3rd party batteries for A7 series

beautiophile wrote: Nowadays, the quality gap of battery cells among manufacturers is relatively small. The importance is the battery circuit board which controls the discharge and communication with the camera.

The danger is that (as happened a lot with nicads and Nimh cells) the manufacturers don't throw away cell batches that fail to meet their test criteria, but sell them off for less critical applications ... and these re-enter the camera battery market by unscrupulous 3rd party firms.

There is. Many of the Chinese camera batteries appear to be recyled maanufacturing rejects with false labels. They *may* work for a while but are quite likely to give problems.
If you don't want to pay Sony prices, look for alternative parts from reputable suppliers, or buy from a shop and take their advice. I've found Duracell and Ansmann reliable.

Dave18 wrote: Found this article testing 3rd party alternatives to NP-FW50 batteries https://www.outsidetheshot.com/sony-np-fw50-batteries/ Interesting

Interesting link. Unfortunately 'capacity' is only half the problem - the other half is the internal resistance. I did some detailed battery testing a while ago on Sony and non-Sony batteries (both NP-FW50 and the larger ones from A-mount cameras), and discovered that the NP-FW50s have borderline internal resistance for the loads taken.

The result is that the voltage falls under load so much that the camera will cut out before the nominal capacity is reached on ALL batteries (even Sony). The difference is that expensive top-brand batteries have a lower internal resistance and will maintain voltage under load quite a long way into their capacity, whereas the cheap ones (probably recycled factory-test rejects) drop below the minimum permitted voltage very quickly.

Testing at the 1-hour rate will pick this up, if you set the endpoint voltage correctly* for the camera concerned and don't rely on the charger/cycler's internal setting.

The larger capacity on the -500H batteries makes them less sensitive to this problem (and the A-mount cameras often use less current too) which is why cheap Ebay batteries often work okay on the later A-mount cameras.

*I should point out also that 3V is NOT a suitable end-point. This is the damage voltage! A fully-charged (modern) Li-Ion or Li-Polymer prismatic cell (the flat ones) is 4.2V. Capacity is ALL used up by the time the battery EMF (its internal driving voltage) reaches 3.7V, though the terminal voltage may be less than this under load. A good tester releases the discharge current briefly to measure the terminal voltage, then resumes discharge.
I think the Sony camera I tested cut off around 7.2V. I did show a graph here the last time this came up.


Edited by Miranda F - 03 January 2021 at 20:50

Since I joined Sony gang I had to use some of NP-FW50 batteries. And I quickly discovered one thing. No matter which battery I have used: original Sony or third party one - I have never got even close to amount of pics they were said.
So during the years (about 10) I used original batteries as well as third party ones. And because I also discovered a huge difference in price between original and third party one - I started to use these last ones. I still have original Sony battery but I have increased my batteries reserve by 4 new third party ones bought directly in China what (including shipping) costed me pennies.
And because I also bought battery grip (also in China) I don't care about battery life anymore. I simply have 8 or 10 spares in my backpack and that's it. And one more thing: I have two chargers so charging takes not too long.
This is just my 2 cents.

Here's the graph for the test I did. I can't remember what the actual cut-off voltage was for the camera, but that affects the effective duration.If the cut-off is 6.7V or higher, the cheap batteries only show half the duration.

The solid blue line si the larger A58 battery for comparison, and the dotted line is the same curve with the time reduced according to the nominal capacity. You can see none of the NP-50 batteries perform as well as they 'ought' to do, and that is entirely due to the internal resistance.



Edited by Miranda F - 06 January 2021 at 17:07

addy landzaat wrote: <snip...> Companies like Wasabi of Jupio seem quite reliable. If you want to be sure, yes, stuck with OEM batteries. That is what I do, but third party batteries do not necessary be worse - but it usually are more expensive brands....

I have 3 sizes of batteries in rotating use: FM500, FW50 and FV70
Pretty bad experience with Jupio FV70 (life span, info an charging level), so I didn't dare to save some money on the FM500 and FW50.
But I am quite happy with my Nitecore USB-chargers.

At least one UK camera store (actual physical store) actively sells third-party batteries. And this is probably the only ones I would try - you could then point at the camera store if something goes wrong.

I was sold one fujifilm 3rd party battery and it reported about 80% charge when full (it was a lower capacity as per the label). I charged it once, put it in the camera, saw the 80% and sold it as 'used once'. Pointless saving in my mind. But then again - I don't shoot video and don't need 8x spares. Price is a big factor when you need that many.

Didn't one of the A7 series bodies ship with 2x cells in the box??