Sunday, December 20, 2009

Update to Azure Dynamics DMOC Information

I've been receiving several requests this past year for the FTP site that contains the information on the Azure Dynamic DMOC445 controller.

I just received word from Azure Dynamics that they posted all this relevant information online here:

Have a great Holiday Season!


Sunday, February 8, 2009

Saying Goodbye to my 2007 Dream Project

I contacted someone who expressed interest in purchasing the 914 a few months ago and that contact came through for me.

Here's my parting shot with Dan, the new 914 EV owner. Dan has worked with a Bradley GT EV before, so he knows the ropes. I'm sad to see the car go, but I've got the Civic-EV and it does very well. I'm still active on the 914ev Google Group answering questions, so I'm not completely disconnected.

Farewell 914EV... I learned more than I ever expected.

Best wishes to all doing EV conversions.


Tuesday, February 3, 2009

Time to sell the 914

It's time to sell the electric 914. It's been a fun road, but I have three cars now (as a single guy) and only a 1-car garage in the middle of the city. The car has been good to me and made the electric Civic project go so much faster. I've learned much and shared many experiences with other people converting 914s. The car has been a major hit at EV shows and with friends.

Having just finished the Civic-EV, I realize that I need a car that seats more than just two and holds more than just a small bag in the trunk.

You can see more information on the car at the EVAlbum entry:

Please contact me at the e-mail listed at the link above in case you're interested.

Many best wishes to everyone,

Bypassing theCharger

Since my battery voltage never gets above the cutoff point for the Zivan charger bulk phase, I made a special charging cord with a timer built into it. If I leave the Zivan in low-current mode, I only pull 12 amps, which is less than the 15 amp rating of the timer.

Since I know how many amp-hours I pull from the batteries during my commute, I can generally pick a good timer setting to get the batteries close to full without "boiling" them too much. I think this will work out fine until I replace the batteries or sell the car.

Not ironically, I've been having problems with the charger on the Civic-EV not getting out of bulk-charge mode too, so I built a second timer-cord for that car too.

Wednesday, December 31, 2008

Battery Degradation

Ugh. I think my battery pack is slowly dying after 8600 miles and 1.5 years.

My Zivan charger alarm has gone off for the past week and I finally looked into it. Apparently the alarm is indicating a timeout that the charge cycle is taking too long for the capacity of batteries that I have. If I charge overnight, I wake up in 40 degree weather and the pack is very warm, around 80 degrees with vigorous "boiling."

After doing some analysis yesterday, it looks like the batteries are not getting past the initial "bulk" charging phase. The charge curve in my Zivan dumps maximum current onto the batteries until the voltage reaches 171.6 volts and then holds it there until the current dies down before putting a final equalizing charge on it. I found that the whole pack during bulk charge never gets above 170 volts, even after several hours of charging. It seems like the plates are sulfated enough to reduce their capacity and reduce the "gassing" voltage significantly.

After contacting Zivan tech support, they said that lead-acid batteries typically get 400 deep cycles or 800 half-cycles at best. If my average trip is 20 miles between charges and I have 8600 miles on the car, that means about 430 half-cycles. This seems a bit low to me, but since this is my first EV, perhaps I treated the batteries poorly the first time around.

With the significant gassing happening, the front luggage compartment also has some acid rust under the front box (similiar to the "hell hole" in the original 914 engine compartment). I'm a bit disappointed, but it's been a good run.

On a side note, I also blew a fuse yesterday after cleaning out the rear trunk because I pushed two of the fast-on connectors together under one of the tail light assemblies. If your fast-on connectors under the tail lights don't have heat-shrink tubing around them to prevent shorts, I hightly recommend that you add it. It only takes 15 minutes and will save a lot of headaches.

Happy New Year

Friday, October 17, 2008

Fixing the Aux Battery Killer

I took the time today to research the 914 wiring diagrams and find the annoying connection that leaves my tail light on after I turn off the ignition switch.

If you remove the front dashboard cover and look under the steering column, you should see two connectors. Remove the right one as shown above.

On the rear of the connector should be three wires colored grey, grey/red and grey/black. Snip the grey one and seal BOTH ends with heat-shrink tubing or end-wire crimp. After cutting this wire, you will no longer have the feature that turns on your tail lights when you leave the turn signal lever activated. It's important to protect both ends because one is tied directly to the 12V battery through a fuse and the other gets 12V when you turn the tail lights on. You don't want either of these touching any part of the grounded chassis.

I really hope I'll never kill my 12V battery again by leaving on the turn signal. Other critical functions (like the emergency flashers) still work fine.

Okay, back to driving and finishing up the open-source Civic project. Best wishes to all.

Tuesday, October 14, 2008

Quirky Porsche Features Killed my 12V Battery

The Porsche 914 has a bunch of "distinctive" features that make it different from many other cars. One is the hand-brake being on the left side of the driver's seat (enabling a "racing start"). Another quirk is that if you leave the turn signal on after removing the ignition key, your tail light on that side stays on. This has the unfortunate side effect of draining your 12V battery.

I've left my turn signal on before, but the combination of the LED tail-lights and the deep-cycle accessory battery kept the car alive. Well, today my 12V battery died. I was able to "jump-start" the car by using my 12V fan-power transformer to activate the DC-DC converter relay. This enabled the DLS-45 DC-DC converter to quickly charge the 12V battery off the main pack. Unfortunately, the 12V battery had drooped down to 3.2 volts which is a very bad sign.

I ran out this evening and purchased a 12V AGM battery to replace it. The non-spill properties of this new battery will also prevent acid splash from hurting the front of the trunk.

For the future, I'm going to find that dang wire (it's in the electrical diagram) that enables the "leave light on when turn signal activated" feature and cut it. I'm also thinking about drilling a
small hole in the side of the DC-DC converter relay so I can easily "jump-start" my 12V battery by simply inserting a non-conductive pin to force the relay arm closed.

The adventures just keep coming. Best wishes to all in the process of their EV conversions.