Which battery does the Sony A7S take?
The Sony Alpha A7S is a professional mirrorless interchangeable lens camera that features a 12MP sensor. It is powered by the Sony NP-FW50, which is a rechargeable Lithium-Ion battery pack. Lithium-Ion batteries offer a high energy density and low self-discharge, and are nowadays found in many portable electronic devices.
The NP-FW50 operates at a voltage of 7.4V and has a capacity of 1020mAh. It can be charged from a standard electrical outlet via the Sony BC-TRW charger (that can be purchased separately, for example, at amazon). The battery pack measures 31mm in width, 18mm in height, and 45mm in depth. It weighs 43g. The NP-FW50 has been on the market since May 2010 and sells at good camera retailers, such as amazon, for about $70. Generic alternatives (see below) that are compatible with the Sony Alpha A7S can be obtained at substantially lower cost.
It is noteworthy, that the Sony A7S supports internal charging of its battery pack via the USB port. This feature can be particularly useful when travelling, as one can re-charge the camera battery simply by plugging a USB cable into one's laptop, rather than carrying a separate battery charger along.
How many shots can I take with a fully charged NP-FW50?
The number of shots that one can get out of a battery pack depends heavily on the style and imaging practice of the photographer. For example, the extended use of the LCD screen for framing or reviewing will result in reduced battery performance.
The Camera & Imaging Products Association (CIPA) has established guidelines (click here to download the pdf-document) that manufacturers are supposed to respect when reporting the battery life of their cameras. According to this CIPA-rating, the Sony A7S can take 380 images on a single charge. Given the relatively demanding energy usage of the CIPA procedures, this rated number should be achievable or be surpassed in most practical situations. However, if the environment is cold, the LCD screen is used heavily, or the camera is turned on and off frequently, battery mileage might drop below the rating. Also, as the battery pack ages, its performance will tend to deteriorate.
What about generic battery packs?
Sony sells the original NP-FW50 pack at quite a steep price. This premium pricing strategy has left room in the market for third party suppliers to offer fully compatible battery packs at much lower prices. Savings from buying generic replacement batteries can amount up to 70 percent of the price of the genuine battery pack.
Sony NP-FW50 Specifications
|Battery type:||Rechargeable Lithium-Ion power pack|
|Compatibility:||Sony A7S & other selected Sony cameras|
|Capacity:||1020mAh or 380 shots (CIPA) with the Sony A7S|
|Dimensions (W x H x D):||31 x 18 x 45mm|
Indeed, one can easily find a variety of competitively-priced NP-FW50 replacements from different vendors at major online platforms (see, for example, here on eBay). All these generic alternatives should work fine with your Sony A7S. So why would anybody then buy the more expensive original battery? Well, below are some arguments in favor of the genuine NP-FW50, which can perhaps be summarized as "peace of mind".
- Assurance that the warranty of the camera will not be rendered void if a battery-related failure occurs;
- Assurance that the battery pack will indeed have the stated capacity;
- Assurance that the battery will have low self-discharge rates and, thus, will hold its charge even when not in use;
- Assurance that the power unit will not trigger any warning messages on the camera and can be effectively charged with the standard charger;
- Assurance that the manufacturing process has respected the safety guidelines for Lithium-Ion batteries;
If you can live without these assurances, then you are in for some nice savings from buying generic replacements for the NP-FW50. Unfortunately, the market for generic battery packs is rather fluid, with new trade names popping up regularly while others disappear. Hence it is difficult to keep track of all the suppliers and the quality of their products. That said, in North America, battery packs from Wasabi have gained a good reputation, while in Europe, replacement power packs from Patona have received many favorable reviews. In any case, the existing comparisons tend to find that the cheapest of the generic replacement packs score worse in terms of achieving their rated capacity, holding their charge over time, or allowing for a large number of charge-discharge cycles than somewhat pricier battery packs (or the genuine Sony offer). Thus, the old adage, "If the price sounds too low to be true, it probably is" has some merit with respect to camera batteries also. You can check the current offers and prices for the original NP-FW50 and its clones by using the buttons below.
Which other cameras use the Sony NP-FW50?
