I bought a new battery for my camera assuming that it would be enough to be compatible, in Sony terms "NP-FW50". Though I think the generic is better than the original:

  • Generic: 7.4V, 1950mAh, 14.4Wh
  • Original: 7.2V, 1020mAh, 7.3Wh

I believe higher mAh means it holds more power for longer.

So, is the generic better than the original? Or am I completely missing the point?

  • It's certainly better on paper. The question is: how much can you trust the paper? – Please Read My Profile Jul 31 '14 at 20:07
  • Possible dup: photo.stackexchange.com/questions/1339/… – MikeW Jul 31 '14 at 20:39
  • A couple of items to consider - Even if the current performance is better, the quality of the materials my vary from expectations. Consequently, it may start to degrade over time. - Secondly, sometimes the brand company outsources manufacturing of the item to a contract mfg. In some cases, those contract mfgs may sell a generic version. Ultimately, unless you want to disassemble the battery, it's hard to tell if you are getting a bargain or dangerous counterfeit. – B Shaw Aug 30 '14 at 21:59

I and others have answered those questions fairly well here ->
Should I buy an original manufacturer battery, or is a generic brand OK?.
I just looked through my prior answer and I think it covers the subject fairly comprehensively.

A couple of specific points related to your questions:

(1) Clone batteries often claim higher or much higher mAh capacities than genuine originals.
While in some cases modest gains in capacity MAY be genuine, very large ones invariably are not, and a clone battery will usually have a lower capacity and shorter operating life than a genuine one.
This does not mean that they are necessarily lower value-for-money - see my answer cited above for more detail - often the overall cycles x mean capacity / Purchase_price will be better or even much better for a clone. I would tend to avoid clones that claim substantially higher ratings than original batteries as, once a vendor is willing to label batteries with manifestly incorrect technical data their integrity and all other claims are suspect.

In this case the 91% increase in capacity from 1020 mAh to 1950 mAh is in-credible.

As opposed to clones there are outright fakes such as
Update on fake NPW-50 and
(You Tube 3m-19s) How to tell if yourebay Sony battery is fake

You might think that a fake-maker would try to do a good job so that they can commend a high price and continue to be able to sell product, but the usual experience is that fakes are bad or very bad performance wise.

(2) The 7.4V versus 7.2V claimed difference in voltage is meaningless. Lithium Ion cells have a fully charged voltage of 4.2V and voltage at end of discharge is about 3V (set by low voltage cutoff in equipment). The "average" of 3.0 and 4.2 is (4.2 + 3.0) / 2 = 3.6V. However, the discharge curve is not linear and actual voltages are affected by load current so stating 3.7V or 3.6V as average voltage means nothing. 3.7V is arguably closer to the average for a lightly loaded cell but 3.6V is probably more commonly used.

Update - April 2015:

I just bought 3 x clone batteries for a Sony A77. They all worked OK at first but after 5 to 100 photos taken all 3 cause camera to give a "incompatible battery message. I have used MANY clone batteries with a range of Sony and a few other cameras and never before seen this happen.


Yes, the generic one has more capacity, if these specs are correct. It delivers a fractionally higher voltage though, not sure if this could cause problems.

  • It would have if they were but they won't be so it hasn't :-). The stated voltage is an approximation to the average for 2 LiIon cells in series and both are close enough to correct to be unimportant. – Russell McMahon Aug 31 '14 at 2:16

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