Here at Transport Evolved we pride ourselves on the fact that everyone on the editorial team — and those who regularly contribute as guest posters — all own or drive some form of alternative fuel (or evolved) vehicle. Spread over two continents and three time zones, our editorial fleet is primarily made up of modern electric cars like the Nissan LEAF, BMW i3 and Smart ForTwo ED. Owned and operated by individual writers, we share our everyday ownership experiences with you to educate and inform in the hope that our readers will learn from the things we’ve learned — and that you’ll avoid any of the mistakes or problems we’ve experienced.
But as regular readers will know, our staff car fleet also includes an internal combustion-engined classic car awaiting conversion to electric, a first-generation Honda Insight and our most recent addition, a 2002 Toyota RAV4 EV. While the majority of our readers look to us for information about the latest and greatest in cleaner, greener, safer and smarter cars, our older iconic vehicles allow us to connect with some of the most influential cars of their generation. By driving them today, we’re not only keeping history alive but also learning more about what made these cars so special, getting our hands (a little) dirty with some honest DIY maintenance, and showing those who can’t afford a brand-new car that there are other ways to own a cleaner, greener car.
Last month, we officially took ownership of ‘Sparkie‘, a 2002 Toyota RAV4 EV. Produced between 1997 and 2003 as a ‘compliance’ car by Toyota in order to satisfy California’s first zero emission mandate, Sparkie is quite a rare beast. That’s because while Toyota made 1,500 or so RAV4 EVs during the car’s production run, only 350 or so were actually sold to customers. The rest were leased and subsequently crushed at the end of their life (as chronicled in the film Who Killed The Electric Car?).
Our goal? To restore Sparkie (as named by her former owners) to her former glory, and use her as a daily driver on the Transport Evolved Fleet. At the same time, we hope to chronicle some of the challenges and joys that come from owning one of the most influential electric cars of the early noughties.
When we last gave you an update, Sparkie had just arrived at Transport Evolved’s Portland headquarters and been given a new 12-volt accessory battery to ensure that we could at least try to figure out where the problems lay. After driving around the private residential roads that surround our office, we were able to use the tried-and-tested ‘paperclip method‘ of retrieving error codes stored in the car’s memory.
It made for some depressing reading. With a pen and paper in hand, we recorded the number of flashes on the car’s various display lights and then looked them up in the factory repair manual that came along with the car. This is what we found:
- C2822 – Leakage Signal Circuit Malfunction
- C2842 – Input Voltage 1 Malfunction
- C2171 – Motor Inverter Over Voltage Signal Circuit Malfunction
Like a patient with just a little too many terrible medical conditions to choose from, our subsequent investigations led us to a bevy of potential problems with the car, some of which — Toyota’s manual seemed to suggest — would require expensive replacement of a massive number of parts. With such a tight operating budget for both the site and the car, things weren’t looking great.
We even wondered if we’d have to give the project up.
That was until someone on the very informative classic RAV4 EV owners mailing list suggested that these errors may have been triggered by a faulty 12-volt accessory battery. Suggesting we reset the errors and cross our fingers, we were told that the errors would only reappear if the 12-volt battery wasn’t the seat of the problem.
Luckily for us, they didn’t.
In the meantime we were able to obtain a diagnostic cable allowing us to connect a laptop computer to the RAV4’s on-board diagnostics system, as well as a period Palm Pilot PDA and RAV4 INFO cable (thanks to two awesome readers). The former allowed us to use Toyota’s official diagnostics software to look into the car’s brain, while the latter allows us to keep a close eye on the car’s battery pack.
Both agree on one simple fact: one of the 24 battery modules in Sparkie’s battery pack (each with 10 cells in each) is a little sickly. The rest are fine. If we had to guess, we’d say that two of the cells in that faulty module have shorted out, resulting in a lower-than-normal voltage on that one module. And that, it appears, was what was causing all the issues with warning lights, turtles and more.
