Adventure EV

It Lives!!!!! (sort of…)

by on Dec.15, 2010, under Electrical, Motor

OK, so it’s been a while since my last post, a post which appeared to indicate that a full on road test of the EV Land Rover was imminent.  Here’s what happened…

It lives!  Though, maybe the above pic is false advertising.  That wasn’t quite taken from the EV Rover.  But it was taken nearby.

For about 12 miles, that’s what driving the EV Rover felt like.  Unfortunately, it was late in the day and I failed to record the moment on video.  Or in pictures.  So, you’ll just have to take my word for it.

Acceleration

Without any real quantitative measurements my seat-of-the-pants results feel as good or better than predicted.  The Rover will accelerate quickly to its top speed of about 55 mph all the while in 3rd gear, requiring no shifting.  I could, if desired, drive everywhere in this one gear as long as I don’t need to go faster then 55mph, at which time the rpm hits the motor’s limit.  That’s the weird/neat thing about electric drivetrains.  They have so much torque that first gear certainly becomes unnecessary, but in some cases the use of most gears becomes unnecessary.  And since the motor stops without power, I don’t even need to use neutral to come to a stop.  In this respect, driving a EV is like driving an automatic.

The truck will go faster…  shift into forth and I can easily hit 65mph while consuming a reasonable number of amps.  There’s easily more speed in it, but the road I tested on couldn’t support anything faster than a brief spurt to 65mph.

Slot the gearbox into second and the acceleration from a dead stop to the gear’s limit of about 40mph is electrifying (bad pun, sorry).  It’s hard to describe it.  The torque is ever present as soon as the accelerator is dropped, and the truck just goes!  While a conventional vehicle revs its engine, launches, and eases away, the EV just… goes.  No drama, just surfing a giant wave of intoxicating torque.  The lack of drama may seem uninteresting, but it’s anything but.  It’s a completely different experience that is no less exciting…  I mean, it just GOES!!! I’m guessing the acceleration in second gear would extrapolate to an 8 sec 0-60mph time if I could do it all in one gear.  At about three times quicker than normal, that’s essentially insane for a Series Land Rover.  It seems to pull about as strongly as my Callaway Range Rover, a 4.6L V8, in first!  I don’t know how much the gearbox will take… I imagine it’s not good to regularly practice that kind of performance with the stock box… or axles.

Running the same test in first gear would probably result in uncontrollable wheelspin and surely break driveline items.

With the weight of the batteries located so low in the vehicle, the Rover feels more planted than it did before.  It doesn’t roll as much.  I was lucky enough to have installed 109″ Station Wagon HD springs on the rear a long time ago.  While this choice resulted in a “rear up” attitude at the stock weight, the additional EV weight causes the rear to settle nicely, leveling the chassis.  The overall ride also becomes smoother, and traction over the rear has improved.  This is very noticeable when ascending the hills on our gravel/dirt road.  I have yet to determine the final conversion weight…

Range

What about range?  Hard to tell without some long-term testing.  The first thing I will upgrade is the tires.  I’m currently running really, really old off-road biased tires that are no doubt sapping large amounts of energy in the form of rolling resistance.  Over the 12 miles, I tested acceleration with average speeds around 45 mph I consumed 20 amp/hrs.  That’s about 1/6.5 of the pack’s storage capacity if discharged to 80% DOD, or a total range of 76.8 miles.  Discharge to 90% DOD (which is entirely acceptable with LiFePO4 cells) and I’m looking at around 86 miles of range.  Real-world testing will reveal more.  New lower rolling-resistance tires will increase that range figure.  And not trying to out-accelerate its big brother at every opportunity should lower the electrical consumption!

So the performance and range is bang onif not better than predicted and desired.

Having said all that, surely it’s been a couple of months since that last test drive?  Well, yes…  and here’s where I will reprise the phrase…

The Good, The Bad, and the Ugly

Keen followers will remember that I used this headline at the start of my conversion in reference to a leaking clutch.  Conveniently sandwiching the project, I use the headline again.

The Good… I just told you about the good.  The EV Rover works!

The Bad… More accurately, the EV Rover worked…  for 12 miles before it came to a dead stop on the side of the road.  On the way back to the house, under fading light, I witnessed some sparking through the engine-bay aperture that would normally be covered by the bonnet.  And then all was dead.  I rolled to a stop, pulled out my multimeter and started doing some rudimentary tests: Log in to motor controller via laptop…  controller seems to be working.  Check state of battery pack… battery pack is not shorted and outputting full system voltage.  Hmmm…  Feel HV wiring… room temperature.  Nothing out of the ordinary here.  Check the motor temp…  a few degrees above room temp.  No problem there…  Fuses… intact.  Puzzling.

With the help of a gracious neighbor (thanks Barb!) I retrieved the Range Rover and towed the EV back to the garage.  Further inspection revealed…

The Ugly…  Apparently one of the primary power cables inside the motor shorted apart by rubbing on the commutator!  Ironically, the most reliable part of the system failed.  And not because of anything I did!  That’s just weird.

Here's what the wire shorted on. The commutator.

