Search found 421 matches

by zeva
Tue, 22 Jul 2008, 21:41
Forum: Electric motors and controllers
Topic: ZEVA controller?
Replies: 21
Views: 3091

ZEVA controller?

Not 100% sure on pricing yet, but I'm confident it will come in under AU$1500. And I promise it will be better than anything from Curtis http://forums.aeva.asn.au/smileys/smiley2.gif Here's some specs: - 144V 500A power rating (up to 750A to the motor) - Microprocessor controlled (with a bunch of sa...
by zeva
Tue, 22 Jul 2008, 21:03
Forum: Electric motors and controllers
Topic: ZEVA controller?
Replies: 21
Views: 3091

ZEVA controller?

Hi hyper24, Yep, the ZEVA controller is currently my #1 priority. I'm building the "production prototype" right now i.e physically and electrically identical to the intended production design, which will be going in the MX5 later this week for field testing. If all goes well, I'll get on with arrang...
by zeva
Tue, 22 Jul 2008, 17:17
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Here's the explanation on the likely cause of failure from the inimitable Lee Hart, as posted on the EV Tech list, seems to make sense: The Curtis 1231 has enough trouble running a 9" motor; I'd say an 11" is just too big for it. Direct drive puts even more load on the controller. You really need a ...
by zeva
Tue, 22 Jul 2008, 08:56
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Hi Tuarn, Yep, you're right, the difference in time taken for the electrons to travel to the other end of the case would be insignificant. But I'm sure I've heard that the distant FETs switch every so slightly later than the closer FETs.. Perhaps the slight difference in resistance between driver an...
by zeva
Tue, 22 Jul 2008, 05:07
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Yeah, also I'm not worth much (ahem, financially I mean) so there wouldn't be much point suing me. As they say, you can't get blood from a stone! Image
by zeva
Tue, 22 Jul 2008, 04:49
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

So I took apart the Curtis today to see what went wrong. For anyone interested in a bit of power electronics and controller design, here's a report on my findings: http://zeva.com.au/tech/curtis If anyone from Curtis is reading this.. Please don't sue me for bagging your product - direct your energy...
by zeva
Mon, 21 Jul 2008, 17:41
Forum: Batteries, charging, management and monitoring
Topic: ThunderSky vs Trojan
Replies: 6
Views: 1391

ThunderSky vs Trojan

Hi hyper24, You're omitting one major component to the economics equation: cycle life. Most people get about 300-500 cycles from Trojans in an EV. ThunderSkys have a cycle life of 2000-3000 cycles, and this has been independently verified by some well respected people (e.g Jukka Jarvinen of fevt.com...
by zeva
Sun, 20 Jul 2008, 18:01
Forum: Technical and conversion discussion
Topic: Loaner tools for AEVA
Replies: 7
Views: 1365

Loaner tools for AEVA

Hi all, In the interest of removing one more hurdle for EV converters, I've decided to donate a few parts to the AEVA community: 1) Cable cutters and hydraulic crimpers It's pretty critical to use the right tools when wiring up your power circuit (to make sure you don't introduce parasitic resistanc...
by zeva
Sat, 19 Jul 2008, 16:21
Forum: EV Motoring
Topic: Al Gore's new speach, a call for electric cars
Replies: 3
Views: 1009

Al Gore's new speach, a call for electric cars

What a great speech, Al Gore is a champion. Here's a link to the video for anyone else too lazy to read ;) http://www.youtube.com/watch?v=dt9wZloG97U It really reiterates to me the importance of the EV movement. (And inspires me to try doing more for the planet - after all, EVs are just one part of ...
by zeva
Sat, 19 Jul 2008, 15:36
Forum: General EV Discussion
Topic: First EV
Replies: 31
Views: 2945

First EV

I'll offer my 2 cents on this one.. Yes, contrary to popular opinion the (correctly-named) spoilers fitted to many roadgoing vehicles are not for downforce but are there primarily for disrupting (spoiling) the vortices off the rear of the car, to reduce drag. Interestingly, vortices are usually wors...
by zeva
Sat, 19 Jul 2008, 15:18
Forum: General EV Discussion
Topic: Motor Adapter
Replies: 5
Views: 755

Motor Adapter

Hi Taffy, Option A is by far the most common choice. The easiest way to go is to pull the old clutch plate onto a lathe and cut out the middle which has the spline fitting to the gearbox (splines are a huge amount of work to machine yourself, easier to hack up the clutch and use the existing parts!)...
by zeva
Sat, 19 Jul 2008, 05:07
Forum: Batteries, charging, management and monitoring
Topic: My bat calcs correct?
Replies: 8
Views: 1209

My bat calcs correct?

OK since you asked... Brace yourself for some physics & maths! The kinetic energy of a moving object E = 1/2mv^2, so a 1000kg vehicle has about 380 kJ (kilojoules) of energy. The rate the vehicle gets to this velocity is determined by the power from the motor where energy = power x time. But for ste...
by zeva
Sat, 19 Jul 2008, 04:08
Forum: Batteries, charging, management and monitoring
Topic: My bat calcs correct?
Replies: 8
Views: 1209

My bat calcs correct?

