SJ7 STAR BATTERY TEST

Discussion in 'Battery Tests' started by Troy, Apr 27, 2017.

  1. Troy

    Troy Administrator Staff Member

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    SJ7 STAR BATTERY TEST

    [​IMG]

    Let's start with a side story: After fully charging the SJ7 Star’s battery, I proceeded to do the first test attempt with the camera attached to the skeleton case, attached to the SJCAM Selfie-Stick and on a mini tripod. After around 15-20 minutes of recording, the camera was already so hot that I decided to abort it. I needed to keep the test environment safe for the camera and the Lithium battery. Besides, I also needed coffee.

    THE SETUP

    For the materials I need:

    SJ7 Star, our test subject
    Small shop fan to blow air towards the SJ7.
    Powerbank for resetting the battery to full should I need to repeat the process.
    I also prepared a damp towel just in case. And fixed myself a cup of coffee too.

    Alright, now for the settings:

    Resolution: 4K 30fps 16:9 - This is the maximum available recording resolution
    Loop Record: 3 minutes - To ensure that the last file is saved while others are kept safe for taking notes later.
    Screen Off: 1 minuteTo save screen time while simulating regular use
    Status LED: 3 – Just a visual indicator
    WiFi: Off – Not needed
    Auto-Shutdown: Off – We don’t want the camera to stop, remember?

    Everything else is irrelevant for the test purpose.
    Oh, and, the firmware that the SJ7 Star test-subject is on: FW1.09

    Here’s how the test environment looked like:

    [​IMG]



    We all know that 4K video recording requires A LOT of processing power and is sure to consume an equally large amount of battery power. As with any electronic device with heavy digital processes going on, heat will be generated and must be managed.
    Now, for the test, we need to find out how long the supplied battery can power the device at max settings. The 3.7V 1000mAh battery being tested is about 2 weeks old, with more than a dozen charge cycles in.

    LET'S BEGIN!

    Okay, so I removed the camera from the skeleton case and started the test, and as expected, the camera’s metal body acted as a heatsink to take out the heat from all that’s happening on the inside. It was hot after around 20 minutes but the fan is keeping the heat to a manageable level. I am expecting the battery to last around 40-45 minutes. Being so sure, I set up my phone to countdown 45 minutes.

    To my amazement, the 45-minute mark came and passed with the SJ7 Star still going! I tap the screen every 10 minutes or so, checking if the camera really is recording. I wipe the screen with the damp towel every now and then just so it doesn’t get affected by internal heat. But man, am I intrigued with every minute that passes!

    You ready for the results? Here:

    [​IMG]

    Yes, that’s 1 hour and 20 minutes.

    Total filesize is 27.5 Gigabytes.
    The Kingston 32GB card has enough to spare.
    Another thing to note is that the card is not even a UHS class. Just a regular Class10 microSDHC.
    And it was writing in full 4K!

    I must say I am very impressed. Good job SJCAM!
    Now I am curious if there are others out there who have tried testing it out too.
    Please comment your battery usage times below, just let us know what settings you have, estimated age of the battery, and what firmware you are running.

    Remember, this is a test. I allowed the Lithium battery to be fully discharged in the process, it should not be done unless you are aware that you may degrade battery performance significantly. Please charge your Lithium batteries before they actually die.

    -TF
     
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  2. Nguyen Luu Trung

    Nguyen Luu Trung New Member

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    I have a question. Can you somehow change the settings so the camera wont split the video into 3 minutes videos. Thanks
     
  3. Troy

    Troy Administrator Staff Member

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    @Nguyen Luu Trung @Alu:

    If your camera is splitting your footage to 3-minute segments, then you have the Loop Recording on and set to 3 minutes.
    You can turn this off so you can record much much longer footages.

    FAT32 will allow you to record up to 4Gigabytes non-stop.
    For 1080p 30fps footage, that's more than 1 hour before the camera will start to create another file to continure the recording.
     
  4. Philip Mars

    Philip Mars New Member

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    Hello people!

    What about SJ7 Star 1080 60fps battery life test?
    Are there any ways to extend battery life to 3 - 3,5 hours?

    Thank you!
     
  5. RBEmerson

    RBEmerson Humbled by events

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    Yes. Use an external battery. Batteries in the range of 50,000 mAh are readily available, from eBay and all of the other usual sources, and will give you somewhere around 5 - 5.5 hours on non-stop 1080@60 fps. BTDT

    If you're using the frame for the SJ7, a simple miniUSB to USB cable is all you need to connect to the battery pack. If you want a weather-tight case, buy the "motorcycle" (it works on bikes, skis, board, etc., etc.) case, with its own power cable.
     
