Battery pack change plans

[kiev]

Have you tried to measure if there is any continuity, resistance, diode drops between the control sockets and the ground socket in the handle of the charging cable--might give some clues?

 

[alviseven]

Have you tried to measure if there is any continuity, resistance, diode drops between the control sockets and the ground socket in the handle of the charging cable--might give some clues?

no because it worked on the original charger to the car - one which needed a black box and was quite happy working from the house charger - this current one is from the red CMU car with the straight 13amp plug - works beautifully only on the charge cable which came with the donor car.
Came to the conclusion that the charger must be looking for something different and whether it could be altered to match the original - if not plan to put the original back on knowing that I have a spare that works but it would be nice to be able to alter this one to match the other which would be even better. Double win!

 

[MickeyS70]

current one is from the red CMU car with the straight 13amp plug - works beautifully only on the charge cable which came with the donor car.

We’re pretty sure that the 2015 red CMU OBC HW is capable to charge with or without ‘brick’. This would mean the ‘mode’ it’s in is either set in the OBC’s firmware or as @kiev suggested via additional (or different) components inside the Type 1 plug.

The fact that the car doesn’t even recognise a ‘brick type’ EVSE plugged in, suggests the latter.
If possible, open up the brick/no brick type 1 plugs and compare the innards, otherwise measuring resistance as @kiev mentioned might give a clue.

If there are no differences, the programming is probably done via firmware in which case you’re better off swapping back the original OBC if you want to charge using a ‘proper’ EVSE.

 

[alviseven]

Went to the Grampian Transport museum whilst on holiday last week and was rather surprised to be met at the entrance by a silver 12 plate Imiev on display with a couple of other electric cars as part of their display. Go 400 miles plus north in a 76 year old car to be met by an imiev in a museum!

back to the CMU boards tomorrow as the repaired on is back.

 

[alviseven]

Got the original charger back on the car before I change CMU09 back to the repaired one

Nice to report that the black box elements fire up and the car is charging again from this unit - so it was the CMU09 fault that was scotching the whole elements originally as I hoped.
Pleased as it shows I have a working spare charger even if it only works from 13amp plug

Now to change this repaired CMU board...

 

[alviseven]

The good news is that I seem to have a fully working decent car again which charges from the house charger and off the black box lead again.
Replaced the repaired CMU 09 green board into the pack and this gives no DTC issues
Did replace all the outer hold down bolts on the outer plastic hood with stainless steel ones just on case I need them open again.
So my 700GDP gamble has paid off it seems. Now have a working car which seems to have a range of about 50 miles and a pile of spares to boot including a tested working charger.
Learnt a huge amount even if I have done little else for the last four weeks. Feel like I know more about these delightful little cars now.

 

[MickeyS70]

Now have a working car which seems to have a range of about 50 miles…

Well done!

BTW the car doesn’t ‘know’ you changed the cells and therefore still calculates RR with the old pack’s capacity.

The BMU will update the value over time after a calibration charge but if you want a quick fix, HobDrive can re-calculate and set the new the pack capacity in one go.

 

[alviseven]

Yes it was mentioned and I did look on hobdrive but could not see it or dare use the recalibration one I did find

Presume I can not do too much damage

 

[MickeyS70]

Presume I can not do too much damage

None, but in order for this to work correctly, the cells need to be deep discharged (around 3V, IIRC), then activate the function and charge to 100% on a granny in one go and let balancing complete.

 

[alviseven]

I have driven the car to flashing two bars and still hobdrive is reporting that the battery is 60% charged and the cell voltages are about 3.7volts I have according to the dash only 5 miles left and have done 32 since I charged it - read full left overnight and then read three quarters full.

Am I really going to drive it till it stops and get the voltage down to 3V or am I low enough to start a calibration charge?

When I start this calibration charge do I need to leave the phone connected to the car? AND I assume if so it needs to be in the car to talk to the bluetooth thing it connects with?

 

[CeeJay09]

run the heater in the driveway until 3v a cell

 

[MickeyS70]

I have driven the car to flashing two bars and still hobdrive is reporting that the battery is 60% charged and the cell voltages are about 3.7volts

HobDrive calculates the SoC based on cell voltage, the BMU is using coulomb counting but takes the old battery capacity as a baseline hence the need to recalculate it

I have according to the dash only 5 miles left and have done 32 since I charged it - read full left overnight and then read three quarters full.

Did it change SoC without driving?

Am I really going to drive it till it stops and get the voltage down to 3V or am I low enough to start a calibration charge?

Drive until tortoise then use heater/AC/blower etc as @CeeJay09 suggested. What might also help is to disconnect the 12V aux briefly with flashing RR to force the BMU to do a cell based SoC calculation.

When I start this calibration charge do I need to leave the phone connected to the car? AND I assume if so it needs to be in the car to talk to the bluetooth thing it connects with?

Never actually done this with HobDrive, but OBDZero requires the app to be active and connected to the dongle at all times (disable screen lock) during calibration.

