Wednesday, October 12, 2016


If I did this again I think I would use a higher nominal voltage, maybe 144V.  I chose 96V because I already had a motor controller for 96V (quickly fried it) and a charger (just replaced).  However, 96V is sluggish to provide current and I often need to upshift for acceleration.  I certainly would want a higher nominal voltage if I did not have the 5-speed transmission.  4th gear only gets me to ~55mph floored, less when uphill.  DC motor speed is dictated by voltage and power is dictated by current, but when you have the full voltage applied to the motor you're not going to get any more current.  So you have to upshift to lower the motor speed.  96V does provide a nice safety feature though, the shock is less painful.

Friday, September 30, 2016

3 year aniversary

This post marks the end of my 3rd year driving electric.  4344 miles this year for a total of 13644 miles.  I estimate I have about 227 cycles on my battery with no issues.

Wednesday, September 14, 2016

new charger

Two weeks from my 3 year anniversary I decided to upgrade my charger.  For all this time I've been using the old heavy transformer rig from step 31.  It worked well enough but was very loud.  The 50' of romex wire I put in series with the output to drop a little voltage (to avoid melting plugs) heated the garage and required a box fan on it to prevent it from getting so hot it outgassed.  It was also a little awkward to plug in, requiring 4 or 5 connections to be made.  For the past year or longer these connections lived under the hood and looked like 2 extension cords.  The romex wire was introduced in the circuit after the plug on the side of the car melted. 

The new charger lives in the corner of the trunk and only requires an AC voltage connection, either 120VAC or 220VAC.  

From top to bottom is the rear battery, the motor controller, the DC/DC converter, and finally the new charger.  There are relays tucked around that are controlled by the BMS to turn the charger off at a set high voltage and to turn the motor controller off at a set low voltage.  The red/green/yellow dot is a status indicator.

Tuesday, February 16, 2016

BMS trouble

I've been getting communication faults with my Elithion BMS.  The BMS plays several roles.  It is responsible for turning off the charger to avoid over-charge, disconnecting the load to avoid over-discharge, as well as doing the same to avoid any over-temperature conditions.  The faults originate in one or more of the cell monitoring boards attached to each cell.  By observing their blinking pattern I believe at least 2 are faulty, both of them are nearest the opening of the hood which makes me wonder if the elements are too much for the PCB.  In the front all that protects them is conformal coating and the hood.  

Friday, February 5, 2016

old car "stuff"

Brake booster went out.  No power brakes and drawing excessive vacuum.  Ordered an aftermarket replacement and learned that car is a 2002tii and that the tii requires a differently sized booster (to make-way for some fuel injection parts) - the tii means that it was originally fuel injected.  It was carbureted long before I got it.  So to avoid redoing brake lines the correct booster had to be found.  This turned out to be a hard-to-find part.  

A shop in town send mine to Dallas to get it rebuilt.  A week later I received it back with news that it couldn't be rebuilt.  Finally a shop in California rebuilt it for a reasonable fee.  The car was out of service for about a month.