  6. Philip Mars

    Philip Mars New Member

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    Thanks! Would 6,000 mAh be enough for 3 hours? The battery capacity itself is 1,000 mAh. Those 50k mAh powerbanks are to heavy for launching them to stratoshere, so 6k mAh weeights about 100g.
     
  7. RBEmerson

    RBEmerson Humbled by events

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    I take it you're putting an SJ7 in a balloon? I'm inclined to think 6K mAh won't be enough. But I've been proven wrong before.

    The best way to check out battery life is just fire up the camera and let it video until the battery goes. Easy-peasy.
     
  8. Jason

    Jason Moderator

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    Shush - I'm still testing a 5kmAh bank.
     
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  9. Jason

    Jason Moderator

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  10. Sulev Svilponis

    Sulev Svilponis Elite

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    I haven't tested, how about SJ7, but some other SJCAM cameras have problems when powered from some "intelligent" external batteries for prolonged time. Especially, when the internal battery is not fully charged. Then, after the connection is created, the camera starts charging from the external battery, and when the internal battery gets fully charged, the intelligent battery cuts the power and the camera will run on internal battery, until fully depleted - usually much quicker than expected.
     
  11. Troy

    Troy Administrator Staff Member

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    Funny thing about intelligent powerbanks and batteries. I have this big and heavy 20000mAh powerbank that's supposed to keep my device running, but like what Sulev reported, it did charge the internal battery and then let the internal take over, shutting off juice coming from the powerbank.
    Instead of kicking in as power is being consumed (internal battery), it didn't. Worse, lithium batteries hate going down to zero to the point that it can kill the battery completely. So now my battery won't take a charge the same way as before, often dying earlier than expected when used.
    I think the charging needs to be triggered again, or you have to unplug the USB then put it back in to start the cycle. Too late for me tho.
     
  12. RBEmerson

    RBEmerson Humbled by events

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    There may be battery packs that shut down after charging a device (phone, tablet, camera). I've never seen one, but that just means I've never seen one.

    Um, actually discharging a lithium battery does not kill it. Yes, there may be a slight loss of capacity, but it also cleans up (poor analogy but the details are not needed here) the battery, meaning it can be fully charged, instead of stopping acceptance something less than 100%. In short, rarely pulling a lithium battery down won't hurt it. Doing it regularly - not a good idea.
     
  13. RBEmerson

    RBEmerson Humbled by events

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    @Troy You're describing one of the problems with the SJ7: poor power management. Done right, if the internal battery can power the camera, it should do so, of course. If an external power supply can power the camera. It's the transition from one source to another that causes problems. There's no need for the camera to shut down as long as anything, internal or external, can power the camera. As it is, now, any change shuts the camera down.
     
  14. Jason

    Jason Moderator

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    Well, I disharged half the camera battery them plugged in the second power pack and started the video. That was 45 minutes ago so the battery has managed to charge in the camera and keep running.
     
  15. Troy

    Troy Administrator Staff Member

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    That may also be correct. The SJ7 would shut itself down once you unplug it from a power source. I'll add that to the wishlist.

    About discharging, Lithium isn't really happy when totally discharged. The membrane that sits between anode side and cathode gets weak.
    Specially when storing for long periods of time, I suggest at least 40 to 50% charge kept in.

    Luckily, I have this experience with a pair of 18350 (cylindrical. obviously not an SJCAM battery, but works as an example here) that are more than 3 years old.
    One was left with very little charge, it appears, as I can't charge it as much as the other one. The other one is very healthy, holding a 4.2V charge like it hasn't aged that much.
     
  16. RBEmerson

    RBEmerson Humbled by events

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    I haven't really pushed hard on testing but... V1.21 seems to allow hot plugging in external power (Yea!!!) but not removing external power (wonder why). The camera is powered up, an external battery pack is plugged in, the camera stays up - Good Thing.
     
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  17. Damian Holt

    Damian Holt Moderator

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    The shut down on external power loss is also an issue with the M20 and the 5000x elite.
     
  18. Troy

    Troy Administrator Staff Member

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    The guys over at firmware development are finalizing that. Hopefully seen in other models' firmware.
     
  19. RBEmerson

    RBEmerson Humbled by events

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    Not found in V1.21r3 put out on 30 Jan.
     

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