Uplite, have you got any experience with the new Panasonic 3100mah 18650s?
I bought 2 to try out in my SC600 and so far they are absolutely fantastic. Only drawback is that they are unprotected, but the SC600 has built in protection already
Another one using these cells.
They're great cells that offer great VFM, only downside is they do not operate in my 1st generation SC600 without a magnet on the tip.
They do operate perfectly well in my H600 oddly enough though.
Actually...these little flashlights are one of the tougher consumer environments for a li-ion cell. In particular, they get dropped on the ground, thrown into gloveboxes or toolboxes, etc. That kind of physical shock can cause a thinner separator to fail, when a thicker separator survives.
I'm guessing you have never seen a radio controlled aircraft or car in operation then
It is actually extremely difficult to cause the membrane to fail, in the 10 years or so i've been using lithium based cells, the only times i have witnessed this failure are when a device has pulled too much current out of a cell (causing it to swell), a crash physically piercing the cells and when a charger has failed overcharging the cells.
Obviously this is not a apples to apples comparison as the cells are different.
But as long as the cell is physically protected (as when installed in a SC600) it would be extremely difficult to the point of impossible to have a membrane failure do to shaking or banging, simply because there is not enough movement internally in the cell to create enough momentum to cause it to tear.
It's also an extremely tough membrane (for obvious reasons).
I'm in no doubt Panasonic advise against throwing their cells around, this is just common garden *** covering.
In reality if the cells are discharged within their specs (to avoid failure from heat build up and/or swelling) charged within their specs (as before) and not physically pierced membrane failure is extremely extremely extremely unlikely.
The Panasonic 2900 and 3100 use the same chemistry, LiNiO2
At the risk of being pedantic it's actually LiMn2O4
The 3100 weighs slightly more than the 2900. So the only difference appears to be the thickness of the separator, which is very relevant to reliability.
The exact make up of these cells is a closely regard secret, so there is absolutely no evidence one way or the other to suggest the membrane is thicker of thinner in either application.
The higher capacity cells should be fine for fixed installations (e.g. solar arrays or electric vehicles). Lower capacity cells are more durable & reliable for rough usage (e.g. handheld flashlights).
As i say i'm using the 3100mAh cells and they work great in my torches :thumbsup:
Cheers
Mark
