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Mercedes A and B class donors; stability control

Posted: Mon, 10 May 2010, 07:25
by marcopolo
A Mercedes 'B', EV taxi is destined for production 2010. Not very impressive range though.
Autoevolution wrote:A special electric vehicle test program is taking place in London, where a research version of the Mercedes Vito Taxi has been developed by a tie-up between multiple British companies over the last six months. The vehicle, partially funded by the UK Government’s Advantage Niche Vehicle Research & Development Programme, meets the London Carriage Office requirements, can accommodate up to six people and offers a range of over 120 km on a six-hour charge.

Called the E-Vito taxi, it uses a 70kW (95 hp) electric motor, already introduced on the market by Zytek, that uses a tailor-made Vocis gearbox supplied by Graziano. The electric unit is powered by a 35 kWh Valence Li-Ion battery pack, installed beneath the vehicle’s floor (this lowers the car’s center of gravity, improving its stability). The E-Vito uses a steerable rear axle, which provides the 7.6m (25ft) turning circle required by all licensed black cabs in London and a front drive conversion that increases the interior space.

The electric motor is installed on the original engine mounts and requires additional water, high voltage electrics and low voltage electrics connections. The highly innovative system communicates with all the vehicle’s factory systems, ABS (Antilock Braking System), ESP (Electronic Stability Program) and OBD (onboard diagnostics).


Mercedes A and B class donors; stability control

Posted: Mon, 10 May 2010, 15:25
by Johny
A very pessimistic range figure (120km) for a 35kWh pack - especially at taxi (city) speeds? Nice that the converters were apparently handed the ABS/ESP, OBD interface specs by the auto manufacturer.

Mercedes A and B class donors; stability control

Posted: Mon, 10 May 2010, 16:49
by marcopolo
Johny wrote: A very pessimistic range figure (120km) for a 35kWh pack - especially at taxi (city) speeds? Nice that the converters were apparently handed the ABS/ESP, OBD interface specs by the auto manufacturer.


Yes, but it is powering a very sophisticated drive train set up. I am not sure what the Black Cab zoning restrictions are, but perhaps 120 klm, is a lot for such a congested city. (lot of idling, great for EV, lot of stop/start not so great).

Obviously Mercedes are preparing to meet the challenge from the original Back Cab company now that it has been bought by the PRC manufacturer, Geely. (along with Volvo cars).

Interestingly, Ford Europe do not have much impact in the UK taxi fleets, the way they do in Australia. The Ford UK model is basically a small Ford Transit, running on CNG. (although an EV is available).

Yeah, the ABS/ESP, OBD interface specs! Sigh, if only a copy was available.

Mercedes A and B class donors; stability control

Posted: Thu, 20 May 2010, 08:59
by rhills
Nice-looking Merc A-190 potential donor on eBay here, especially if you're in QLD. What was the consensus on the ABS and conversion? Is it a go or no-go, or does it depend on which (nanny) state you live in ATM?


Mercedes A and B class donors; stability control

Posted: Thu, 20 May 2010, 14:44
by coulomb
rhills wrote: Nice-looking Merc A-190 potential donor on eBay here, especially if you're in QLD.
Yes, thanks, it does look nice, for an older model (the only type I could afford). It says "automatic transmission", but this could be the clutchless manual, I can't tell for sure but it looks that way to me.
What was the consensus on the ABS and conversion? Is it a go or no-go, or does it depend on which (nanny) state you live in ATM?

Well, I didn't say, because I don't know.

The subject of ESC/ESP (Electronic Stability Control) came up after last night's meeting. My recollection (please correct if wrong) is that Queensland is following Victoria's lead (!) on requiring ESC on all new vehicles from 2011. How this applies to conversions is unknown. At this stage, I'd guess that ESC could be omitted from conversions older than 2011 and still pass ADR. In about 5 years time, the NCOP will be replaced with the new ADRs, and the equivalent of NCOP will become explaining how and why you want to depart from the ADRs for new cars with your modification (be it electrification or modified engine, suspension, etc).

So there is likely a ~~ 5 year window for "easier" conversions, possibly excepting Victoria, but that's far from clear to me.

But you actually mentioned ABS, which would be a rather good thing to retain if possible. The legality and safety of ABS with altered weight distribution and feeding it just motor RPM in place of engine RPM, and doing "something useful" with the CAN commands to reduce or eliminate engine power, is something I'd have to research carefully. But I believe that most modern conversions would have this situation, so surely someone has solved it somewhere.

Mercedes A and B class donors; stability control

Posted: Thu, 20 May 2010, 15:33
by coulomb
coulomb wrote: But you actually mentioned ABS, which would be a rather good thing to retain if possible. ... But I believe that most modern conversions would have this situation, so surely someone has solved it somewhere.

