**Nitecore SC2 warning**

[striker42]

This is not a recall..................yet. Unsure of where would be the correct area to post, so I'll leave it here. Chrissie, Perpetua, snow, if you feel this post should be moved, then please feel free to do so.

From Mooch :
SAFETY ALERT: Nitecore SC2 charger overheating and failure

I am giving this charger a Do Not Buy recommendation. I was recently asked to help out with the investigation into the possible cause(s) of an accident involving a Nitecore SC2 charger and two cells from a major manufacturer.

18650batterystore sent me a new Nitecore SC2 to test and this unit failed in only three days of fairly heavy use. Luckily I was standing right next to the unit when I smelled something burning. It was then that I noticed that the charger’s display was blinking the eight-LED error “code” for both channels. I quickly unplugged the unit.

I do not know if the unit would have caused the cells to also fail if I wasn’t there to unplug it. Up until then the unit always smelled like “hot electronics” due to how hot it runs.

We do not know what caused the failure involving the other SC2 charger and the two cells yet. The charger was fairly new and both cells were new and were from a major manufacturer and purchased from a reliable vendor. Both cells ended up going into thermal runaway.

A teardown of the SC2 charger I tested showed that one component (a resistor) on a circuit board had blistered from excessive heat and another had failed completely, cracking into two pieces and actually melting the solder connecting it to the circuit board. There seems to be signs of excessive heat in other areas of the board too.

There is a small heat sink located on the other side of that circuit board, near the resistors, but since there’s almost no place for the heat to go the heat sink ends up getting “heat soaked” and becomes useless. This allows the temperature of the circuit board near those failed resistors to rise a LOT.

The high “local” temperatures near these failed resistors means they can’t handle the same amount of power as when their environment is at room temperature and the charger’s design needs to take that into account. Too often this is overlooked by engineers designing a product and could be the cause for these failures.

Or, Nitecore perhaps just decided that 2x2A charging isn’t done very often and that their resistors would last long enough?

In my opinion, if a charger automatically selects 2x2A charging then it should be able to charge as many times times as you want each day without failure. If there are components that get too hot for that then Nitecore should have added a temperature sensor near the overheating components so the charge can be stopped or the charge current lowered if necessary.

For the testing I charged two 2500mAh or 3000mAh 18650 cells at 2A each (the setting the charger picked automatically) seven to ten times each day. This is about 3-4 weeks of charger usage for a vaper charging once a day.

The charger’s outside temperature ranged from 75°C-85°C. This is ridiculously high, too hot to touch. The circuit board temperatures ranged from 90°C to over 100°C. The temperatures of certain components were much higher.

This is unacceptably hot. The high temperature of the bottom of the charger case actually warped the plastic matting on my test bench. Heat is an enemy of electronic components and the hotter a device runs the shorter, on average, its life is.

With all the chargers available to us there is no reason to take risks with our batteries. I recommend not buying this charger. If you already own one I cannot make any recommendations on whether it is “safer” to use it a lower charge current setting or with just one battery. I haven’t tested this Nitecore SC2 charger at lower current settings or with just one battery since the unit I had failed on its first round of tests.

If you are using this charger I strongly urge you to only charge on a non-flammable surface and to always remain nearby and awake.

Thank you 18650batterystore for sending me that unit for testing!

NOTE:
I do not have any charger recommendations I can make yet.
I cannot say if any other Nitecore chargers also have this problem yet.

[MrDJ]

been an update from Mooch

Deleted my SC2 failure post. I am ordering two more of them for testing to gather even more data and will post here when done. There was nothing wrong with the testing of the unit I had but I want mounds of absolutely overwhelming evidence now as it is clear that this is a really hot topic (definitely no pun intended). No more just “recommendations” though if any of the other two units fail, or even run as hot. Nothing we use should be able to boil water on its circuit board.

My testing, and any conclusions I come to, are never an indictment of your choice in chargers. If you love your charger, use it! If you have had no troubles with yours, fantastic! No one has to follow any recommendation I make.

But if a charger runs too damn hot, if one fails during testing, then the community deserves to know so they can do the same thing you have done...make their own choice as to which charger they want to buy.

[Perpetua]

Thank you gents for the initial information and further update . . . . I would think it makes sense to do some further tests on other Nitecore SC2 chargers, to assess better the overall safety situation with them.

[VapingBad]

Main thing if you have one don't leave it charging unattended until there is more info, Mooch is not panicking yet, but it is a caution. It does not age or harm your Li batteries doing several short charges, if you need to go to the shops or have a shower etc just turn the charger off until you come back.

[charliehorse]

I wonder if the resistors in the picture were correctly soldered on the board in the first place

[Chrissie]

Thank you from me also striker42 & MrDJ I'm more than happy for this for this info to stay in Product Recall.