"mike" wrote in message
news
On 11/14/2017 1:44 PM, Ian Field wrote:


"mike" wrote in message
news
On 11/14/2017 11:22 AM, Ian Field wrote:
Just curious about the failure mode - the cells really weren't worked
that hard.

Thanks.
You're gonna have to be a LOT more descriptive about the 'pack'.
passive/active/protected?
What did it power?

Just a bare 2P 18650 pack powering an e-cig with a 1 Ohm coil.

The only electronics is a power MOSFET where there used to be a
microswitch for the fire button.

Charging is controlled by a shunt regulator, there is a feed SB diode so
the shunt failing short can't harm the battery.

That seems to contradict the statement the the only electronics is the
MOSFET. I don't know what to make of that... And something has to
control the MOSFET


Yes - a tact switch salvaged from the front panel of a Sky box.

You're saying that the shunt regulator failing open can't harm the
battery?

It helps if you read before replying.

A shunt regulator failing short circuit (the most likely fault) wouldn't do
the battery any good at all - A SB diode in the feed makes that accident
unlikely.