What actually goes wrong with the batteries????
Battery packs exposed
Keeping Warm In New England
Plugging into the SUN
Making a small solar concentrator
Building MIMA and the plug in adapters
Converting a telephone truck to electric
DIY dual pulse Capacitor Discharge Spotwelder
Replacing gasoline with solar electric lawn equipment
Tapping into the Wind
Expanding MIMA with the Distribution board ( users projects )
How to stop the aging process DIY
What is Genesis One?
MIMA Install Day 2005 a Big Success!
Building a hybrid car grid charger
Assembling the bases
building it bigger 4.5A
Calibrating the temperature
Calibration and test of components and boards
Charger # 1 goes into beta testing
Discharger # 1 / gridcharger cycler accessory
Fan and temp boards
Getting serious
Harnesses for the Insights are nearly finished
Helpers make it go much faster
Inside the overnight charger
Modified overnight boxes
More thermal testing
Moving towards the goal line
PTC strip monitor and charger shutdown circuit
Temp volts and current calibration fixture
Test of accuracy
The code
Thermal testing.
The weather slows us down

Thermal testing.

Thermal testing.
charger testing at full output

Set up a big load for testing the chargers. Test one with no fan showed a nasty 140F inside the charger case, so I mounted a 40mm CPU fan rated for 4.9CF/Min on the box and have run a second test.
After 3 hours at full output, we are at a much more reasonable 102F in the box. The big heat sink on the other hand is at 130F, even with a 4" fan blowing on it. 500+ Watts in the closed battery box would definitely cook some cells, or worse yet if one cell had high internal resistance, it would dissipate much of the wattage, and get very hot.
PTC and inlet to outlet temperature monitoring will keep things safe even in worse case conditions.