The Sony A7S is not alone in using the NP-FW50. Several other cameras from Sony are powered by the same type of lithium-ion pack. The adjacent table lists some of them along with a selection of their headline specifications.
|Sony A7||NP-FW50||340||Full Frame||24.0||474||Oct 2013||1,699||-||Sony A7|
|Sony A7 II||NP-FW50||350||Full Frame||24.0||599||Nov 2014||1,999||-||Sony A7 II|
|Sony A7R||NP-FW50||340||Full Frame||36.2||465||Oct 2013||2,299||-||Sony A7R|
|Sony A7R II||NP-FW50||290||Full Frame||42.2||625||Jun 2015||3,199||-||Sony A7R II|
|Sony A7S||NP-FW50||380||Full Frame||12.0||489||Apr 2014||2,499||-||Sony A7S|
|Sony A7S II||NP-FW50||370||Full Frame||12.0||627||Sep 2015||2,999||Sony A7S II|
|Sony A3000||NP-FW50||470||APS-C||19.8||411||Aug 2013||329||-||Sony A3000|
|Sony A5000||NP-FW50||420||APS-C||19.8||269||Jan 2014||449||-||Sony A5000|
|Sony A5100||NP-FW50||400||APS-C||24.0||283||Aug 2014||549||Sony A5100|
|Sony A6000||NP-FW50||360||APS-C||24.0||344||Feb 2014||599||-||Sony A6000|
|Sony A6100||NP-FW50||420||APS-C||24.0||396||Aug 2019||749||Sony A6100|
|Sony A6300||NP-FW50||400||APS-C||24.0||404||Feb 2016||999||-||Sony A6300|
|Sony A6400||NP-FW50||410||APS-C||24.0||403||Jan 2019||899||Sony A6400|
|Sony A6500||NP-FW50||350||APS-C||24.0||453||Oct 2016||1,399||Sony A6500|
|Sony NEX-3||NP-FW50||330||APS-C||14.0||297||May 2010||599||-||Sony NEX-3|
|Sony NEX-3N||NP-FW50||480||APS-C||16.0||269||Feb 2013||499||-||Sony NEX-3N|
|Sony NEX-5||NP-FW50||330||APS-C||14.0||287||May 2010||699||-||Sony NEX-5|
|Sony NEX-5N||NP-FW50||460||APS-C||16.0||269||Aug 2011||699||-||Sony NEX-5N|
|Sony NEX-5R||NP-FW50||330||APS-C||16.0||276||Aug 2012||749||-||Sony NEX-5R|
|Sony NEX-5T||NP-FW50||330||APS-C||16.0||2776||Aug 2013||699||-||Sony NEX-5T|
|Sony NEX-6||NP-FW50||360||APS-C||16.0||345||Sep 2012||999||-||Sony NEX-6|
|Sony NEX-7||NP-FW50||430||APS-C||24.0||400||Aug 2011||1,349||-||Sony NEX-7|
|Sony NEX-C3||NP-FW50||400||APS-C||16.0||225||Jun 2011||599||-||Sony NEX-C3|
|Sony NEX-F3||NP-FW50||470||APS-C||16.0||314||May 2012||599||-||Sony NEX-F3|
|Sony RX10||NP-FW50||420||1-inch||20.0||813||Oct 2013||1,299||-||Sony RX10|
|Sony RX10 II||NP-FW50||400||1-inch||20.0||813||Jun 2015||1,299||-||Sony RX10 II|
|Sony RX10 III||NP-FW50||420||1-inch||20.0||1051||Mar 2016||1,499||-||Sony RX10 III|
|Sony RX10 IV||NP-FW50||400||1-inch||20.0||1095||Sep 2017||1,699||Sony RX10 IV|
Sony NP-FW50 FAQ
The NP-FW50 is the standard power source for the Sony A7S. As such it is an indispensable camera accessory. Below are some additional questions and answers concerning some particular aspects of the battery pack and Lithium-Ion power units more generally.
Is there a car charger available for the NP-FW50?
Sony does not offer a travel charger, but third party suppliers do (see here on eBay).
Is the NP-FW50 available in colors other than black?
No, Sony supplies this battery pack only in black. However, some generic alternatives from third party providers might be available in other colors.
Can I use the NP-FW50 in any of my other electronic devices?
No, the battery is specifically designed for use in the Sony A7S and other selected cameras from Sony.
How should the NP-FW50 be stored?
Lithium-ion batteries can hold a charge for a long time. However, these battery packs have a safety mechanism built-in that disables any re-charge if the voltage drops below a certain minimum level. To avoid this safety-trigger to be activated, the battery pack should be charged at least once every few months.
How should I discard my old battery pack?
The contents of Lithium-Ion batteries is under pressure and the packs can explode if exposed to extreme heat. Lithium-Ion battery units should therefore never be incinerated and should not be thrown into the household trash, but put into the recycling stream. Most places that sell camera batteries will also accept them back for recycling.