It seems that a handful of conversions have ABS from the donor vehicle, and ABS is mostly independent of other vehicle computers.

http://auto.howstuffworks.com/auto-part ... brake1.htm

Converters report that they still feel shuddering of the brake pedal when the ABS kicks in. I think that that should satisfy a certifying engineer. Of course, fancier ABS systems may attempt to change the engine power.

The other thing is that in an A-class, the ABS and ESP systems appear to be integrated. So I think I'm finally starting to see the problem.

Mercedes A and B class donors; stability control

Posted: Thu, 20 May 2010, 16:18
by coulomb
This is nowhere near definitive, but it's looking hopeful to me:

Image

This is the ESP/ABS/etc unit. It seems rather self contained, and rather than using a can bus and power connector, connector A seems to have about 20 wires. B and C seem to be cables going direct to sensors, not via the CAN bus. But I'd need to see a wiring diagram to be sure.

From Lofy's page, as usual. Thanks, Lofty!

Mercedes A and B class donors; stability control

Posted: Fri, 16 Aug 2013, 04:37
by tassie_tiger
Some of A Class's are now sub $5000, eg:

http://www.carsales.com.au/private/deta ... 46&sdmvc=1

Mercedes A and B class donors; stability control

Posted: Wed, 21 Aug 2013, 16:04
by tassie_tiger

Mercedes A and B class donors; stability control

Posted: Wed, 21 Aug 2013, 16:33
by Johny
I couldn't find any mention of ESC. Going by the amount of aluminium oxide on the ICE that was pulled out they may be pre-ESC cars that they have done so far.

Mercedes A and B class donors; stability control

Posted: Wed, 21 Aug 2013, 17:43
by woody
There is a converted A or B Merc in sydney near me, I've only seen it in traffic...

Mercedes A and B class donors; stability control

Posted: Thu, 22 Aug 2013, 06:44
by Shirker
woody wrote: There is a converted A or B Merc in sydney near me, I've only seen it in traffic...

Is it Lester Clifford's?
See this YouTube video for more...
Does anybody know Mr. Clifford, or have his contact details?

One of the main folks involved on that Swedish site seems to be from Wellington, NZ...

[Edit: "Mr."!]

Mercedes A and B class donors; stability control

Posted: Fri, 30 Aug 2013, 21:27
by Lester
Well guys it is Lester here with the B class. Woody sent me a text and I have been slow to respond...sorry. BTW Woody how is the Cortina conversion going? the B class has been the daily driver now for nearly 4 years. 30000km notched up and in that time changed front brake pads and fluid and one T/S battery. One of my over 100 charge regs failed early on and I did not notice until too late. Otherwise it has given no problems.

To your real questions:
1) Excellent donor really. My wife drives a diesel B class and mine handles better. All the weight (extra 200kg) is way down and in the middle. The stability control is disconnected and certainly not required and the inspectors did not bat an eyelid...mind you mine was finished before the vic rule someone mentions
2)Easy adaptor plates and mounts and battery placement

By the way if anyone would like the alu endplates that come with packs of batteries I have lots that you are most welcome to have

Mercedes A and B class donors; stability control

Posted: Sun, 01 Sep 2013, 03:47
by Shirker
Hi Lester, and thanks for joining in! (And thanks Woody!)

I love your car - it sounds like it's been good fun. Can you elaborate on how you dealt with all the CANbus systems? e.g. how did you deal with the ECU?

Regarding ESC, the success of your approach is good news. Though I'd love to preserve MB's safety systems, it seems like a worthy compromise.

According to this Explanatory Statement of Vehicle Standard 2009, ESC became mandatory for new models on 1/11/2011 and will be for all new cars from 1/11/2013...

So does that suggest that conversion of a pre-2011 model would be allowed under AVSR/NCOP-14 with ESC disabled?

Mercedes A and B class donors; stability control

Posted: Mon, 02 Sep 2013, 02:13
by Lester
You may laugh at this and fair enough.... After testing I threw the ECU away! (Actually I traded it at the wreckers for some parts but the idea is the same). Without the ecu the power steer works as does the abs (pulsing on gravel). This is a safety thing. If the ecu fails the last thing merc wants is an unsafe car lawsuit and the car would be if suddenly mid drive the steering went. A warning light comes on (take out bulb) and a drive to garage message on startup appears (turn off)....so easily fixed. As you can see I approached this with a can do attitude and was determined to impress the engineers with a well built fait accompli rather than as a problem to solve. Worked for me but obviously may not work for all....