2nd Gen Prius PHEV Conversion (Enginer plug-in lithium ion battery kit)

[Daox]

I'd say it definitely lowers the priority of building my own EV. If I can maintain around 100 mpg I'll use a bit more than an 1/8th gallon of gas a day. Assuming no other driving, that allows for 2 months between fill ups.

However, you know I just got an AC motor controller so... its still on the list of things to do...

[Daox]

I got to use the kit one more time last Friday. I was on my way to work and was a few hundred feet from the parking lot going down a 25 mph road and I started to smell something. I shut the kit off and haven't been able to take a look at anything yet, but I know its the dc to dc converter. The light on the switch panel doesn't light up anymore. I'll be removing it soon to see what happened.

[mrbigh]

Originally Posted by Daox

I got to use the kit one more time last Friday. I was on my way to work and was a few hundred feet from the parking lot going down a 25 mph road and I started to smell something. I shut the kit off and haven't been able to take a look at anything yet, but I know its the dc to dc converter. The light on the switch panel doesn't light up anymore. I'll be removing it soon to see what happened.

I guess that the Enginer's gremlins are acting up againnnnn

[Daox]

My guess is that with 2kwh vs 4kwh I had more voltage sag than normal. To put out the same power, it had to draw more amperage from the pack and that lead to heating and toasting of something.

[Daox]

I popped the cover off the converter tonight and found what I think is the bad component. It looks like it over heated. The fuses all look fine.

[mrbigh]

Originally Posted by Daox

I popped the cover off the converter tonight and found what I think is the bad component. It looks like it over heated. The fuses all look fine.

Actually, that's a 100% component fairlure . In manufacturing we called it
MTBF (Mean time between failures).
Many factors for this rupture but it can be credit to low quality components.

[MetroMPG]

Are you talking about the black capacitor looking bit? Did it spew that goop out of it as well?

[Daox]

Nah, the white stuff is just glue or something to keep components in place. The discolored mosfet looking thing is the toasted one.

[Xringer]

I see a transistor type package (TO-220?) in the middle that has some rusty look to it.
I assume that's the device that failed.

Question, is the steel bar holding the package down real tight??
It's hard to tell from the pic.. If that device isn't being pressed down hard, that could be why it failed.

TO-220 Transistor Dual Heatsink Clamp

Edit:
Using Zoom, it looks like 1/4 of the ceramic top of the package has blown clean off.
That thing must have been HOT!
The Clamp seems to be offset a bit on the left, not lined up like the others.

[Nevyn]

Those MOSFETS are nice and square in relation to each other...looks to me like they were soldered poorly and not heat sinked enough.