Regenerative Braking Not Working?

Hi, I didn't see any other topics/posts around this, and I'm hoping for some insight from other i-Miev owners (my local dealership is no help).

About a year ago my main battery was replaced (under warranty). Prior to that my range was steadily becoming abysmal and I had difficulties getting it to charge.

After the replacement, most of the problems went away, but my range is still pretty bad. For a while I chalked it up to my teenager not really driving in the most efficient manner, but I've been driving it more lately, and no matter how careful I am, I can't get more than about 18 miles out of the thing. When we first got it (5 years ago) I would routinely get ~50 miles.

Since the battery was just replaced, I'm reasonably certain that's not the problem. Is it possible that the regenerative braking isn't working? If so, how can I tell/troubleshoot that? Is there some sort of maintenance I can/should be doing on that?

Thanks, and apologies if this is a redundant post.

Jeremy

Hi there
Great to hear you got a replacement under warranty but a 50mile range with a new battery (Edit: initial range 5years ago, but what was it after battery replacement?) seems a bit on the low side to start with but your current 18miles certainly isn’t right (what average speed would you be doing?)
I don’t think your range issue is related to regenerative braking, but just for peace of mind: does the Amp needle on the dash go down into the blue ‘charging’ section when you hit the brakes and back up if you ease off or come to a standstill?

I assume given the short range you routinely go below 2 bars and then fully charge back up to 16? Do you ever get the red HV warning or tortoise symbol while driving?

In order to have an idea where to start you need to borrow (or buy) an OBD2 dongle and use diagnostic sw to look at your battery stats as the range calculation is (mainly) determined by your weakest cell.

A bit concerned that the dealer couldn’t do anything, did they offer to do a battery calibration to recalculate the current capacity??

Hi, thanks for the reply!

Answers below:

I tend to drive it just for local errands on surface streets. So, up to 50mph for a mile or two, but mostly 45mph or less. Most trips are < 4 miles each way.

It does go into the blue area when I apply the brakes, and it does go back up into the green area when I let up.

I've never gotten the red HV or turtle warning light.

I try to keep it above 2 bars, and less than 14 bars (approx. keeping it between 20% and 80%). I almost never go below 2 bars, but do occasionally do a full charge.

I have an ODB2 reader, but it only allows me to read codes and clear them. Do I need something specific to look at the battery cells like you suggest?

The only think the dealership had to say was "Make sure and drive it more. Charge it all the way up, then drive it till it's on zero. Do that a lot."

Thanks!

From the “advice” you got from the dealership I would not be surprised if they never “told” the car that a new battery was fitted so the BMS will update the capacity gradually, but it will take forever as you only ever use it for short journeys.

Can you by any chance remember what new battery’s initial RR (fully charged) was?

See below for ideas about diagnostic sw:
https://myimiev.com/forum/viewtopic.php?p=45287#p45287

Yeah, they were an uninspiring bunch. By RR do you mean Range? It said 36 when I picked it up at the dealership.

I'll check out the other posts for ODB2/SW info.

Thanks!

Sorry, follow-up question: Is there a way for me to tell the car there's a new battery/reset the computer (as it were)?

Thanks!

jeremybbarnes said:

Sorry, follow-up question: Is there a way for me to tell the car there's a new battery/reset the computer (as it were)?

Thanks!

Click to expand...

I’m afraid not, the dealer should have done that using their MUT3 diagnostic tool. Easiest would be to go back and demand they run a proper battery calibration procedure (takes about a day to complete)

Second best option is to do it yourself, to my knowledge there is only one 3rd party app (HobDrive) that has this function implemented, although it’s still beta, some members have used it successfully.

Hi, so sorry to be so needy here, but...

I got a dongle and hooked it up. I can't figure out how to do anything with HobDrive, but I got ODBZero to work, and it gives a lot of information on the battery cells. What am I looking for?

Thanks!

HobDrive is a generic app that needs an IMieV profile set up to unlock the EV functionality, while ODBZero is specifically made for IMiev (and clones) and works ‘out of the box’

There are various discussions on how to use it in this forum but to start you want to compare the cell voltages at different charge levels with/without load and look for any outliers.

Best to post screenshots of what you find.

Haven’t used OBDZero in a while but had a quick look earlier; in the OBD tab under battery, what values do you get for Voltage, SoC, Capacity and SoH? Cells min/max voltages and temperatures are also good indicators of potential problems…

MickeyS70 said:

Haven’t used OBDZero in a while but had a quick look earlier; in the OBD tab under battery, what values do you get for Voltage, SoC, Capacity and SoH? Cells min/max voltages and temperatures are also good indicators of potential problems…

Click to expand...

OBDZero saves data in semicolon separated text files in the OBDZero folder on your device. These files can be opened in Notepad and Excel. There are instructions for this in the user manual: https://obdzero.dk/wp-content/uploads/2022/08/OBDZeroUserManual38.pdf

If you can download the files to your computer but run into problems reading them then send them to me via e.g. google drive and I will do some analysis. You can send a link to your data in a private message.

Cheers
David

OK, thanks for all of the help! I feel like I'm making progress on HobDrive. I'm still working on getting the data files, but here are some screen shots of the battery information...

https://1drv.ms/u/s!Ao6IRjyqjS4-xagFXmWr1xzf6UcyQg?e=uV2RwW

These are both from when the car showed 14 bars and 18 miles of range.

Thanks!

jeremybbarnes said:

These are both from when the car showed 14 bars and 18 miles of range.

Click to expand...

Ok, no surprise here, cell’s are well balanced as you would expect from a new battery. It all points to the BMS operating with the old capacity value; could you post the second set of parameters (SoC, Capacity, SoH) I mentioned?

Sorry for the delay, here are the other screen shots.

https://1drv.ms/u/s!Ao6IRjyqjS4-xagFXmWr1xzf6UcyQg?e=OMqEBi


Also, I looked around on the forum, but I couldn't find anything about other folks using HobDrive to reset the battery/recalibrate. Can anyone point me in that direction?

Thanks!!!!!

It’s pretty obvious that something went wrong during battery replacement (diplomatic speak) but at the end of the day its Mitsu’s responsibility to rectify this with their MUT3 tool. It may be worth to present the dealer with your findings and point them in the right direction as there is very little information on the DIY procedure

The only reference I found was on a different forum:

https://www.speakev.com/threads/peugeot-ion-battery-state.167962/

“Grab Hobdrive and install the latest beta. There's a section which will allow you to run a battery calibration routine (this will flatten the battery down as far as it can using the heater, then fully charge the thing. Wind your windows down, set heating/fan to max and plug the granny charger in before you start)”

MickeyS70 said:

It’s pretty obvious that something went wrong during battery replacement (diplomatic speak) but at the end of the day its Mitsu’s responsibility to rectify this with their MUT3 tool. It may be worth to present the dealer with your findings and point them in the right direction as there is very little information on the DIY procedure

Click to expand...

This is the right way to go. On the German forum:

https://www.goingelectric.de/forum/viewtopic.php?f=222&t=23324&start=330

There are 3 reports of battery replacement (Batterietausch). In each case the new battery had more than 42Ah capacity. Not the 17 Ah shown in the screenshot.

Yeah, that's what I was afraid of. I'll try to get the dealership to do something.

Thank you all for your help!