SJ7 Warped and Deformed

TeriTerryTarry said:
Not likely, right?
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I'm not sure, 29 degrees C is not excessive, it is less than blood temperature, in some places it is quite cool for summer temperatures!

Also their response says that it shuts down if too hot, and even if it doesn't the power spec is for only 1A max, which is only 5 watts which isn't all that much heat, especially for a metal case.

It's not even a black front that would have absorbed the heat of the sun, being silver it should have reflected the sun's heat!

Most likely they have used some very low temperature plastic for the front panel and they are all like that. Their other cameras, like the SJ6 have a rubbery plastic so maybe they don't have experience with the stuff they used on the SJ7 and didn't think of testing it before launch.
 
Yep, 29°C is not excessive at all. Last summer we had temps reach 39°C. With the windows rolled up and the vehicle parked in the sun I'm sure it got up to 60°C or more inside. My SJ4000 and Elephone Explorer Pro were exposed to direct sunlight at that temp and never deformed.
 
Nigel said:
Also their response says that it shuts down if too hot
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I'm not entirely sure about that. What they actually said was, "The camera's electronics use a protection circuit that cuts off power when it reaches dangerous levels." When what reaches dangerous levels? I suppose in context they mean temperature but it's not really clear. And if they did mean temperature then temperature of what? What's the upper set point? Operating temperature of the electronics? Remember the camera continued to record so apparently that temperature was never reached. The temperature of deformation of the plastic? That was obviously reached and breached. The whole thing just is not that clear to me.:confused:
 
TeriTerryTarry said:
And if they did mean temperature then temperature of what? What's the upper set point? Operating temperature of the electronics?
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The battery. You protect the battery first or will go kaboom.

Li-ions batteries have a BMS/Protection IC in them for over current, over charge and over temp protection. If you crack open a li-ion battery you will find a tiny board like this crammed in there.

Since you removed the battery you took the temp protection with it. That's why they don't recommend using power banks per se.
 
flip9 said:
The battery. You protect the battery first or will go kaboom.

Li-ions batteries have a BMS/Protection IC in them for over current, over charge and over temp protection. If you crack open a li-ion battery you will find a tiny board like this crammed in there.

Since you removed the battery you took the temp protection with it. That's why they don't recommend using power banks per se.
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Ah, this is confusing. Does it make any difference if the over temperature condition is due to the environment (the sun beating down on it) rather than operation of the camera at 4K? In a separate e-mail SJCam "very strongly advised" that the battery be removed when operating as a dash cam. It seems like a catch-22. To protect the battery from over temperature you remove it. But you need it to protect the camera itself from over temperature. I did verify with SJCam that it's okay to use power banks. Would it be any different using a DC adapter vs a power bank? Also the camera presumably never reached an over temperature condition because it continued to record the whole time and none of the files were corrupted, although with the battery removed and over temperature protection along with it, how would one know for sure. Only the camera face was deformed.

Perplexing!:confused:
 
The camera will have a separate temperature sensor, I assume built into the processor and it should power off if too hot even if there is no battery.

Turning off can't stop the front getting hot if you place it in midday sun in death valley, but cars are built with plastics capable of withstanding such conditions so a camera designed to operate as a car dashcam should too!
 
Nigel said:
The camera will have a separate temperature sensor, I assume built into the processor and it should power off if too hot even if there is no battery.

Turning off can't stop the front getting hot if you place it in midday sun in death valley, but cars are built with plastics capable of withstanding such conditions so a camera designed to operate as a car dashcam should too!
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Yes, this is the thing I'm trying to understand. To me the failure seems to be the plastic front. Over temperature protection of the camera does not seem to have failed because it continued to record and the files weren't corrupted. In other words, the camera internals never got too hot. It's just that the plastic front warped.
 
TeriTerryTarry said:
Perplexing!:confused:
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Indeed. At first glance of the pics i thought something went very wrong like a swollen battery.

The warping seems quite severe for a 29c day. Plus pink doesnt absorb as much heat as black.

Either the plastic is really crap or the cam kept running full pelt in cabin heat or both.

Perhaps grab the pliers of knowledge and pop the face off?
 
flip9 said:
Indeed. At first glance of the pics i thought something went very wrong like a swollen battery.

The warping seems quite severe for a 29c day. Plus pink doesnt absorb as much heat as black.