On the other hand Diagbox) tells you to disconnect the diagnostic tool once charging has commenced and to reconnect when full.

I would go with your assumptions unless someone here on this forum has first hand experience to the contrary

 

[alviseven]

Don't know if this depresses me or not...
Sat with heater on full blast for probably half hour or more. The two remaining bars did disappear but hibdrive never reported voltages lower than 3.785v at one point I switched off and when switched back on range gone from.3 back up to five and had two bars on dial again.

Tried both obd and hobdrive to get the state of charge but the figures I seem to get were all still 60%

Could not get it any lower than 3.7xx to show and could not get it to measure SoC on OBD

Eventually I started getting cmu 09 errors again which would cancel but clearly either this board is not 100% or car not happy with it. Seems to be cell F which gives the issue drops to 0.7 or 1.275 then jumps back to the pack voltage.

Put on granny charge and tried to set the charge smoothing but it said there was an error. Charge also dropped out but now has two bars and rising and not dropped out again now.

Think I shall gave to try not to let car get too flat and let the granny charger and time sort the car whilst I look for a green cmu 09 replacement

It does seem to give me a better mileage per charge and far less worried its going to suddenly conk on me even with the less than 70 miles we have done since the pack change.

Stick to the idea that the car works charges, and dies about 35 miles range at the moment and see...
Far better than a car that would not charge, had a variable range pot luck from 3 to about 25 miles and was stressful to drive.

 

[CeeJay09]

you do not need to get a number 9 specifically btw, you can use any green CMU board and get a shop to renumber them accordingly

 

[alviseven]

Shop as is garage or specifically a dealership or just someone with the stuff? ON or OFF the car? Fitted or loose? Did know that they could be renumbered but still easier if I can get the right numbered one!

Still need to find a green CMU board however.

 

[MickeyS70]

Shop as is garage or specifically a dealership or just someone with the stuff? ON or OFF the car? Fitted or loose? Did know that they could be renumbered but still easier if I can get the right numbered one!

Still need to find a green CMU board however.

You can read out the ID chip information of one CMU and copy it onto another, swapping the chip itself also works.

If you have access to a dealer diagnostic tool you can re-number a complete pack in situ. If not, you could tow the car to a dealer and pay £££ to get it sorted.

 

[CeeJay09]

I did not realize the boards had ID numbers when I removed mine and they went back in an unknown order, I did a lot of reasearch and found that they can be renumbered. I towed my imiev complete to the shop with a special scan tool (ill find the name) and they plugged it in and reset the numbers for a box of beer it took 5minutes

 

[CeeJay09]

I have a box of green CMUs (unknown numbers) here in Perth WA, the shop I used to set the number up may have a number 09 on hand if you want me to ask.

 

[alviseven]

Update
Car still working and git over 40 mile on last charge which is massive improvement on previous battery
Not had any cmu issues till car gets down to about last four bars on meter then cmu09 starts to fault.

Failed to get OBC to pick up charge tonight from 3 bars left not having it at all.

Went to chademo which worked no issue.

Came home and OBC kicked in no issues and charging fine.

With battery full chademo I was about 5 bars from full and range of 37 but now on obc charging and will see.

In use have a clunk and jerk in transmission again almost like a lose connection but still not giving me any DTc codes on hobdrive which it consistently gives me charge and cmu09 faults when low. Get no battery fault until the car charge is relatively low.

However it is manageable and still enjoy driving the car.

STILL looking for a green Cmu 09 board.

Think I shall have to put my red cmu09 board back in pack since this gave me far less issues and it's a doddle to do now.

 

[alviseven]

Further strange behaviour and a NEW code today

Charge put on granny charge last night and got over 50 miles showing on the range - first time it has done that for years.

Took two miles up the road and when returned battery down to about 3/4 full
Took to work but within about 2 mile from off tortise on and returned but managed to clear DTC and then parked up and tortise off.

Put back on charge again tonight and had this strange sensation.
watched the granny charger drop out quite quickly but with no fault on the charger lit and no battery light on the dash.
Plugged back in and repeat but then realised that the charge meter was increasing
It was about at the start about 2 bars below mid point and progressively from about 5 attachment of the granny charger went up in bars of 2 or 3 to one short of full and now reading 46 miles range.
Just before I connected the charger on this surreal five minutes I checked hobdrive and has a new DTC which read

P1A4B voltage of each battery cell abnormal

No idea what this is but perhaps it explains why the battery meter is playing games
I can only assume that perhaps the BMS is confused still trying to work out why the "new" batteries are stronger than the ones it is "used" to and this is throwing it into confusion and making it think that we have used more or less power than expected? The car still drives fine and will granny charge certainly from about 4 or 5 bars empty upwards baring the issue above.

At least this time I do not have the dreaded CMU09 fault code so perhaps this is progress or is this a more serious code?
Good news it got me to work and back yesterday with zero issues and I was just starting to celebrate - not managed this for nearly six months now. Now wonder if I was celebrating too early.