Friday, May 10, 2019

Rearranging the Deck Chairs

The AutoBlockAmp device that drove the ammeter and (intermittently) the fuel gauge on the evTD dashboard packed it in last Winter. I had been a beta tester for the developers at Rechargecar and I must have done a pretty lame job because the product never did get quite right even though they were selling and shipping it. Rechargecar is now out of business so a replacement is not in the cards. 

Happily, I had earlier found and installed a combination ammeter/voltmeter/state of charge display device to replace the JLD404. It also functionally replaced the ammeter and fuel gauge that were driven by the AutoBlockAmp, so when that failed I was in no hurry to deal with it. We've had a solid week of rain and I took that opportunity to remove the failed gauges and tidy up the basket of snakes behind the dash.


In the rush to completion in 2012, I had just loaded in the dashboard components and put a zip tie here and there to keep the stray wires out of sight. Not a pretty sight and not very maintainable, so this seemed like a good time to make order out of chaos.

Removing excess wire length and encasing everything in split loom makes a huge difference. No one will see it, but it will give me some peace of mind knowing that things are secure and not flopping around back there. I replaced the fuel gauge with a clock from Speedhut with the same face design as the other gauges, then promoted the combo volt/amp/SOC display from its separate bracket below the dash to cover the hole where I removed the old ammeter. It stands a bit above the dash surface, but puts that info in the line of sight. It's a departure from the vintage analog look I started with, but more useful.















Tuesday, March 12, 2019

Not Precisely an EV, but ...

Not precisely an EV, but the first commercially available hybrid vehicle in the US. This is the car that started me down the EV road, and saved my wife's life in 2009. 



I traded my beloved Miata on a Honda Insight very similar to this one in the early 2000's and enjoyed getting over 50 mpg without even trying. It's rather a different approach from that taken by Toyota with the Prius: a 1 litre 3 cylinder 67hp gas motor drives the car with a 13hp  electric "assist" motor that provides up to 36 lb-ft of torque on demand. The electric motor is powered by a 144 volt NiMH IMA (Integrated Motor Assist - Honda's name for its hybrid technology) battery pack that is recharged through regenerative braking. The key to its high mpg rating is its tiny size, very low 0.25 drag coefficient, and lightweight aluminum structure and body.


That aluminum structure might seem a bit fragile, but it's quite strong and here's where the wife comes in: she survived a head-on collision with a spinning SUV with her injuries mostly caused by the air bag. The crush zone crushed as designed with the passenger compartment unscathed. Even the doors and hatch opened and closed as if nothing had happened. The insurance company totaled the car, and I have missed it ever since.

So why buy a twenty year old replacement now? Our 2016 Nissan Leaf is nearing the end of its lease term and Beth and I have become adherents of Dave Ramsey's "Total Money Makeover" principals which rule out leasing or financing depreciating assets like cars. While I want my Tesla Model 3 in the worst way I don't have a savings account that will let me pay cash for one even though the $35,000 entry model is now available. By the time I have cash available, low mileage used Model 3's should be on the market with their initial depreciation behind them. Can't wait!


But for now, this 2000 Honda Insight turned up on Craigslist over the weekend with only 57,400 miles on it. A quick test drive told me everything was working on this car, pretty much like a younger low mileage example, and it drove exactly as I remembered my original. The IMA battery had been replaced in 2015 and seemed to be working properly. It was a non-smoking car and while pretty dirty, it cleaned up nicely. Except ...


It was a fleet vehicle for the City of Austin Parks and Recreation department and says so right on the doors. Someone tried to remove the graphics and gave up before the job was done. I expect a little patina on a car that has spent its twenty years exposed to the Texas sun, but I need to get rid of the civic advertising. WD40? Goo Gone? Compound and a buffer? Eraser wheel? Google presents so many choices ... just don't want to spring for a respray.

The net of all this is that the Insight is a car Beth is comfortable driving (she wouldn't consider the Porsche or the MG) for those days when her Prius is getting serviced or I need it to transport the grandchildren. It was a low cash outlay for a bridge from our Leaf into the Model 3 of my dreams.


Footnote:

While my new Insight is a low mile, low cost find, apparently there is something of a cult following for these cars among hypermilers and other eccentrics which has led to some outrageous prices and bidding wars on these things. The seller raised the price on mine after we arranged the test drive. He honored the original price he had posted since I was local with cash in hand. He decided to raise the price after he got a call from a guy in Indianapolis who wanted to fly down and drive home and said he'd pay up to $5000 if he'd hold the car for him. Happily no deal on that one.

Will I be converting the Insight to a full EV someday? Maybe. It's been done, here's a beautiful conversion by Mark Bishop I saw at EVCCON (free registration required). I see examples of Insights with over 200,000 miles on them still going strong, so it may be a while.

Stay tuned ...

Sunday, October 28, 2018

If It Ain't Broke ... Part Deux

Since the new Volt/Amp meter was such a hit in the PorschEV, I ordered another one for the evTD. I failed to point out in my earlier post that this device, unlike some other Chinese wizardry, comes with documentation that is actually useful and even in color!