Given the car was donated to us and NiMH battery packs are rather expensive and hard to get hold of, we decided to see if we could resurrect the dead module. Through a series of short charge cycles (less than 30-seconds each) we were able to slowly raise the voltage of the car’s battery pack. At the same time, super-short trips around TE headquarters was enough to warm the weak cell up enough to begin to take a charge.
After a week or more of carrying this cycle out, Sparkie began to show signs of range. While the weak battery module was still several volts under the rest of the pack we were able to (gently at first) exercise Sparkie on increasingly long low-speed trips.
As the battery started to wake up, the power we could drain from the pack started to improve, caused in part by increased temperature. And we soon realised what the issue with the pack was. According to Toyota’s diagnostic software, the internal cell resistances of each module were rather high, meaning that at cold temperatures it’s particularly difficult to draw power from the battery pack. But as the battery modules warm up through gentle use, their internal resistance start to drop. And thus, more power and more range became available to us.
With a carefully-planned route, we headed to the local DMV. A fourteen-mile round trip with more than 560 feet of climbing, we have to admit we were worried about the trip. But careful acceleration on slow surface streets rewarded us with not only a round-trip but a new set of license plates on the way. We’ll leave the exact license plate details for another post.
Now that Sparkie was registered for the road, we were able to start pushing how far it could be driven, all the time ensuring that the weakest battery didn’t drop below the dangerous 10-volts off-load considered to be the empty voltage for heavy power drain. With every trip, the car seemed to wake up a little more and the real-world ‘ideal’ range improved. By the time we’d covered several hundred miles, Sparkie was happily covering 25 miles with careful accelerator use and we’re trying to use her daily to ensure her battery pack stays in the golden zone — human body temperature.
At this point, there’s something of a disclaimer. We’re not engineers, and we know that some of the things we’ve done thus far aren’t the official, recommended practices for a car with a weak cell. Indeed, we understand that it could, if we’re not careful, accelerate the beginning of the end for the weak battery. But we also know that NiMH battery chemistries are incredibly robust and we’ve seen evidence (both first and second hand) that suggests what we’re doing could buy us a little more time until we have to invest in a replacement battery pack.
Talking of which, we think we may have already sourced one. Through some contacts in the electric car enthusiast world, we’ve heard of a crate of EV-95 NiMH batteries that have been saved from recycling and are being tested for their suitability to be used once again in an electric car. Once we have word that replacement batteries are available, we’ll put into motion a plan to bring Sparkie to a workshop where we can safely drop the battery pack, clean it, and replace the weaker cells with suitably matched ones. Either that, or replace the battery pack with a lower-resistance, matched pack of better health.
Over the past few weeks, driving Sparkie on an almost daily basis has let us grab a laundry list of other things that need to be fixed. The most pressing is the windscreen.
After nearly 14 years in the Southern California desert, Sparkie’s windscreen is covered in thousands of tiny sand pits from sand storms, leaving the surface less than stellar. Aside form causing the wiper blades to skip sometimes, the screen isn’t ideal for use at night time (something we’ve yet to worry about because we’ve used the car during the day).
Replacements are apparently available for around $600. Part of the high cost coming from the fact that the early 2002 RAV4 EVs had a fully-heated windscreen enabling defrosting on cold winter mornings. Since most RAV4 EVs lived in temperate California, that feature was dropped for 2003 model cars. We’d like to keep things fairly stock if possible, so we’re now saving up for that all-important screen.
The bodywork and lights have also suffered at the hands of desert sand storms, meaning we’ll be taking some time over the next few months to carefully restore the body and lights ahead of next winter. In the meantime, we’re keeping our eyes out for the spare parts we need on auction sites. Our actual list of things to fix is substantially longer than the highlights we’ve just given you, but you can be sure we’ll be adding more bits and bobs to fix in the coming months.
In the meantime, if you happen to be one of our readers from Portland, OR and happen to see Sparkie out on the road, don’t forget to wave!
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