On Thursday, April 5, 2018 at 8:14:21 PM UTC-7, jfitch wrote:
On Thursday, April 5, 2018 at 10:20:48 AM UTC-7, Richard Pfiffner wrote:
On Thursday, April 5, 2018 at 8:04:40 AM UTC-7, Tango Eight wrote:
On Thursday, April 5, 2018 at 10:52:17 AM UTC-4, Richard Pfiffner wrote:
On Wednesday, April 4, 2018 at 10:16:45 PM UTC-7, kinsell wrote:
On 04/04/2018 04:04 PM, Richard Pfiffner wrote:
On Wednesday, April 4, 2018 at 2:31:07 PM UTC-7, kinsell wrote:
Wow. Didn't these batteries have a battery management system to prevent
damage?



On 04/04/2018 03:22 PM, Richard Pfiffner wrote:



John,

My experiences with LiFePO4

I have never heard of a LiFePO4 battery catching fire. I have had some customers connect reverse polarity. It burnt up the internal positive wire but the battery did not burn. I also just shorted a LiFePO4 12V10Ah turned it upside down and placed on a metal plate. It got hot and distorted the case near the contacts for the cells. It did not burn and was cool when I looked at it 1/2 hour later.

I had one supplier that gave me 24 Volt chargers by mistake. I charged one battery overnight and it got very large but did not catch fire.

Richard
www.craggyaero.com


I have found that BMS will not save a short.

Richard
www.craggyaero.com


A good short should bring the terminal voltage below 10 volts instantly,
strange the BMS didn't kick in before damage occured.

Also a bood BMS ought to prevent overcharging , which clearly didn't
happen with the 24 volt chargers. If I had a battery swell in my
ASH-26E, it would cause some significant damage.

The overcharging was a Stark Battery.

I will try the short on the famously expensive K2 battery today.

Standby for results.

Richard
www.craggyaero.com

Need video :-).

T8

Video shows nothing battery gets hot and cuts out at I suspect about 10V.

Richard
www.craggyaero.com

Richard, try dropping a similar sized SLA on a metal plate.

I suspect a fire or at least a lot hotter.

Richard.