Phev Insight

[retepsnikrep]

I can't confirm that was the pack voltage it reached, only that one cell was pushed over Vmax and triggered the alarm. The 192.5v is the pack theoretical abs max voltage if all 50 cells are charged to 3.85v.

I was watching the highest cell voltage on BMS and forced charge was pushing one of the cells over the VMax 3.85v.

The pack V was probably substantially lower and one cell was out of balance so went over V as it was fully charged.

One full charged at 3.85v but others could have all been around 3.2v which gives a pack V of about 165v

From other users experience these Li-fepo4 cells generally remain at 3.2v over most of the charge curve but then V rises rapidly at the end.

I need to burn off some charge and then try it

I need to clag a few more meters on the pack and watch things closely with the people visiting today that may be a bit easier.

It's all very early days of course

I'll add a dvmm to battery terminals today and compare readings from BMS, also need to add my current clamp meter to check BMS current sensor accuracy.

Let's not jump to any conclusions at this stage

[Insightful Trekker]

Originally Posted by IamIan

I doubt the Insight ever charges to 100% SoC ... and unless it does it would never see the voltage blip at the end of charging.... even if it did... it is only ~3mV... that is a tiny blip... and each cell would probably not hit that point at the same time.

Good point Ian

Originally Posted by Mike Dabrowski 2000

I guess my assumptions about max voltage causing the charge termination after a reset could be wrong?

Remember Mike, Peter's changed battery chemistry. So given the voltage differences you and he are now finding is seems that voltage is _not_ a BCM logic function afterall...?

(Edit: Nevermind, See Peter's subsequent post immediately below)

[Mike Dabrowski 2000]

I see, it was the individual cell voltage that hit max. As you say, this is all very early to make any conclusions.Wish I was there.
Keep us posted on your findings, and good luck.

[retepsnikrep]

Now burning off some charge with a 0.5A dummy load. Hope to try and start it tomorrow when I have taken 10ah or so out of cells.

Also found an error in the software, but still some glitches remain as onboard charger is not responding correctly yet

Peter

[IamIan]

[retepsnikrep]

Eta for test engine start and forced recharge bcm recalibration is 10:00 GMT

I will have drained 10ah out by then down to 30ah, this should give sufficient headroom for the initial charge

Corrected a stupid error in Master Software which was source of the failure to control charger correctly Debugging don't you love it

MIght video it for posterity

[retepsnikrep]

Started OK and took the initial forced charge fine, oem Batt gauge is now showing about 1/3charge, no untoward faults and I actually drove it down the road for a couple of 100yards, standard assist and regen seem to be working fine.

My BMS is all over place at moment though as strangely one of the most inaccessible slave boards is false triggering, dumping data on the Master bus, setting off the following 5 cells as well and upseting the Master. I now have the batteries back out on bench and am making another Slave board as I suspect a dry joint or bad pic, interference, oddly it has been working fine on bench and in car so long as IMA is disabled/off. MIght add some local screening as well.

Back into garage now!

[retepsnikrep]

Well back indoors now bloody cold outside in garage. I'm quite happy at the minute with the way the OEM BCM has accepted the new cells. I've deliberately triggered a few faults by disconnecting oem temp sensors etc and they flag up with IMA/check engine lights as expected. Glad I've got a Scangauge!

BMS slightly more stable now the false triggering slave has been replaced, still not right or useable at the moment. Def interference or power supply fluctuations getting into Master causing it to reset etc. I suspect the Master data bus

A few things I intend trying. So got to take battery case out of car again to do a few tweaks.

1) Add some probe points to Master bus, I made the wiring so tidy I can't get access to the master bus without pulling it out of car!

2) Try running Master on a completely independent exterior power supply to see if that corrects problem, if it does it means problem is coming in over 12v car aux supply, may then add a 12v-12v miniature dc converter to isolate Master supply from car.

3) Drill hole in Zivan charger case to get access to voltage pot, should have done this before!! Again I've got to remove the unit to get access at present.

4) Get my scope on the Master bus and power supply, pic inputs to see what's happening.

5) Reduce Master bus serial data speed to 1200baud to see if that helps to make data more error resistant. I'll try this last.

So not working properly yet but I'm not slashing my wrists either, just got some problems to overcome.

[Mike Dabrowski 2000]

Peter I understand what you are going through. The Insight IMA produces a lot of HF spike and noise, and they seem to work their way into many other signals. This is why I needed opto isolation on the TPS,MAP, and current signals.
Good progress so far, and your list of things to try should show you the solution.
Good hunting.

[retepsnikrep]

Well

Isolated supply improved things quite a bit, and incredibly when you see the noise still present on the Master bus it almost runs without errors!!

So problem is as Mike surmised horrible noise on Master Bus. This noise is on the paralleled opto isolated side of the digital slaves Master Bus which weaves it's way round the packs before exiting to the Master board input. I need some sort of filtering/preconditioning now to sort this, any ideas more than welcome.

http://www.solarvan.co.uk/bms/Noise1912.jpg

Hidden amongst that noise you can see a couple of bits of serial data being transmitted

My initial thoughts are another layer of opto isolation

I intend changing the bus pull down resistor from 10k to 1k to see if that helps.

I also thought about a 4.7v zener diode to cut off the high voltage spikes as they could damage the Master pic or at least cause it to lock up. It had been reseting itself at will due to this horrible noise. Over to the experts out there.

Appears the Insight is even more of a noise nightmare than I thought!

The Digital slaves all seem to be working fine though even directly exposed to that noise

Some pics.

http://www.solarvan.co.uk/bms/Install1912.jpg All plugged in but not fixed finally.

http://www.solarvan.co.uk/bms/Dash1912.jpg

Dash show batteries accepted by BCM and forced charge stopped after a couple of minutes, soc now 4 bars, bat voltage 167v, interestingly I measured the voltage of the nimh one I removed which had been charged to within one bar of top and it's voltage was about 158v. No IMA errors.

http://www.solarvan.co.uk/bms/Display1912.jpg