Wash and Wear

Wipers and Washers

For a bit of a distraction this weekend, I dove into the windscreen wipers and washers.  The wipers were operational, but very slow.  The washer was an unknown situation.

First was the washer motor.  It is shown below behind the washer bottle.  The motor was pulling current but would not spin.   It was simple to disassemble, just a few tabs to bend back.  It didn't look too bad inside for a 40 year electric motor that has been exposed to moisture its whole life.  The motor was frozen but a little persuasion and it spun free.  A few drops of lithium grease on the shaft and it was humming away.  The pump is in decent shape and just needed a little cleanup of the o-ring.

The washer bottle was another story.  It had a 4" crack on the back side where it slides into the mounting bracket.  Well, a little fiber-glass patch work and it was water tight and probably stronger than the original plastic.  Reasssembled the system system and water sprayed out of both nozzles.  Two issues still:

• The spray jets are positioned right under the wiper arms and thus very little water gets to the windscreen unless the wipers are going.    
• There is no switch to activate the washers.  The wire is behind the dash, but it is not clear where the switch is or was.  Some Minis have the washer switch on the turn-indicator stalk, but Jane's stalk is already full with high-beams and the horn.  A new switch will have to be added to the dash

Black Washer Motor behind yellowish washer reservoir. 

The Wiper motor shown here was mostly just gummed up.  After opening it, cleaning out the 40 year old grease (it wasn't very greasy anymore) and trying to clean-off as much exterior grime as possible, it now spins great with two speeds and automatic parking.  The park switch was a bit sensitive to how the connectors were attached, but after a small adjustment of the inner switch connection, the parking function works as expected.  There is a plunger that is pushed from the motor shaft that separates a contact in park-switch when the motor is in the parked position, stopping its rotation.  One interesting observation about the wiper motor.  The cover holds the permanent magnets and is not marked.  It has two possible orientations, 180 degrees apart.  In one orientation, the motor would spin the drive gear counter-clockwise.  In the other, clockwise (the proper direction).  Of course, it took two tries to figure this out.

Battery Monitoring

The battery monitor has advanced quite a bit.  Shown here is the four CellLog 8M based monitor.  The CellLogs are mounted on a board from ElectricPorsche.ca.  Robin at Electric Porsche has designed this board which was a perfect fit for Jane's needs.  It now monitors all 26 cells and activates a loud piezo buzzer if any of the cells are out of range.  I currently have them set at 2.50V - 3.55V as the normal range.  The looping wiring on the right side is setup to assure that if a CellLog fails or a wire comes loose, the alarm will sound.  The CellLogs keep the 4 relays closed when on and not-alarming.  If a CellLog goes off or alarms, it ceases to maintain the closed relay and the buzzer is sounded.    This system mounted in the boot, on the boot lid, so it folds down quite nicely for easy viewing.  Also, I moved the 600A contactor back to the boot today so that it would not be exposed to the elements under the hood.  Was able to use the electric fuel-pumps power to activate the contactor when the 12V system is turned on with the ignition key.  Just one of the many clean-up things that needed to be taken care of.

Charging update:  With the CellLogs operating now, I have turned down the charger to an 86V terminating voltage, which is 3.3V per cell.  The charger is designed to switch to constant voltage at that point until the current drops to about 1 amp.  This is not the fastest way to charge.  When the charger was set to 91V, a few of the cells would exceed the 3.55V alarm voltage before the pack reach 91V (26 x 3.5V).  Wanting to be conservative, I opted for a slower charge at a lower constant voltage, which should be easier on the cells.  After a couple of charge cycles with this new setup, all of the cells are staying within 30 mV of each other.  LiFePO4 batteries have very steep voltage curves when they near the end of the charge cycle, so as the few slightly fuller cells got near the end of the charge, they would shoot up the voltage curve triggering the out-of-range alarm while the rest were still taking in the last few amp-hours.