Corbin's Treehouse - Corbin Dunn, Santa Cruz, CA
Plug Bug

Archive for the 'Electric Bug' Category

Plug Bug: New front brake pads

I wear out brake pads faster than normal since I don’t have regenerative breaking or a normal “ICE” engine to slow me down. I replaced my first set of pads really quickly, but the second set seemed to be lasting a lot longer. I would keep an eye on them and see how they were doing every now and again, and a month or so ago they looked good. But today, the bug’s brakes were screaming (a crunchy metal on metal sound), and I knew something was up. The bug has also been pulling slightly to the right when braking, so I wasn’t too surprised.

The front right disc brakes looked like this:


The cheap EMPI disc brake calipers aren’t as smooth on one side, and the wear was twice as much on one pad as the other half! Of course, when I checked them, the pad with good wear was on the outside, so it was the one I could see and verified looked okay.

Doh! I replaced them tonight (I had a set on hand just in case!). The ‘ol Electric Bug has 32,170 pure EV miles.


I got about 20k miles out of those pads; I could have gotten at least 2-3k more if the wear was even.

“No Dino” stickers

Got em! On my J1772 inlet “gas tank” cover.



No Fossil Fuels Sticker

I finally cleaned up my “no fossil fuels” sticker for EVs! I just ordered a few stickers (8) from StickerYou — — the place has a decent website, but they have a terrible security flaw of emailing you your signup password back in plain text! That is just a huge security “no no” and I can’t believe companies do this. The order page also failed for me like 5 times; I had to finally use paypal to get it to work (which also took three tries!). We’ll see what the quality of the stickers looks like; unfortunately, they only accepted PNG, and not PSD files.

It was difficult to find a sticker printing service; I wanted stickers that were vinyl and could last outside. This eliminated a few sources. Check out: for a list of places. PsPrint could have done it, but to do a custom circle shape cut would have been at least a few hundred minimum. VistaPrint looked good and had nice PSD Layout files…but couldn’t do vinyl in the pure circle shape (they could do an oval shape). I still might try them (non-vinyl) if the ones I ordered from sticker you come out terrible. All others seemed to have terrible quality based on the reviews.

PNG below. Feel free to download it. I can email you the high quality 3″x3″ PSD file (with trim marks, etc). The outer red edge is meant to be used for cropping the cut circle, which is why it isn’t a perfect circle.

Jurrasic Park No gas logo 3x3 cropped2.png

Bug Down again.. and don’t use Fortes Brothers Towing in Cupertino!

First off, don’t use Fortes Brothers Towing in Cupertino! They are terrible, and don’t know what they are doing. AAA called them to tow my bug home from work (in Cupertino), and the guy had it almost setup and just said my car was too low and they don’t do lowered cars! I’ve had the car towed 3 or 4 times before; never have I had any trouble at all. Worst off, the idiot driver drove away with my laptop and at first they refused to acknowledge they had it! AAA said all I could do was file a police report. But, after I called the company, they admitted they did have it and would give it back. geez. I ordered a flat bed truck from AAA, but unfortunately the same tow company (Fortes Brothers) canceled the tow without telling me! I sat around waiting for a tow that never came.

But anyways, my car was having a “frame leak”, which means the high voltage had potential when compared to the chassis of the car. This should only be used for the 12v ground, as the high voltage battery pack needs to be completely isolated for safety. I realized something was wrong last week because my car was giving “GFCI faults” at the Chargepoint stations. However, it seemed to still charge okay on a 240V dryer plug at home, so I drove it to work and charged it there on one of those plugs. But then it wouldn’t start; my Elithion BMS was going crazy giving faults, and the controller didn’t want to click on. I realized it was a frame leak, and traced it to my Belktronix DC-DC converter. While waiting for the tow truck driver I popped it out (thanks to Shane for helping me at work and giving me a ride home!), and stuck it in the mail the next day.

Good Times!

A local weekly newspaper in Santa Cruz, The Good Times, did an awesome article on my VW bug and myself.

Check it out here: The Plug Bug and Corbin Dunn.


Broken EVSE (charging station)

I was charging my car last week at home and started to smell some burning plastic. It was coming from my EVSE (the “charging station” which is a gloried relay with a few electronic smarts).

Popping it open revealed that my plug attachment was shorting out a bit:


I now realize what happened; I had did the stupidest thing last summer and drove away with my car plugged in at home. I had shut the front trunk, and failed to unplug the car in some bit of absent mindedness. The cord got really taught as I was backing up and made a noise that alerted me to stop. It broke the J1772 inlet on my car, which I glued back together.I took a look at the EVSE and it seemed okay, but now I realized I had pulled the power cords out just enough to allow them to still work, but have high resistance.

I just hardwired them directly to the input wires with some electrical twisties.

EV Page of Shame: Post 1

Welcome to the EV Page of Shame!

The first victim.

This little lovely neighborhood EV was parked in the decided EV spots in the downtown Santa Cruz parking garage. But it was not charging! Shame on you. All the other spots were taken, and people could not charge because you took this spot! Please be courteous. (I would have left a note but I had no paper).


Plug Bug: Bad cell

Well…lost a good post on my bad cell.


Long story short: one cell has been sagging really badly, so I replaced it. About 20,500 miles.

The bad cell had high resistance, and was swelling at the top slightly. The cells were never really abused. Never overcharged (although, at first I was charging them to 4.0v, per the spec that came with them. I now charge to 3.7 or so).


Plug Bug: Transmission replaced

Some updates on the electric bug. Back on Thanksgiving I was on a slight hill pointed downwards (at Nathan’s house). I put the car in reverse, but missed the gear and stepped no throttle. The car didn’t move, but the motor sped up quite a bit, however, I couldn’t hear it. I slammed it hard into reverse, without using the clutch, and the car made a big “thunk” noise as it went into gear really hard. Ever since that happened, the car would not stay in second gear, and kept popping out quite frequently. It appears I damaged the tranny.

So, I got a new one from Bugformance. Not cheap, as it was about $1000 out the door with a few seals and new gear oil (and that is excluding the $300 core deposit). I could have probably got one online for cheaper…but then I would have had to wait a few weeks without driving the car (or driving it in a rather unsafe manner).

I always have to re-remembrer how to do things, and it took me a while to get the old tranny out:


Then stick the new one on. It went in pretty easily. The new tranny is rebuilt with the gear ratios (1st-4th): 3.8, 2.06, 1.32, 0.89. The casing was quite a bit beat up compared to mine…but I didn’t really have a choice.


So far, so good. This all happened a short bit before 20,000 (electric) miles:


BMS Display part 4 – graph

I updated my BMS display software to actually respond to the buttons I have. Now I have another screen of data, graphing each cell. The graph goes from 2.0v at the bottom to 4.0v at the top and shows the min and max cell numbers (and the voltage). My cell #38 is dying. It is starting to trip my BMS when my pack is only 50% charged. Actually, it shouldn’t be tripping the BMS because it does sag to a pretty low voltage, but it always comes back up to > 3.00v when resting (i.e.: under no load).

The updated display:


The code is also on github for my user corbinstreehouse.

Here is a video of it in action. Sorry, it is shaky, but that is because I’m holding my phone in one hand while driving a small mountain road.

My bad cell can be seen in this screen shot:

Screen Shot 2012-11-25 at 8.44.36 PM.png
It is sagging to 2.57v under load! I draw the line in red when it is less than 2.8v, and orange when it is less than 3.0v (and green when under normal voltage).

(c) 2008-2012 Corbin Dunn

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