive. That’s the reason why there are so many alternatives available, but it also makes the choice of the right one touch. They not only vary in price and capacity, but some 3rd party batteries can even swell in camera and potentially damage it. This article will hopefully help with the right choice due to extensive testing of capacities and heat characteristics of several available brands.

NP-W126S

Each of the Fujifilm X-System cameras requires a NP-W126 or the newer NP-W126S battery for their operation. It’s definitely a good thing that people having multiple bodies don’t need multiple battery types and multiple chargers. This allows me to carry a backup X-M1 or X-T1 to my main X-T2 body while having just a single type of batteries. A little less exciting fact is that the original Fujifilm batteries are quite expensive, particularly considering their capacity and the price of similar Li-Ion batteries. Since you need quite few of them for real usage, it can cost quite a lot. Note that their capacity is considerably lower than a typical DSLR camera battery, while Fujifilm X-System cameras require much more power than a typical DSLR. NP-W126 is rated for 350 frames in X-T2 according to CIPA standard. Real life figure can certainly differ in both directions significantly. In case of long exposures in freezing temperatures you can expect much lower, but in case of continuous shooting it can easily be double of the specification. Note that in case of DSLR, the specs are usually in the range of 1000-1300 frames per battery.

NP-W126 vs. NP-W126S

In 2016 Fujifilm introduced an updated version of the NP-W126 battery, with ‘S’ added to the title. This created quite a bit of confusion regarding its uses, advantages, etc. So, to clarify, both batteries share the same dimensions, contacts and power characteristics — both can deliver roughly 1200 mAh. They are interchangeable for any use in Fujifilm cameras as long as you don’t use power demanding features, which particularly means 4K video recording or an intensive continuous shooting. The NP-W126S is supposed to be thermally more efficient and thus able to better handle substantial loads. So, if this is your use-case, the decision is quite easy — you should purchase the updated NP-W126S. To confirm this claim though, I made temperature measurements with results presented later in this article.

Original vs. non-original Fujifilm NP-W126S batteries

The alternative for the original batteries are third-party ones that are available under many brands from most sellers, usually for about $15, sometimes even lower than $10. However, are they at least as good as the original? Their description often claim rather unbelievable capacities (e.g. 1900mAh, the original has 1200mAh!), while forum posts usually say that their capacity is lower than original. I decided to purchase few and measure by myself.

Capacity Test

I started by taking series of long exposures (30s) and measuring the decrease of voltage in the battery. It would certainly work for battery comparison, but soon I decided that I’m not ready to use my almost new X-T2 just to test a bunch of batteries. So, I needed something to discharge the batteries, preferably with direct measurement of mAh. The easiest and cheapest option I found was iMAX B6 (about $30), a balance charger that’s capable of more that just charging. When it arrived, the process of measuring the batteries was finally fast and easy. I set it up to discharge it at 0.8 Amperes current and measured how much each battery can deliver.

Results


NP-W126S

NP-W126

ExPro White

Patona

MaximalPower

DSTE

Noname
Usual price $60-70 Discontinued $18-$28 ~$13 ~$13 ~$10 ~$8
Made in China China China China China China ?
Claimed capacity min. 1200 mAh, typical 1260 mAh min. 1200 mAh, typical 1260 mAh 1260 mAh 1100 mAh 1200 mAh 1900 mAh 1600 mAh
Measured capacity 1211 mAh 1233 mAh 1151 mAh 1091 mAh 1097 mAh 956 mAh 951 mAh
Temperature 30.3 °C 32.3 °C 30.6 °C 31.6 °C 31.5 °C 35.6 °C 39.4 °C

Unfortunately, the results show that only the original batteries are able to deliver maximum performance. This conclusion is in contrary to how voltage dropped during my very first testing of full batteries using long exposures — there was no measurable difference, at least not while I tested almost full Fujifilm and DSTE batteries. In order to get a clearer picture of what’s going on, I made a chart of how the voltage decreases with more power taken from the batteries:

OK, now it’s much clearer! While discharging, until about 7.8V all the batteries show about the same performance. Then suddenly (and surprisingly) the non-original batteries start to lose voltage slower than the original ones, indicating that they might possibly deliver more power? No, at about 7.3V they suddenly start losing voltage at enormous rate and very quickly get fully discharged, while the original battery continues to deliver power with more or less constant voltage loss.

