[Swordmaker]

Do you think the Samsung battery problems were due to sloppy design/checkout? Poor battery supplier choice, and poor quality controls? Poor internal qualification procedures at Samsung? Or did Apple just dodge a bullet, and it could have happen to them also?

Frankly, I think that Lithium Ion batteries do not respond well to rapid charge cycles as well as Samsung and other Android makers think they do. I think the process causes internal changes that may make them susceptible to rapid overheating on discharge. This rapid overheating can be exacerbated by slight physical damages during construction or even pressure on the battery case which may precipitate an arcing inside the battery case. Slow trickle charging does not precipitate this overheating. Fast charging does.

The normal, expected failure rate in Lithium Ion batteries is one in 8 million per year, yet these Samsung devices were failing at about 250 per million per month, or ~3,000 times that normal rate.

Apple has deliberately chosen to not implement rapid charging for a reason they will not go into to. . . I suspect this is the reason.

[El Cid]

Thanks - that is an interesting perspective, and sounds very plausible.

[GRRRRR]

The article I read on CNET?, I think said they wanted better battery life by putting an extra layer or two of cells. The additional compression on the battery stack caused some fatigue at the connection terminals.

The fatigue was causing pinholes in that area allowing the liquid electrolytes to leak and short out.

Regardless, I would have expected bench tests to find this defect...