Have you ever wanted to own an electric car? or have you ever wanted to drive a Porsche 911? I wanted both, so I decided to build one. This blog is here to document my journey as I convert a 2002 Porsche 911/996 Carrera 2 from a gas guzzler to a completely electric vehicle - not a hybrid!

Sunday, June 16, 2013

Resistance update

I set aside two solid days to put the car back on jack stands and remove the front battery packs (cells 24-48) in order to disassemble, clean, and reassemble all the bus bar contacts.  What I've learned from studying the data from the BMS is that all the inter-pack bus bars that were pre-assembled by GBS/ElitePowerSolutions are poor quality.  After I got them all back into the car, the first test drive showed a reduction of about 24mOhms for those cells which cut the previous resistance in half!  The change was noticeable while accelerating, the pack overall voltage drop is less and the total available amperage is higher -- so now I've added cleaning all the other cell bus bars on my to-do list.  The good thing is they are much more accessible(no jack stands required) from the back of the car.

While under the car, I also repaired the rest of the wiring for the Kats tank heaters and new coolant pump.  I'm glad I did this because during testing, I found out that one of the Kats heaters was burned out from the "incident" after the rainstorm.  I replaced that while I had easy access under the car.

Overall, good progress.  I've also been researching ways to add cold air conditioning to the car.  I'm looking at HEV A/C compressors.  Once I find the right solution I'll post more.

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