OMD EM5 spare battery (where to get it?)
- Thread starter skeletonman
- Start date
NazgulKing
Senior Member
Out of technical curiosity, is the difference between linear voltage regulators like the L78* and L79* series or the adjustable ones and switching regulators like the chip you mentioned such that the switching varieties have some kind of voltage sensing function to keep a stableI see that a number of you are thinking of getting third-party batteries for your E-M5 and some of the e-bay deals are really tempting based on the price differential. An original battery costs around SGD100 at the moment in Singapore and e-bay seller DSTE is selling three-batteries for USD35. No matter how you look at it, it seems to represent quite a large savings. So, the question is if this is the real deal? Well, I set out to find out the answer, and to some other questions as well.
When I saw the e-bay deal, I grabbed the last (or second last) available set for at the aforementioned price. Shortly thereafter I received a message from the seller stating that the battery cannot be charged with the original charger and so they're throwing in their own charger for free. "Fair enough" I thought - and after just about a week the package arrived. Three batteries and one charger. Both the batteries and the charger are "DSTE" branded.
Okay, so far so good. The battery is exactly the right sized and fits and actually works in the camera. [Both the DSTE and the Olympus batteries weigh in at exactly 50g.] The charger looks interesting - charges with a bi-color LED that goes red/orange during charging and turns green at the completion of the charge. For those who are interested, the charging circuitry is quite interesting, using an MC34063 switching regulator with an opto-coupled mains feedback loop. The open terminal voltage is 8.4V which is about right for Li-Ion 2S cells. The charger also has a rather interesting design where the mains connector swivels out, saving some space. The internal design of this raises some reliability questions in the long run.
Putting the battery into the original charger fails to initiate charging, as expected. This is presumably due to something going on with the "T" tab, which is used, presumably, for temperature sensing. Other than that, so far, things seem to be working.
Now, the e-bay page:-
3PCS DSTE 7.6V 1450mAh BLN-1 BLN1 Battery Pack for Olympus OM-D E-M5 EM5 Camera | eBay
makes several claims about this battery. Namely that this is made of "100% A+ Sanyo Battery Cell; Real Capacity" which is indicated as 1450mAh on the battery itself and visible in the photos. [Note: Original Olympus is rated at 1220mAh.] Okay, so I decided to do some dissection here to see what is exactly under the hood. Here's what it looks like:-
What is most significant, however, are the cells themselves. They're 1020mAh cells, and do not appear to be Sanyo made either:-
The cell type is RHD633443ART1020mAh made in April 2012. These appear to be made by Zhongshan Tianmao Battery company in China - most definitely not Sanyo. So these batteries will only hold 84% of the charge of a real Olympus 1220mAh battery. (Assuming you get 250-shots out of an original battery, this will give you 209-shots before it gives up on you.) It is also only 70% of the claimed 1450mAh.
Apart from the cells, there appears to be some kind of protection and cell voltage balancing circuitry in the top PCB inside the battery. This is a good sign, meaning that the battery should stay balanced and deliver reasonable performance within the discovered specifications (1020mAh, and not 1450mAh as labelled, or 1220mAh of the original battery).
Update: I have cycled the cells through an analyzer and they measure around 1001mAh, which is close enough to 1020mAh when discharged down to 3.2V. Probably with more use, the capacity could improve slightly towards the rated capacity. This means that the cell rating is correct at 1020mAh and not better as hoped by some optimists.
Moral of the story - you get what you pay for. The DSTE batteries may still represent some value since it is far cheaper than an original battery. The total capacity of three of these batteries is 3060mAh, for about about SGD47 or 47% of the cost of an original battery.
There - you're the first to hear this breaking news! I have also made some other tests but will leave that to another post.
Daniel Wee
voltage?
Daniel Wee
Member
Linear regulators rely on power shunting to control excess voltage. If the supply and target voltage differential is high, this will result in high power dissipation, which will mean a hotter running device. Linear regulators, however, are generally less noisy electrically. Switching power supplies are far more efficient under most circumstances but tend to be more complex, have more components, and are more noisy compared to linear regulators. The noise can be controlled, however, with good design. Lastly, for mains power supplies, switching designs can be made considerably smaller due to the lack of a huge power transformer. Both types of regulators serve their specific purposes and which is best really depends on the particular application.
Daniel
Daniel
esoeij
Senior Member
Just went to SLR Revo, Alan Photo, TK Photo,
Artworkfoto, Cathay Photo at Funan area. All of them said the battery is out of stock.
I was just at Artworkfoto at lunch time and there were still a few batteries left. I didn't buy cos $95 is a bit steep and I don't need it urgently.
Daniel, great stuff you are doing with the 3rd party battery. I got one myself and was delivered to me yesterday.
The eBay seller stated that the charger would work with the original battery, do you think his claim is genuine? Would you pop your original battery into the 3rd party charger to charge?
The eBay seller stated that the charger would work with the original battery, do you think his claim is genuine? Would you pop your original battery into the 3rd party charger to charge?
Daniel Wee
Member
KTi,
Yes, it looks like the charger should work but I have not tried it on the original battery yet. No technical reason why it should not work though.
Daniel
Yes, it looks like the charger should work but I have not tried it on the original battery yet. No technical reason why it should not work though.
Daniel
Hi Daniel,
Thanks for sharing and it seems you are very knowledgeable in this area and hope you can help me with some queries on the 3rd party battery. I just bought a 3rd party battery yesterday for my GX1 and the battery said "7.4V 2800mAh" while my original battery is "7.2V 1010mAh".
I inserted the battery into my GX1 and it worked and showed full bar. But I am a bit worried so i fully charged the battery using my original charger which took two hours. Then I also fully charge my original battery. This morning, I brought my two batteries to the office to test using a multi-meter. The 3rd party shows 0.9V(???) and the original one shows 8.54V.
Here are my questions:
1) The mAh may not a problem but the 7.4V which is higher than the original 7.2V made me worried. Is it a concern?
2) Is my 3rd party battery spoilt? I dare not charge it or put into my camera to try further.
3) Do you think it is safe to use 3rd party battery?
Thanks in advance.
Thanks for sharing and it seems you are very knowledgeable in this area and hope you can help me with some queries on the 3rd party battery. I just bought a 3rd party battery yesterday for my GX1 and the battery said "7.4V 2800mAh" while my original battery is "7.2V 1010mAh".
I inserted the battery into my GX1 and it worked and showed full bar. But I am a bit worried so i fully charged the battery using my original charger which took two hours. Then I also fully charge my original battery. This morning, I brought my two batteries to the office to test using a multi-meter. The 3rd party shows 0.9V(???) and the original one shows 8.54V.
Here are my questions:
1) The mAh may not a problem but the 7.4V which is higher than the original 7.2V made me worried. Is it a concern?
2) Is my 3rd party battery spoilt? I dare not charge it or put into my camera to try further.
3) Do you think it is safe to use 3rd party battery?
Thanks in advance.
116520
New Member
I will not save ~$50 to risk killing my camera... on the other hand, there are people who don't mind paying more for extended warranty which I find it useless...
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