Grid Charging Outdoors - Heat Issues?

[Mike Dabrowski 2000]

Art,
Get an indoor outdoor thermometer, $8 at Wallmart automotive section.
Install the outdoor probe so the inlet air to the pack passes over it,(Duct behind passenger seat) Set up the display so the exhaust air blows over it, and you will be able to monitor the temperature rise of the pack, and the temp differential across the pack. If you see temps over 120F, consider charging when it is cooler. That way you can answer your own question. If the car is over 120, it is probably not a good time to even start the process.

[Artric]

I'm definitely going to be wary of charging in the sun. Yesterday I set it up to charge, took a nap and found my temp gauge sitting next to the charger reading 150F!!!

It was pretty much in direct sunlight in the heat of the day. Who knows how hot the pack got. What are the chances of doing significant damage given the fact that it was this way for probably a couple of hours?

[uhtrinity]

According to the data I collected from the PTC strips the system cuts off at 150F with a P1449 (overheat). I lowered mine to 130 - 135F. Anything above 140F scares me.

Again, I never plugin charge in the sun 8^) <----- sunglasses

[Mr. Mik]

Originally Posted by uhtrinity

According to the data I collected from the PTC strips the system cuts off at 150F with a P1449 (overheat). I lowered mine to 130 - 135F. Anything above 140F scares me.

Again, I never plugin charge in the sun 8^) <----- sunglasses

In the NHW10 Prius each half-pack has a 300 Ohm resistor is series with the PTC strip. That should have a similar effect, but I have no idea if the circuit that interprets the resistance measurement uses the same decision making process as in the Insight.

What value resistor did you add in?

I guess Mark's battery would have been at less than 65degC (150degF) because it was lagging behind while being actively heated by the "cooling" air! At 350mA the battery produces very little heat unless some (or all) cells are already full.

Mik

[Mike Dabrowski 2000]

There is a tag on the door sill that warns that the NIMH battery can be damaged if the car is heated to >145F to cure the paint during body work.
If the outlet air from the fan cooling the pack was at 150F, you could have damaged your pack.
Why did you charge it in the sun? That was not very smart after all the discussions about the need to cool the pack during charging.
The effectof overheating the cells is that the internal pressure in the cells increases and causes electrolyte to vent out of the positive terminal of the cells, potentially causing permanent reduction in capacity and increase in internal resistance.
Good luck, hope it is ok.

[uhtrinity]

Originally Posted by Mr. Mik

In the NHW10 Prius each half-pack has a 300 Ohm resistor is series with the PTC strip.
What value resistor did you add in?
Mik

I calculated approximately 250 ohms to give a 130F cutoff. The cutoff is in the form of a P1449 code which kills the main HV relay.

PTC Strips

[Artric]

Originally Posted by Mike Dabrowski 2000

There is a tag on the door sill that warns that the NIMH battery can be damaged if the car is heated to >145F to cure the paint during body work.
If the outlet air from the fan cooling the pack was at 150F, you could have damaged your pack.
Why did you charge it in the sun? That was not very smart after all the discussions about the need to cool the pack during charging.
The effectof overheating the cells is that the internal pressure in the cells increases and causes electrolyte to vent out of the positive terminal of the cells, potentially causing permanent reduction in capacity and increase in internal resistance.
Good luck, hope it is ok.

I actually meant to do it as a test, which is why I put the thermometer in there. But then I took a nap and didn't mean to leave it unchecked for so long.

I've fully charged it and used the charge since. It seems to be working just fine. I doubt it really was a full 150F in there. The thermometer I had is in a black plastic casing (the temp sensor is inside) so it probably collected heat, where there was a full 12v fan across both the charger and the pack.

So for summer, it looks like it's just evening and overnight charging for me!

[Hybrid-Battery-Repair]

[QUOTE=uhtrinity;169455]I calculated approximately 250 ohms to give a 130F cutoff. The cutoff is in the form of a P1449 code which kills the main HV relay. [QUOTE]

Remember that's for any ONE cell. It is designed to trigger if one or more overheat. If he overheated the whole pack, it was probably more like 30K ohms.