New owner, old i-Miev, CHAdeMO issues!

Mitsubishi EV Interest Group
Post Reply
MattT
Noobie
Posts: 2
Joined: Thu, 01 Jun 2017, 18:46
Real Name: Matt
Location: Canberra

New owner, old i-Miev, CHAdeMO issues!

Post by MattT » Tue, 06 Jun 2017, 02:33

Hi all

I purchased a 2010 i-MiEV abut a month ago from a colleague who has upgraded to a Tesla. It's in good physical nick. The battery has seen better days (more below) but it's more than enough to do my 35km round trip to the office plus some evening errands. At $14k with ~53k on the clock it was probably more than I wanted to pay, but I knew the owner, wasn't relishing wandering around Canberra car yards in late autumn, and it came with new tyres, a full service history, and all but the latest bit of recall work done.

According to the paperwork in Feb 2015 (having done about 19k) the cells were all showing 4.055v and 'actual capacity' was 86%. In August 2016 the cells were at 4.010v with five at 4.005, with capacity at 35.8Ah. I've just hooked it up to EVBatMon and max cell voltage seemed to be 3.92v, minimum 3.88v, capacity 34.6Ah, battery condition 72.08%. (So much for Mitsubishi's claims of no appreciable deterioration in ten years.)

I just charge it overnight using 240v AC through a 15A to 10A converter. I haven't really needed to use Canberra's public charger network but over the last week thought I'd give it a go, as once per week I may need to do a round trip of 72km. The RR reckons I'd get 80km from a full charge, and I did once do 65km with 16km to spare, but it's too close for comfort. A 15 minute CHAdeMO charge at lunch time seemed like the solution.

I used the 'rapid' CHAdeMO charger in Civic, Canberra. I started at 25% charge so figured ten mins tops to get to 80%. Nope - 25 minutes to get to 57%. Tried a second charger in Tuggeranong on the weekend. Starting with 23% / 3 bars, charge progress was:

2 mins - 28% - 0.5 kWh
8 mins - 37% - 1.8 kWh - 4 bars
10 mins - 40% - 2.2 kWh - 5 bars
12 mins - 42% - 2.6 kWh - 6 bars
14 mins - 44% - 2.8 kWh - 6 bars
15 mins - 45% - 2.9kWh - 7 bars (just) - predicated range 39km

Any ideas what the prob might be? I've only just installed EVBatMon so don't know if any of its widgets can give me more useful info.

Cheers
Matt
MY2010 I-MiEV | Canberra

User avatar
coulomb
Site Admin
Posts: 3324
Joined: Thu, 22 Jan 2009, 20:32
Real Name: Mike Van Emmerik
Location: Brisbane
Contact:

New owner, old i-Miev, CHAdeMO issues!

Post by coulomb » Tue, 06 Jun 2017, 03:27

MattT wrote: I've just hooked it up to EVBatMon and max cell voltage seemed to be 3.92v, minimum 3.88v, capacity 34.6Ah, battery condition 72.08%. (So much for Mitsubishi's claims of no appreciable deterioration in ten years.)
So here battery condition seems to be the percentage of nominal Ah capacity; 34.6 / 48 *100% = 72.08%.
Starting with 23% / 3 bars, charge progress was:
...
15 mins - 45% - 2.9kWh
So that's 2.9 kWh in 0.75 hours, or 2.9/0.75 = 3.9 kW average. Faster than slow charging, but nothing like what CHAdeMO is capable of.
Any ideas what the prob might be?

My guess is that you have one or two weak cells, so the car's BMS has to restrict the charge rate to prevent those weak cells from going over-voltage. Your EVBatMon should be able to find them.
Learning how to patch and repair PIP-4048 inverter-chargers and Elcon chargers.

g4qber
Senior Member
Posts: 1661
Joined: Sat, 31 Jul 2010, 06:27
Real Name: Joseph
Location: Perth
Contact:

New owner, old i-Miev, CHAdeMO issues!

Post by g4qber » Tue, 06 Jun 2017, 13:46

Also may need to drop below 2 bars and fully charge to recalibrate the battery meter
My 2011 with 2010 cells has gone from 94% PMC to 74% since march '17
:roll: 2011 i-MiEV - 147 kms August 2018

MattT
Noobie
Posts: 2
Joined: Thu, 01 Jun 2017, 18:46
Real Name: Matt
Location: Canberra

New owner, old i-Miev, CHAdeMO issues!

Post by MattT » Tue, 13 Jun 2017, 19:04

EDIT: AAAAAAND I'm an idiot. I'm pretty sure I ran this morning's test in emulation mode. I thought those figures looked familiar! Image

EDIT EDIT: Yep, emulation mode. Just checked my stats again and they haven't actually changed at all - still 72.08%.

-----------------

I finally got around to running the i-MiEV down to less than 2 bars (1 bar flashing, 7km range), then charged it at 10A / 240V overnight. This morning EVBatMon was showing 75.62% battery condition, 36.3 Ah capacity, cell volt range 4.02v - 4.01v. So not a huge difference, but better than the August 2016 results, and I'll happily take the extra 3.54% / 1.7 Ah! Thanks for the tip.

I'll see if I can get it to a CHAdeMO charger this week to see if it's working now. I noticed that last week EVBatMon was reporting a few different high cells and low cells, now it's just one of each.

One possible issue: EVBatMon has my SOC Real (state of charge?) wandering all over the place. It looks like a cardiogram, with peaks at 70%, troughs at 20%, and a midway blip at 40%. Is it supposed to do that?
Last edited by MattT on Tue, 13 Jun 2017, 10:03, edited 1 time in total.
MY2010 I-MiEV | Canberra

Post Reply