It will replace the trusty JLD404 that has served so well for the last six years. Like the EVIC, it became invisible in sunlight. The JLD404 has the logic contained in the display, so it needs to be powered on full time to retain the cumulative amp hour data. 

That led to several "bricking" incidents where the 12 volt auxiliary battery went flat. I designed a module to keep the 12 volt battery charged from the main pack whenever it gets low. The display of the new Volt/Amp meter will be turned off when not in use, so it will add less parasitic load.

This was a fairly straight forward like for like replacement, so the 1000 amp JLD404 shunt was swapped out for the 500 amp shunt/logic unit.







Similarly, the JLD404 mounted below the dash was replaced by the new unit.

Where the JLD404 displayed only one value at a time and had to be toggled from amp hours to run time to amps to volts, the new meter shows volts, amps, and run time simultaneously with the battery capacity gauge representing amp hours. Amp hour data can be seen on a detail view that also allows for configuration.












Postscript:

Discovered that the inverse display really is visible in direct sun! That's good news since the top is rarely up on the evTD ... too much fun open air motoring.



If It Ain't Broke ...

The patron saint of aging do-it-yourselfers, Red Green, said it best. After a summer with no break downs or other excitement, I was feeling the itch to make some "improvements". After all, projects like EV conversions are never really finished, they're just waiting for the next opportunity for skinned knuckles and sore backs. The internet presents all kinds of temptation, and I'm a sucker for amazing Chinese technology.


I found this little gem on Amazon and it seemed too good to pass up: a voltmeter/ammeter with simple amp hour counting to drive a battery gauge for a remarkable price and available in the US with free delivery for Prime customers.

The illustration shows a USB connection from the shunt/logic unit to the display, but it also has a built-in wireless link. The font is a nice size and can be reversed (black on white) for better visibility. While it caps at 300 amps it has a 500 amp shunt. I have never seen over 300 battery amps on either the MG or Porsche, so at 400 volts it should be just right.


You may recall that the PorschEV dashboard was built around an EVIC display for most of the system monitoring. As it turns out, there were several factors that have made it less than optimal as I lived with it for the last three years. First, it is very difficult to see in any kind of sunlight. The only time it's really visible is during night driving. Second, since I revamped the cooling system, the temperature read-outs have been largely irrelevant. If I need to check the temps, I can access the wireless GEVCU data from my iPhone. Third, while it accurately displayed the pack voltage, the amp hours and battery capacity display never worked correctly and for reasons I fully understand and accept, were not going to get fixed. Finally, after reconfiguring the GEVCU for full power, I learned that the Siemens motor had plenty of torque to essentially go direct drive. I wired in a switch for electronic reverse and simply leave the transaxle in fourth gear. That makes the rev counter display uninteresting. The net result is that the EVIC display was not adding much value to the driving experience.


The original dash panel was still gathering dust under my workbench, so a little fun with a hole saw made it a nice place to reconfigure the driving info center.








Black paint makes the base disappear. The speedometer was mounted in the center with the Volt/Amp meter on the right and the air conditioning control to the left. You may recall that I originally placed the AC controller on a windshield suction mount because there was no room on the dash. Now it's nicely integrated and in the line of sight.



You may also recall that I cobbled together a charging display for the rear of the car so I could keep tabs on charging progress. That required an extra contactor, a shunt, a couple of relays, and a box to mount the display and hide the spaghetti wiring. Oh, and it burned out pretty regularly. Not terribly expensive, but not the kind of reliability you'd want for a plug and play function. 

Since the shunt/logic unit supports multiple displays, I replaced all of that paraphernalia with a single piece. Wireless is very cool!








Neglect is the sincerest form of ...

Neglect is the sincerest form of saying "Everything's going great!" Sorry I haven't posted in such a long time, but there's not much interesting about just driving and enjoying the family fleet of EVs.

The Autumn season brings a couple of favorite car shows to display the conversions. First up was the Texas All British Car Day show in Round Rock. While the evTD is a mongrel: German chassis, Chinese Batteries, with US content being a body from South Dakota, motor from Illinois, and controller from Florida, most of the chrome is genuine British MG parts. It does personify the essence of British motoring so the show organizers let me in, but relegated it to the "Special Interest" class where we were surrounded by MGB's with monster V8 engines. Beautiful workmanship all around and I must say we were right at home and attracted a nice crowd to the outskirts of the show.


 A week later was the IBM Car Show held to promote the Employee Charitable Contributions drive. It was a gorgeous day with most of the cars owned by other retirees.



The spectators were largely current IBM employees, mostly of a technical sort, so plenty of deep dive discussions into the componentry and design specs of the PorschEV. Lots of fun!


Tuesday, February 20, 2018

Mechanical Stuff

Has it actually been over six months since my last post? Time flies when you're having fun. Not really a lot to talk about, just incidental nuisances with things unrelated to the electric nature of these cars plus a few minor electrical glitches. For instance:

The driver's side door handle on the Porsche broke. I mean broke as in "thirty year old metal fatigue". Replacements are available but a bit pricey. The good news is that it can be installed without disassembling the whole inner door panel. Unfortunately, no photos.




