Sevcon Gen 4 Errors and Solutions thread

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oli_b   1 µW

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Re: Sevcon Gen 4 Errors and Solutions thread

Post by oli_b » Sep 19 2018 7:50am

Hello methods !

Sorry for turning to You directly, but I went through the whole internet and called all possible people but You seem to be the only one in this topic who really knows what he's talking about and digging deep enough...

I have a microcar type "Romet 4E" (You can check it in Google Images as it's most probably unknown to You) that uses a Sevcon Gen4 8035 Size4 controller. (setup is mostly the factory default single-traction-motor, but I could figure out some modding as well, although the flashed-in program is unknown. I contacted the manufacturer but they don't want to disclose information)

Original battery setup was 9pcs 8V 135Ah Lead-Acid, but I converted the car to Lithium (24pcs 3.3V 200Ah LiFePO4) for a much better performance, lower weight, and to extend the EV range to more than twice of the original.
So the system voltage went from nominal 72V to 79.2V (which is no problem for the 8035 as the nominal voltage is 80V and the maximal is 116V as far as I know). I also made some internal mechanical modifications but that's irrelevant at this time.

Now the next step to tune the car further is to extend the speed limit and improve the performance of the regenerative braking.

There are two RPM limits programmed into the controller, the one belongs to the "normal" driving mode, the other to the "economy" mode, which allowes You to drive (through the single fixed gear) 60km/h in normal mode and 40km/h in economy mode.
Certainly I never use the economy mode as it can be achieved by handling the accelerator pedal more gently, I use it for regenerative braking as switching the "eco" mode during driving brakes the car back to 40km/h using regenerative.
So my problem is obvious: 60km/h for normal driving is too slow, and braking back to 40km/h only is too less regenerative braking.
I would like to change the two RPM limits so that the normal limit is 80km/h and the economy limit is 10km/h, not because I want to drive 10km/h but this would allow me to make regenerative braking down to 10km/h instead of 40.
Also the 80km/h has some risk because of the fixed gear, it might over-RPM the engine, so I don't want to drive this speed continouosly, but every now and then there might be a need during overtaking to go faster than 60km/h to make the overtaking shorter.

On the default Gen4 setup there is no "normal mode" and "eco mode", so this must have been programmed by the manufacturer, and I was tracing back the wires and it turned out that the "eco-switch" is connected to "Digital Input #5" (pin 20) of the Gen4 connector: it is floating at high impedance (0.4 x Vbatt) when in "normal mode" and pulled down directly to GND in "eco mode". This pin20 must have been mapped to the "economy" variable inside the controller's program.
So far so good.

Now my idea is to use a ClearView display to program the RPM limit(s) if possible. But before I order such an expensive toy I would like to ask someone with experience (this means You) how the ClearView is working and whether it is possible to program the RPM limit(s) of the motor.
I have seen a YouTube Video (https://www.youtube.com/watch?v=2ryWTccXb-I) where some guy was changing the RPM limit of the motor (Menu-->Personalities-->Baseline-->Max Speed FWD), but my controller seems to be programmed to two different limits, and I don't know if it is possible to program more limits with the ClearView? May be this is solved by using the Profiles? (Menu-->Personalities-->Profile1 and Profile2), and the "eco-switch" is just switching between these 2 profiles?
I don't know as the video does not step into the Profiles1 and Profiles2 menu...

The other thing I would like to program with the ClearView is (beside the two RPM limits) is the efficiency of the regenerative braking. At the moment I am not satisfied with the braking power of the regenerative braking.
My suspection is that the "maximum deceleration rate" is limited in the controller, not to overcharge and blow up the original lead-acid batteries, as they can only be charged slowly with a smaller current. But now the car has Lithium that is able to absorb much more power and much more charging current, allowing the car to decelerate much harder, therefore the maximum deceleration rate could be set up for a higher value, so I could brake better with the engine and regenerate more energy instead of using the hydraulic brakes...

So any idea or suggestion or experience is very welcome that helps me further!
Thank You very much! (sorry for writing a complete roman out of it...)
---
Oliver

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sanfox   10 mW

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Joined: Mar 27 2015 12:14am

Re: Sevcon Gen 4 Errors and Solutions thread

Post by sanfox » Sep 20 2018 8:26am

Hello Oliver!
Can You save your dcf from sevcon and send it for me?
I will try to understand your motor parameters.
Also you has abbility to rise up votage to 100 V an example and take more power from your motor!
3250 km in hybrid mode
My car discription at http://www.evalbum.com/5316

oli_b   1 µW

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Re: Sevcon Gen 4 Errors and Solutions thread

Post by oli_b » Sep 26 2018 9:31am

Hello sanfox,

I have no any tools for the Gen4 controller, so I surely can not extract the data out of it...
My questions for the Gen4 in my previous post were to be able to decide if I should buy a ClearView Display, to be able to adjust some parameters.
The Gen4 came pre-programmed by the car manufacturer, who do not produce the car any more, and they refuse any help when I tried to get some over the phone...

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sanfox   10 mW

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Joined: Mar 27 2015 12:14am

Re: Sevcon Gen 4 Errors and Solutions thread

Post by sanfox » Sep 28 2018 1:17pm

Oliver, I can give you contacts of a guy from Poland, which has DVT dongle and his oun progect with sevcon powered car.
If you intresting that send me PM.
3250 km in hybrid mode
My car discription at http://www.evalbum.com/5316

oli_b   1 µW

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Joined: Sep 19 2018 6:52am

Re: Sevcon Gen 4 Errors and Solutions thread

Post by oli_b » Sep 28 2018 2:24pm

@sanfox
Thank You, it would be very good.
I sent You a PM.

Thanks!

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