There’s also an interesting pattern, apparently some batteries have the same voltage curve, indicating that they were manufactured the same way, possibly even in the same Chinese factory and only differ in branding.

 In-camera battery indicator

The battery indicators in all older Fuji cameras unfortunately only have 4 states (full or 3 bars, 2 bars, 1 bar and empty). This really isn’t granular enough and doesn’t give photographer proper information about how much is remaining. The chart above can give us at least a little better picture regarding the remaining capacity based on the in-camera indicator. Based on the chart we can deduct how much of the battery remains when there is a change in the battery indicator:

Voltage when the change occurs Fujifilm battery (remaining power) Other batteries (remaining power)
3 bars=>2 bars 7.20 V 40% 10%
2 bars=>1 bar 6.70 V 10% 1%

Ooh, that hurts! While the indicator isn’t too useful for the original batteries, it’s next to useless for other batteries, where the in-camera indicator shows full battery for roughly 90% of the battery capacity! So, when it drops to 2 bars, you possibly won’t even finish a single longer exposure in freezing temperatures. Be warned!

Fortunately it’s much better in X-T2 and X-Pro2, where a more granular battery indicator, or even percentage, is available. That said, given the different voltage curve of non-Fuji batteries, even such detailed indicators can be misleading when batteries are nearly depleted.

Temperature test

X-T2 after 4K video recording

In order to confirm the claim that the new NP-W126S has better heat dissipating capabilities, I measured temperature of individual batteries in two tests: after 10 minutes of 4K video recording in X-T2 and after 20 minutes of 1A load in my (dis)charger. The results of both tests were similar, but the one made in camera seemed to be a little biased by the internal camera temperature and so the results in the table above presents results from the second test.

The new Fujifilm’s battery really seems to handle extended high loads better, even though other good batteries aren’t much worse. Only the batteries with the lowest capacities don’t perform that well in this test — while DSTE was only about 4-5 degrees warmer, the noname brand started swelling, probably due to higher power load of the camera making 4K recording. This was the end of the test for this battery, and actually the end of this battery for me altogether.  😉

Fujifilm NP-W126S (30.3°C)

Unbranded battery (39.4°C)

I also used my thermal camera, Flir One for Android (iOS version exists too), to capture batteries after a heavy load. While the original battery shows mostly evenly distributed heat on its surface, the noname battery has much higher temperature in a smaller rectangle in the middle. This might be the reason for swelling of some batteries.

Self-discharging

I haven’t done any rigorous testing in this area, so far I’ve just tried to put all the brands to a fridge for few days, but haven’t measured any significant loss of charge. Even when not used for a long period, none of my batteries suffered any significant discharge.

Other brands

There are many other brands available worldwide. I suppose that only very few are unique though, as the test above shown, they are probably most often re-branded versions of the very same product.

There are several brands worth mentioning. Particularly in the US there are WasabiWatson and Green Extreme batteries popular. Wasabi batteries have been reported by several users to get hot and swell in camera, making it hard to get them out. Based on some online posts, my guess is that they are in the same league as the DSTE brand, i.e. roughly 950 mAh. I wouldn’t recommend them based on this, but without proper testing, take it with a grain of salt. Green Extreme are presumably good, but also rather pricey at about $30. I’ll try to get hand on some of these brands in the future in order to test their performance.

Conclusion

I’d consider the batteries to be one of the weaker parts of the whole Fujifilm mirrorless system. OK, they are small and light, but they don’t deliver nearly as many frames as typical DSLR batteries. When combined with the limited in-camera battery indicator, you must be careful to avoid problems, particularly when non-Fuji batteries are used.

If you want the ultimate performance or you do a lot of 4K video recording or continuous shooting, NP-W126S is clearly the winner. That said, some of the third party batteries are very close to the Fujifilm’s original in performance, while they cost only a fraction of the price. Particularly in Europe there are very good ExPro White and almost as good Patona available. In the US the best tested is MaximalPower. All of them offer >90% capacity of the original batteries and also they don’t seem to produce significantly more heat even after some heavy use.

I plan to update this page in the future, when I test other batteries. There will also be other articles published about Fuji X system, charging, including solar and more. If you want to be notified about updates, just follow this website on Facebook or RSS.

Purchase links for recommended batteries:

By using these links you don’t pay more, but it supports this website. Thanks!

 

Update 05/18/2017: Added ExPro White battery and temperature measurements for all batteries.