On the MG, the steering box was the only moving part that wasn't replaced when we did the conversion and it's become pretty obvious that it should have been. What started as a vague off center feeling in the steering became a scary lack of response to steering inputs. A new steering box was the order of the day and fixed that situation right away. It's nice to have the car go where you point it.

After I replaced the wonky steering box on the MG I was enjoying a test drive when I smelled a hot plastic electrical smell. Back in the garage I noticed that the Battery Management System had lost touch with a block of cells and after major disassembly found a burnt cell board and a main board that had oozed a bunch of silicone all over its housing. I know - Jack Rickard told me so - but after six years in service, I finally removed the BMS and bottom balanced the GBS pack.



Burnt Terminal
Bleed charge off with PowerLab 8
Final trim with home made resistor



After six years, the GBS pack is still at full capacity and reasonably well balanced. So now, BMS free one day at a time.

With all that done, it was time to tackle a two year old problem with a broken transaxle mount. This is the second time that the forward mount has broken, this time not as a result of drag racing, just every day use. The car remained drivable but made an annoying "Bump-Bump" noise as the rear of the motor bounced off of the rear cover whenever torque was applied. Since the mount was broken and could be removed in two pieces, we were able to do the replacement with the motor and transaxle in place.

The new mount has no rubber buffer and is a solid piece welded up from quarter inch steel. It's sold for "off-road use only". I suspect it would be pretty harsh with the old VW boxer motor but smooth as silk with an electric, and with any luck significantly more durable. It raised the rear of the motor enough to cause interference with the tachometer sensor on the tail shaft of the motor, so I had traded "Bump-Bump" for "Screech-Scratch". Simple fix for that is cutting a clearance notch in the rear valence.


The MG now has the drivability issues sorted out just in time for Spring weather outings.

Saturday, July 29, 2017

CHILL!!!

Man, has it been hot here in Austin. With highs approaching 110F, temperatures in the garage are in the low 100's during the day, so working on the Porsche has been a sweaty endeavor. We installed the Benling Air Conditioning compressor in the car early in the build process, but there were some things that needed to get done before it could be put into service. The car's cooling system, radiator and fans, needed to be uprated and I had to figure out how to mount and wire the controller. So here we are after almost two years on the road, finally ready to put a freon charge in the compressor and enjoy some cooler motoring.


New compressor in place.
Sadly, after doing the freon charge the compressor just sat there, inert and stupid. Can't know for certain, but I suspect that it was a victim of a known issue that I failed to account for in the initial installation. That makes me inert and stupid. Here's Jack Rickard's explanation in the first twenty minutes or so of this video from August 13, 2010. In short, the compressor's input capacitors work their little hearts out trying to run the car's motor! Except mine never blew a fuse, just burned out the inverter that's built into the compressor after two years of unprotected exposure to the traction pack. Expensive lesson learned.


New A/C contactor hiding under the two red cable boots


Thanks to Jack Rickard and Bill Bayer for shipping my replacement so quickly! This time I may have erred on the side of excess caution, but I completely redesigned the A/C circuit to include a spare contactor I had in a box of stuff and a 400 volt 100 amp diode to prevent any outbound current from the A/C unit. Since the compressor and charger share an input line from the battery pack, both are protected. 




The new compressor also came with the newer design controller which is not quite as ugly as the original. One of the delay factors in bringing the A/C online was my attempt (without success) to use the original dashboard controls to manage the compressor. I hate to chop holes in the dash or otherwise bastardize its classic look, so a suction windshield mount for an iPhone did the trick. I also added an on/off switch to the console in an existing hole to power the compressor contactor and controller simultaneously, keeping them both out of harm's way when not in use.

Speaking of harm's way, I had to crawl deep under the dash to pass the wiring through the firewall. I had fished some of the earlier wiring for the charger and dash gauges through without doing the contortionist routine and noticed that they were dangling in the path of the accelerator pedal mechanism and in some cases showed signs of chafing on the insulation. Another complete rework was in order and that slowed things down considerably. I'm happy with the results and especially happy that this time the compressor fired right up and pushed cold air through the vents as it was meant to.


With the ambient temperature showing 100 degrees F, at 50% compressor speed (which master mechanic Keith Jordan says shows ideal line pressures) the inside temp dropped to 94.1 in the first minute and 92.8 in the second minute. 



Probably more important, the chilled air blowing through the vents felt very comfortable and made the car a lot more civilized. The compressor is almost inaudible when running and its sound is masked by the radiator fans. In this short test, the motor and inverter temperatures held at around 39C, so the heat exchanger in front of the radiator didn't seem to have any effect on the running gear. Tomorrow we'll stress it a bit more and mix highway miles with some local traffic. It's forecast to be another 110 degree day, so we'll get a good sense for what it can do.

The PorschEV is inching towards completion and all-weather everyday use.