Mark 3

Lately I havent been driving the car much and I realize it's for a few reasons - 

1. I have a bad cell (#23) that limits the range. Everything will seem fine and then this one cell will drop to below 3 volts, shutting the car down. It's back to 20 mile range, which isn't horrible, but it's a nuisance. 

2. Sometime after the last clutch replacement, the throwout bearing failed. It makes a horrible noise when engaged and I'm thinking it could catastrophically fail, which would be a problem... 

3. The controller is running too hot. My passive cooling systemm using a transmission cooler without fans isn't cutting it. 

4. Public charging takes way too long. At home I can charge it overnight and all is well, but if I need to charge it out in the wild, the charger just can't produce enough current to charge the pack in an adequate time. 

5. Manual steering is getting to be a real hassle. It was workable when it was a commuter car - I parked in a parking lot, but now as a city car I have to deal with parallel parking - sometimes backwards uphill. Power steering would make the car much more useful. 

So while searching for replacement CALB cells I noticed the price of new cells has dropped significantly. I had thought about using a Tesla or other wrecked EV pack, but I was worried about doing something stupid with an unforgiving battery chemistry. I wanted to stick with LFP (or LiFePO) cells, since they seem more resilient to user error. Furthermore, I didn't want to rebuild the battery racks if I could help it and I am limited to 156v Nominal by the Zilla 1k I'm using. If I go above that I would need to change controller and likely the motor. 

And so...

Pulling the motor exposed what was left of the throwout bearing. It was a twisted mess and surprisingly worked at all. Didn't get a picture though...

I found I had room to fit EVE 280ah cells, but only 46. I had to modify the nose rack to accommodate 14 of these since they are quite a bit bigger. I had a little extra space in the racks with the CALB cells, that's all gone now.

 

With the added amperage of the new pack, the charging problem would be much worse. I rewired the J172 to use 10 gauge wiring and was able to get a new air cooled 6.6kw charger just before the new Chinese tariffs kicked in.

It was a tight fit but all good.
 

I found a PC cooling kit that would fit my front grill area nicely. It came with 3 fans with LEDs that glowed different colors. Not really my style, so they got painted black. 

Another thing that's been bugging me is the temperature gauge on the dash. It's way out of scale for the temperature of the controller. You can't tell if something is wrong when the needle barely moves. I figured i better do it now or it would never get done. I was able to get it re- calibrated by the manufacturer. Now it's actually useful. Glad I did it.

What's left to do?

Power Steering.  I bought an electric power steering unit and tried to fit it in under the hood below the brake booster, but there just wasn't enough room.  And fiddling with it was holding up the rest of the project. There is an under dash kit for the Miata that uses a Prius p/s unit.  It's around $1000, so I will probably make my own. We'll see how that goes.