Recent Kite-EV conversion tech notes in emails relevant to W&I Car Challenge, that cover ABS/TCS interference and work-around.
JohnB is a longtime KiteLab/kPower consultant-collaborator, who engineered and built our first instrumented groundgen unit around 2008. He founded and runs an aerospace test engineering practice that qualifies satellite hardware, and owns a Tesla. He helped pioneer legal DIY renewable grid-tie in Texas, creating his own solar farm with tracking panels, and is one of AWE’s great low-key talents. Emails run last to first-
From: dave santos santos137@yahoo.com
To: John Borsheim
Nov 16 at 5:45 PM
Hi John, Yes, very helpful, sorry for the delayed response.
I had not thought of ABS and TCS interference. The quick and dirty work-around is to remove those fuses to disable. A custom master-switch can isolate all complex EV functions to activate only primary charge-control, maybe including added surge protection. Current EVs shut out surge to activate mechanical braking.
Each EV design has its own trade-offs. Its looking like a cheap salvage early generation EV, maybe even with lead-acid storage is a best start, since initial kite-EV integration is primary research. Electric golf carts often have regen brakes these days. Let advanced EV integration come later, in optimization phases.
dave
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On Wednesday, November 20, 2019, 08:24:25 PM CST, john borsheim wrote:
I believe that I can help with specifics, but I don’t quite know at what level you need.
Let’s take the tesla, for example. Single motor cars are rear wheel drive using a differential. The all wheel models have one additional motor for the front wheels also using a differential. There is no transmission, all speed variation is done using a variable frequency inverter.
Let’s use an example of jacking up one rear wheel and driving it to charge the battery. I’m not sure if the traction control system will play along. For all acceleration and deceleration modes, the traction control system is checking the speed of all 4 wheels and may totally freak out if it sees only one wheel spinning. What will it do? I don’t know, possibly just let it spin, without regen.
Generally regen provides much less deceleration than you can get during acceleration. At 60 mph and higher, the regen is 60kw. for all speeds below 60, the rate is linear: 50 mph is 50 kw, 30 mph is 30 kw, etc.
As far as overcharge and battery protection goes, the battery management (bms) kicks in and limits the regen levels. For example, on a cold morning, there may be little or no regen, and the lower limit and warnings are indicated in the instrument cluster. As the bat pack warms up from driving, the regen limit increases to normal ar 60 kw. Of course, if the battery gets totally recharged, the bms limits or ceases regen.
I hope that helps. Please let me know if that answered your question, or not, lol…
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From: dave santos santos137@yahoo.com
Sent: Saturday, November 16, 2019 5:45 PM
To: John Borsheim
Subject: Tesla Regen Braking Questions?
Hi John,
Have been slowly figuring out regen braking details for various EVs for kite-driven mode, no two makers are exactly the same. The best EV regen is automatic, smooth, and efficient. It must never overheat the gen nor overcharge the battery. Tesla is reported smooth compared to most other EVs, but many details are hard to find.
The questions here are general, about key specs of hacking interest, like interdependent numbers for max-gen-mode wattage, lowest max-charge vehicle velocity, brake-hp, charge efficiency, etc. (?)
Note default kite input by jacking up a drive wheel, with Kite PTO capstan pully on lug bolts, as roadable after charging. Some EVs are individual motor-wheels, others are differential transmissions. Seeing dirt-cheap used 1st-gen EV salvage market emerging, with de-rated or no batteries, and ESC electronics aftermarket choices.