Either the plastic is really crap or the cam kept running full pelt in cabin heat or both.

Perhaps grab the pliers of knowledge and pop the face off?
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I assume that it got too hot inside, not just on the front, because the battery compartment is too warped for the battery to go back in. Suggests that it didn't turn itself off soon enough for the plastic to survive.

I was going to suggest pulling the front off too, but I guess it should go back to SJCAM as it is for them to investigate, unless they are all doing this in which case they wont want it back!
 
Here's what it looks like inside. My thoughts about the battery compartment are that the warped front caused other stresses in the camera that resulted in things getting bent out of shape. I don't understand how it got too hot inside when it continued to record during deformation and none of the files were corrupted. Still you could be right. I just don't know.Inside 1.2.JPG Inside 2.2.JPG
 
Why have they covered everything in plastic insulation to stop the heat getting out o_O
 
That would be a reflector/RF shield for the antenna. This prevents interference with the other electronics on the board.
 
I received some encouraging news from SJCam on this issue. In an e-mail they said the following:

. . . we will be looking into changing our faceplate material and ways to improve ventilation to prevent this from happening again.
We have also updated our manual warnings with several notes about use as dashcam and under the sun.

This is a welcome development. I appreciate SJCam making an effort to address the matter.
 
TeriTerryTarry said:
I'm not entirely sure about that. What they actually said was, "The camera's electronics use a protection circuit that cuts off power when it reaches dangerous levels." When what reaches dangerous levels? I suppose in context they mean temperature but it's not really clear. And if they did mean temperature then temperature of what? What's the upper set point? Operating temperature of the electronics? Remember the camera continued to record so apparently that temperature was never reached. The temperature of deformation of the plastic? That was obviously reached and breached. The whole thing just is not that clear to me.:confused:
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The 4K mode always cause more heating.
I noticed in early version, it support charging while recording, then in new FW version, disable charging while recording on SJ7.
Normally to avoid such issue, the camera will stop charging while the temperature reach the specific value. I thought this is what the mean about the protection.

Anyway, the heating issue is a challenge for most of manufactures which use Ambarella chipset.
 
We are working on a solution for this. Our later documentation will reflect more warnings and upgrade to build.
 
TeriTerryTarry said:
I received some encouraging news from SJCam on this issue. In an e-mail they said the following:

. . . we will be looking into changing our faceplate material and ways to improve ventilation to prevent this from happening again.
We have also updated our manual warnings with several notes about use as dashcam and under the sun.

This is a welcome development. I appreciate SJCam making an effort to address the matter.
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Swiss cheese version with metal front, super capacitor and instructions to never use in sunshine coming up... :coffee:
 
The git guys were former partners with us and were here before I was. I think the FW solution may be best. Materials and ventilation, and yes, manuals are being updated. Thanks guys for your input.
 
Nigel said:
Are you going to do the same test on the replacement?
Or just declare it unsuitable for dashcam use?
Maybe get a thermometer and monitor the actual in-car and out-of-car temperatures next time, start off in the cool of the morning and see how close to mid-day it can cope with. Get another camera to watch the front cover warping in timelapse.


It's being sold as a 4K camera, why would you use anything else?
If we only want 1080 we have plenty of choice, no need to pay extra for a 4K camera that overheats.
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We are waiting for all issues to be fixed before sending replacement/ review units.

The faceplate material will be upgraded and possibly more ventilation holes. We are also checking into several other things such as firmware as well. Again, out of maybe 30k units sold, Teri's report was only the second one. So, hopefully, it was just a case of a bad component/powerbank+battery under the sun....

We are getting there guys. Thanks for you help and patience.
 
sjcam_official said:
We are waiting for all issues to be fixed before sending replacement/ review units.

The faceplate material will be upgraded and possibly more ventilation holes. We are also checking into several other things such as firmware as well. Again, out of maybe 30k units sold, Teri's report was only the second one. So, hopefully, it was just a case of a bad component/powerbank+battery under the sun....

We are getting there guys. Thanks for you help and patience.
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I will reiterate, AGAIN, that the battery WAS NOT in the camera at the time the faceplate deformation took place. It's important that you understand this because if you undertake changes to hardware/firmware/manuals based on conditions other than the actual conditions then one can only wonder if the changes themselves will work correctly.
 
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