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
Wednesday, December 31, 2008
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.
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.
Cheers,
Tim
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.
Cheers,
Tim
Sunday, September 14, 2008
Just passed 6000 miles and fixed PakTrakr Issues
Two quick updates for the 914 EV since I've started working on the Civic-EV:
First, I just passed 6000 EV miles and the car is still going strong.
Second, the PakTrakr system has been acting up and reporting battery failures. At first, this really worried me that my battery pack wasn't doing well. Many first-time EV builders burn out their pack early.
Upon further inspection, the PakTrakr was reporting failures on batteries that were adjacent to the fusible links in the rear battery box and the front battery box. I tried an experiment by moving the PakTrakr battery wire from one side of the fusible link to the other. This should have theoretically caused no change because the fusible link should have no resistance. I was a bit amused to find that the "failing" battery jumped to the battery attached to the opposite side of the fusible link.
This experiment tells me that the fusible link has enough resistance to confuse the PakTrakr into thinking that a battery is failing. It shouldn't be too surprising since 200 amps going through 10 milli-ohms will cause 2 volts of drop, indicating a bad battery. The bolts on the fusible link metal had loosened up a bit and I suspect they had corroded as well, since the "fuse" is a different metal than the copper bar. I added Noalox anti-corrosion compound to the ends of the "fuse" metal and tightened down the fuse bolts to hopefully fix the problem.
Until something else major comes up, most of my efforts will be over at the Civic-EV blog.
Cheers, Tim
First, I just passed 6000 EV miles and the car is still going strong.
Second, the PakTrakr system has been acting up and reporting battery failures. At first, this really worried me that my battery pack wasn't doing well. Many first-time EV builders burn out their pack early.
Upon further inspection, the PakTrakr was reporting failures on batteries that were adjacent to the fusible links in the rear battery box and the front battery box. I tried an experiment by moving the PakTrakr battery wire from one side of the fusible link to the other. This should have theoretically caused no change because the fusible link should have no resistance. I was a bit amused to find that the "failing" battery jumped to the battery attached to the opposite side of the fusible link.
This experiment tells me that the fusible link has enough resistance to confuse the PakTrakr into thinking that a battery is failing. It shouldn't be too surprising since 200 amps going through 10 milli-ohms will cause 2 volts of drop, indicating a bad battery. The bolts on the fusible link metal had loosened up a bit and I suspect they had corroded as well, since the "fuse" is a different metal than the copper bar. I added Noalox anti-corrosion compound to the ends of the "fuse" metal and tightened down the fuse bolts to hopefully fix the problem.
Until something else major comes up, most of my efforts will be over at the Civic-EV blog.
Cheers, Tim
Monday, April 7, 2008
Switching Gears and Moving On
With almost 3000 miles of cheap, reliable operation, I think it's time to move on to something that will help more people do their own conversions. I really appreciated the high-quality parts and detailed instructions provided by Electro Automotive with their 914 kit. I would like to see the same thing done for a more modern, practical vehicle for much less cost.
You probably won't see much more activity on this blog in the upcoming months as I focus on developing an open-source EV kit for a '92-'95 Honda Civic. I invite you to come along for the ride over at civic-ev.blogspot.com
Thanks to everyone who has offered their support and knowledge during the 914 conversion. I hope this blog has helped many people convert their own 914s and save them time.
Cheers,
Tim
You probably won't see much more activity on this blog in the upcoming months as I focus on developing an open-source EV kit for a '92-'95 Honda Civic. I invite you to come along for the ride over at civic-ev.blogspot.com
Thanks to everyone who has offered their support and knowledge during the 914 conversion. I hope this blog has helped many people convert their own 914s and save them time.
Cheers,
Tim
Saturday, April 5, 2008
Going back to CAMP914
Yesterday was fun. I drove the electric 914 back out to Camp914 where I originally purchased the car and drove it away as a gasoline vehicle. Craig was happy to see me and took several pictures. Since the round-trip drive was 44 miles and included several long hills, I charged up for an hour out at camp just to give myself a bit of breathing room. Overall, the car handled the freeway and hills well.
Here's the 914EV charging up at Camp914.
Camp 914 is a fun place with many 914s as well as other Porsches and classic cars.
On a slightly more frustrating note, the LED flasher still isn't behaving the way I like it to, so I took it apart again to see if I could adjust the resistor values. I tested the unit by hooking it up to a 12V SLA battery and applying varying resistances to the output terminal to simulate different light-bulb loads. In my haste, I tried to unsolder a resistor while the battery was still attached and I fried the circuitry (oops!). I guess experience varies proportionately with equipment ruined. I ordered another flasher and put the original one back in the car along with two incandescent bulbs to give it enough load to operate.
I've mentioned before that I'm working on an open-source EV kit. Today I drove out to the U-Pull-It wrecking center and took a bunch of pictures of '92-'95 Honda Civics to see how I could design battery racks for them. The 914ev blog might be winding down as I put more time and energy into the open-source project with its own blog. I'll keep y'all posted as this gets going.
Cheers,
Tim
Here's the 914EV charging up at Camp914.
Camp 914 is a fun place with many 914s as well as other Porsches and classic cars.
On a slightly more frustrating note, the LED flasher still isn't behaving the way I like it to, so I took it apart again to see if I could adjust the resistor values. I tested the unit by hooking it up to a 12V SLA battery and applying varying resistances to the output terminal to simulate different light-bulb loads. In my haste, I tried to unsolder a resistor while the battery was still attached and I fried the circuitry (oops!). I guess experience varies proportionately with equipment ruined. I ordered another flasher and put the original one back in the car along with two incandescent bulbs to give it enough load to operate.
I've mentioned before that I'm working on an open-source EV kit. Today I drove out to the U-Pull-It wrecking center and took a bunch of pictures of '92-'95 Honda Civics to see how I could design battery racks for them. The 914ev blog might be winding down as I put more time and energy into the open-source project with its own blog. I'll keep y'all posted as this gets going.
Cheers,
Tim
Saturday, March 29, 2008
Going to the Portland Better Living Show
Yesterday was a long day. I spent over seven hours on my feet at the Portland Better Living Show displaying the 914. My throat was hoarse at the end of the day from answering the same questions many times. Overall, people were very interested and I'm hoping a few will show up at the next OEVA meeting.
Many thanks to Gary Graunke (who set this whole thing up), Ken (forgot his last name) and Joe Williams (on the left) for hanging out with me during the nine hour show. Joe and Ken will take care of the booth today and I'll finish up the last six hours tomorrow.
On a side note, I purchased a DVD from Bob Bath regarding his CivicWithACord project. He's documented much of the work needed to get a fifth generation ('92-'95) Civic converted to electric. This is one of the prime candidates for the open-source vehicle conversion kit I'd like to work on, so there's lots of information to leverage.
Many thanks to Gary Graunke (who set this whole thing up), Ken (forgot his last name) and Joe Williams (on the left) for hanging out with me during the nine hour show. Joe and Ken will take care of the booth today and I'll finish up the last six hours tomorrow.
On a side note, I purchased a DVD from Bob Bath regarding his CivicWithACord project. He's documented much of the work needed to get a fifth generation ('92-'95) Civic converted to electric. This is one of the prime candidates for the open-source vehicle conversion kit I'd like to work on, so there's lots of information to leverage.
Subscribe to:
Posts (Atom)