That’s pretty ugly, isn’t it?  Fortunately, it doesn’t appear to be too bad.  Luckily the cable can be removed without disassembling the motor, and the commutator looks clean (aside from the carbon dust).  I removed the bad cable and jumped with another test lead, attached a 12v battery to the motor terminals, and thankfully saw the motor spin back to life!

This is definitely unusual.  Apparently someone at the factory may have forgotten to secure the cable with a simple wire tie.  Well, they say the devil’s-in-the-details, and this is certainly a prime example.  Kostov, the manufacturer, has been very easy to work with in this matter even though they’re located in Bulgaria.  They’ve already sent me a replacement cable!

But I’m not around right now… I’m back in California until the spring.  So there the EV Rover sits, its front up on jackstands, its motor awaiting a little surgery…

Projects never really end… do they?


12 Comments for this entry

  • Tom Williamson

    I’m happy and sad for you. And glad to hear you’re using jackstands 🙂

  • Charles

    Nice to hear it wasn’t a big issue and didn’t cause any damage. It’s *killing* me that you won’t be back at it until the spring though!

  • corbin

    Bummer about the motor, but that is great news that they already sent you the replacement part. I’m sure you’ll have it running again as soon as you are back.

    corbin

  • Michael Hudson

    Wow, I’m sorry to hear about your terrible luck. But I’m glad the performance was better than expected, even if it was short-lived.

  • Stephen Hobbs

    Just stumbled across your amazing blog while looking for EV info. What a coincidence, I’ve got a series 3 Land Rover which I also plan to convert to full EV spec.
    Now watching your progress with baited breath!
    Good luck for the final hurdle…
    BTW, how much did you spend on those batteries? In the UK it looks like that capacity would set me back ~£50k!

  • jeffg

    The batteries were expensive… but not THAT expensive. It really depends on the chemistry chosen. In this case, I’m using large, prismatic, LiFePO4 cells from Thundersky. At the time, each 160 amp-hour sized cell was about $176 each, and I ordered 64 of them for a total power capacity of around 33 kWh. It’s one expensive gallon of petrol, to be sure, but not quite $80,000 USD (at today’s rates), more like around $12,000 USD (~£7500)

    Of the lithium chemistries, prismatic LiFePO4 is definitely one of the most inexpensive. The trade-off is a relative lack of power density. The pack is “cheap”, but not light, at 360Kg (790lbs). Moving to another chemistry, like Lithium Cobalt (LiCoO2) would lower the weight of the pack to around 280 Kg (616lbs) for the equivalent amount of power capacity, it would be physically smaller, but it would also cost significantly more.

  • CocoEV

    Great project and blog entries! I must concur with the observation that choosing the right donor has got the utmost priority in the planing stages of such ev conversion. Your batt. pack solution seems as sure bet for increasing the longevity of the pack. You can perhaps later add amphenol connector to each batt. box for checking up individual voltages, Jack Rickard style.

    More importantely, there are not that many 4WD donors available without doing serious compromises. Basically it narrows down to Landrovers/Defenders, Jeeps and some russian hardware like UAZ. Otherwise there is nothing much left even to consider as serious donor candidate in that area. Sadly, Ford, Toyota and Nissan got overbloated over the years.

    Plus, what perplexed me is the fact, the community behind Landrovers seems to be pretty livly around the globe, e.g. you can even get a brand new galvanized frame, basically building the donor up from completely/mostly new parts! Check the link (it’s younger model w. lot of addons and luxury trinkets, but the bottom message is clear – very good donor platform): http://www.eastcoastrover.com/143.html

  • jeffg

    Thanks for the kind words! The Land Rover has proven to be a very worthy chassis, if not exactly the most efficient.

    However, it is somewhat of a unique platform these days. The ladder chassis makes experimentation easy, safe, and strong.

    And yes, I rebuilt mine from the wheels up with a new galavanised chassis well before the conversion. It’ll last forever! And now that it’s powered by a simple electric motor, that too will last well into century.

  • CocoEV

    Speaking of the longer 110 version, what is your take on the idea perhaps fitting some of the batts directly inside the ladder chassis (not “externally” running parallell as in your shorter chassis), it seems this is a possibility. Is is a realistic proposition, thanks?

  • Joe Ward

    Nice work Jeff! How about an update on your longer term experience with your electrover — now that it’s been running for 5 months or so? Thanks!

  • Will and Hunter

    My son Hunter and I have a series iia 1971. He just turned 16 last week, gets his license this week, and is going to drive our series back and forth to school. Round trip seven miles. He has his petrol version rebuild from the ground up now complete, with one exception. The engine has a crack in the block, thus the interest in “electrifying” the series. Not to mention he would get to park it close to the school in a slot for electric vehicles. Can you do another post and update us on what’s happening now and any advice for a guy like Hunter? One might be – get an EE degree, first:)

    Best,
    Will

  • Mike

    I was wondering if there were any new updates!?!?
    Did you get the new cable? Are you back up and running?
    Want to sell those batteries!?!? (jk)
    I would love to see some videos of your rig going off road.

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