Millenium Falcon Update

A short note to update you on a couple of Millennium Falcon things, dog happens and the scary 12 V battery message.

Dog Mishap

Rocky narrates.

As you can see, Millennium Falcon has plenty of room for a greyhound or two. I’ve been riding back here as I can muscle up pretty easily. Missy is riding row two as she has trouble making the back in the carport. Miss this leap and you can tear your hip capsule, a serious, possibly life-ending injury. It happens as we get older (after 10).

Anyway, the staff was opening the driver door to retrieve something like the USB car tunes button. I tried to board crawling under the wheel and over the console and got a trotter in the open phone pooka. Pooka can be Celtic for spirits of one sort or another (but not the potable kind). Or it can be submarine/Navy for a small storage space. The phone shelf is an example of the latter.

The antenna assembly snaps in with a plastic flange supporting it. A thin plastic flange. After all, normal load is well less than 1 Kg. But a dog paw fits through the roll-top easily. And the sliding top exposes the phone shelf a bit. Enough for a big 40 Kilo beast to trod on it. Crunch. USB unplugged. All passenger USB out. WiFi out. Phone charging out. Oh, and it is a $600 part! The working parts are fine. Checkered Flag VW reconnected the WiFi and USB and stuffed some cardboard under to raise the shelf to usable. Just the stupid mounting flange failed.

Really, don’t VW engineers have dogs? Don’t they take their dogs about in the test vehicles? Don’t they note and fix the rough bits? I suspect VW engineers have basket-riding bag rats, not manly dogs like me that ride loose.

Stupid Message

The Falcon was in space dock for a few days without travel as tourists were crawling over the beach and church was ditched to sleep-in. So the Falcon’s 12 V battery ran down enough to need a charge. I (Dave writes) hop in to go grocery shopping to top up on summer fruit and pantry supplies. I put Falcon in start and a scary message about HV electrical trouble greets me. I watch the car complete POST and come to READY with full power available. WTF, VW?

I drive down to Wegmans for a shop, about 20 minutes underway, park, and go in. I return after shopping to drive to a second supermarket to complete my list. (Wegmans is wonderful but they never have Rao’s Sausage and Mushroom sauce. That’s the best of the lot, meaty with a minimum of meat and lots of button mushroom slices.)

Falcon starts without messages. The HV trouble annunciator is cleared as a short drive remedied whatever was the matter. Apparently, Millennium Falcon needs regular exercise.

More about EV Batteries

There are at least two, the HV battery that runs almost everything and a 12 V aux battery that runs the locks, HMI displays and processors, lights, and stuff that you need to get in the car and start up the HV system and the 12 V inverter that powers all the accessories underway. Once the HV power electronics are going, the HV to 12 V inverter charges the 12 V aux battery that keeps the car alert between trips.

The 12 V aux battery is a deep cycle marine battery, usually small frame size, that normally powers sailing vessel amenities when the engines are secured. These are very similar to trolling motor batteries used by bass fishermen to maneuver around a fishing hole. They are made to supply moderate current for a long time and to be discharged fully and recharged.

These batteries have a short service life because the charge/discharge cycles cause the plate structure to change and plate bridging can occur. They have been a reliability sore spot for most EV brands. Even Tesla.

Most famously, a 12 V aux battery made James May walk when he returned to his Tesla Model S as lock-down was ending. James May, being a YouTube film maker, made a little film showing with James May understated irony the pains needed to uncover the Model S aux battery for jumping or replacement.

Tesla buried the battery out of sight under the bonnet trim. And to remove one plastic trim bit required pulling a T-handle cord that could be reached only by removing a front wheel. Oh, there were two lanyards to pull, one in each wheel well. Who would think you should need to lift the vehicle to replace a regular 12 V battery? Tesla, obviously.

So duly embarrassed, Tesla designed a replacement Lithium iron phosphate replacement battery in a nice little aluminum box that should last the life of the vehicle. More likely, the life of several batteries as the cells chosen have a much longer lifetime that the traction battery cells.

Tesla is unusual in the industry in that it has a vigorous program of continuous improvement. As Tesla discovers friction in assembly or in service, Tesla revises its vehicles to remove the source of difficulty. The replacement lithium ion 12 volt aux battery is a classic example. Many of these planned improvements significantly reduce build cost, build time, or field service costs. Today’s Model S and Model 3 are very different under the skin than the originals.