EDIT: Looking at the thundersky bats with stats LFP90AHA       3.2V       90AH       270A       2000       220x145x68       3.0kg If I have 35 of them thats 112V, 112v*90AH = 10.1kw Considering these a lipo bats, what factors do I have to consider in, how much of this power is usable and what is a ...
by zeva
Sat, 19 Jul 2008, 04:01
Forum: Batteries, charging, management and monitoring
Topic: My bat calcs correct?
Replies: 8
Views: 1209

My bat calcs correct?

If i only want the car to run at 70ks top speed, what calcs do i need to do. Do i need to see what revs my car does at 70ks and try to match that to a motor with the lowest voltage possible but also providing enough torque? It's kind of hard to calculate, but to work it out correctly you have to wo...
by zeva
Fri, 18 Jul 2008, 22:51
Forum: Batteries, charging, management and monitoring
Topic: My bat calcs correct?
Replies: 8
Views: 1209

My bat calcs correct?

Range is hard to predict exactly/mathematically, but easy enough to estimate based the efficiency observed in similar vehicles previously converted. Via the latter method I can tell you you'll average about 150wh/km in a Barina, if everything is working as it should. Are you familiar with Peukert's ...
by zeva
Fri, 18 Jul 2008, 16:35
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Lithium batteries, no they don't have to all be adjacent to each other (I have a split pack in my MX5) though if it's possible to keep the pack in one block, it is better. Partly the BMS can get confused if its signal wires have to travel too far between packs (in an electrically noisy environment),...
by zeva
Fri, 18 Jul 2008, 06:13
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Yeah, go the 205 GTi conversion! That would be a great little EV! And I'll do an RX7 conversion, and we'll see who can complete The Sideling quickest. Sounds to me like that RX7 driver just lacked the necessary cojones if he couldn't handle his RWD in wet weather http://forums.aeva.asn.au/smileys/sm...
by zeva
Fri, 18 Jul 2008, 04:53
Forum: General EV Discussion
Topic: First EV
Replies: 31
Views: 2945

First EV

Hi Paul, A man after my own heart - I'm a self-professed electric revhead as well http://forums.aeva.asn.au/smileys/smiley1.gif 1) Gearboxes.. if you're using the right equipment, you (a) won't need a gearbox and (b) would destroy anything between the motors and the tailshaft anyway http://forums.ae...
by zeva
Thu, 17 Jul 2008, 17:31
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Yeah while nobody would recommend the Curtis 1231C for direct drive applications, it is disappointing that their design does not accommodate sufficient self-protection mechanisms for it to shut down gracefully when overworked instead of just dying! Logisystems in the US have recently been refurbishi...
by zeva
Thu, 17 Jul 2008, 16:06
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

So.. Lesson Learned The Hard Way #572: Curtis 1231C controllers do not like running big motors direct drive. About 5 minutes from home last night it had a strange shudder then died. I got a friend to help me tow it back the rest of the way, and once I got back to my multimeter was able to confirm th...
by zeva
Thu, 17 Jul 2008, 01:06
Forum: AEVA WA Branch
Topic: Perth Branch Meeting
Replies: 11
Views: 3566

Perth Branch Meeting

Contact Dave Walpington (WAEVA chairman) for the login code to the live stream:

http://www.waeva.asn.au/contact_us.asp
by zeva
Thu, 17 Jul 2008, 01:05
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

A belated update on the MX5, with some pics of the progress up to the first test drive last week: http://www.zeva.com.au/conversion_blog.php?vehicle=1&post=14 It's still not quite licensed but I've got a temporary movement permit for it at the moment so will bring it down to the WAEVA meeting tonigh...
by zeva
Wed, 16 Jul 2008, 18:34
Forum: General EV Discussion
Topic: vehicle modification
Replies: 1
Views: 485

vehicle modification

Hi all, Yes I meant to reply to the vehicle immobilise question mentioned in the last WAEVA newsletter as well.. The good news is there's really no magic involved with immobilising an electric car. Usually you'll use the vehicle's old ignition wire, which goes from the steering column to the engine ...
by zeva
Tue, 15 Jul 2008, 04:12
Forum: General EV Discussion
Topic: Overall Initial Calculations
Replies: 20
Views: 2325

Overall Initial Calculations

OK your math is correct but I think some of your initial assumptions are incorrect: (a) Your running costs for petrol power does not include the amortized cost of destroying the planet ( http://forums.aeva.asn.au/viewtopic.php?t=334 ) (b) You'll usually be charging at night, where off-peak electrici...
by zeva
Tue, 15 Jul 2008, 02:31
Forum: Technical and conversion discussion
Topic: Progress on the MX5 conversion
Replies: 50
Views: 9485

Progress on the MX5 conversion

Now that the MX5 is all up and running, I thought I'd extend an open invitation to anyone interested in coming to take it for a drive - just drop me a line. Especially people who've never driven an EV before as hopefully it'll (a) make you want one and (b) make you wonder why we still can't buy prod...