Phev Insight

[JimIsbell]

T=RC is the formula. In this case T= .00005 This noise is an easy one to get rid of. Its 10 times the frequency of the data. I would use a 1K resistor and a 50pf capacitor. Actually better would be to use a 10K pot wired as a variable resistor so you can adjust it to best filter out the noise without hurting the data.

[retepsnikrep]

Thanks for the values above.

I've knocked up a simple analogue Master circuit to provide visual and audible Over - Under Voltage indication and charger control. I intend to install this this week to allow me to actually test cells in situ and see how it reacts with the Insight BCM in more depth. I'll add a simple 0-200v voltmeter as well as a simple fuel gauge

http://www.solarvan.co.uk/bms/AnalogueMaster271208.jpg

While I'm doing this testing I shall move and adapt the Digital Master with some re-wiring, filtering.

I'm moving it out out of the IPU compartment which is an rf nightmare, and am going to put it behind the now redundant battery cooling air vent behind the drivers seat with some rear aluminum screening.

I can then get at it by simply prising out vent grille, at the moment I have to go into rear compartment and disconnect far too much stuff

As it's out of the rf area it should be better for it as well.

I have found it is critical to ensure cells/pack can accept the first forced charge and are not full on first install. I would say charged to about 75% max is enough. The forced charge rate was about 6A for about 3-4 minutes until BCM had enough data to give an initial SOC.

The IMA then operated normally.

When I re-installed the nimh pack it did the initial soc forced charge, and then did a positive recal after that within about five miles, increasing soc to one bar from top. (That had been the indicated soc of the pack when I took it out)

I didn't run the lithium pack past the forced charge stage during my initial testing, so it will be interesting to see if it also does a positive recal as well when I put it back in, as it had a higher open circuit voltage than the nimh pack.

Hope to do this work within next week as I have a few days off.

[retepsnikrep]

Reprogrammed slaves for temp Analog mode

Still tinkering, just finished temp Analog Master, and now fiddling with meter and led/switches which have to fit into the centre console cubby hole at front alongside MIMA display. It's the asthetic things that take the time Getting it looking reasonable is sometimes the greater challenge.

I'm leaving the screen and digital master gubbins/cabling installed as I can work on that then alongside the up and runing analog temp system hopefully in few days. Now hoping to get it installed/running tomorrow minus voltmeter which is on order.

The analog Master gives reduced functionality, but still covers the vitals.

Over Cell V audible Alarm when ignition on. (For driving regen)

Over Cell V visual Alarm at all times.

Over Cell V isolated charger cutback. (For controlling mains charger)

Under Cell V audible Alarm at all times.

Under Cell V audible Alarm at all times.

Temp is covered by normal IMA temp sensors when running and I have a simple digital gauge I may rig up as a temp measure.

Digital 0-199.9V meter also fitted running all time.

Digital Slaves (Analog mode) Test button propagates a low V alarm through the 50 slaves and activates low V alarm. If any of the 50 Slaves is off line/stuck/locked up etc signal won't make it to the last slave and therefore no Alarm will sound. Just press the button when you get in car to check they are on line, takes approx 500ms to respond.

I found some nice accesible power at the BCM plug on top of the battery pack. I need ground, +12V live at all times & +12V ignition switched. The analog Master is pretty well isolated but I have added some filtering on this supply to hopefully prevent any problems.

[retepsnikrep]

It's In and working in analog mode

Been for a 25 mile trip just to check it out. BCM forced charge for a bit then gave an initial soc and then continued charging normally no positive recal. No IMA errors. Charge now at about 3/4 75% and I have just topped it off with the mains charger working under BMS control, seems fine and once one cell goto to Max V it held voltage steady and current started falling away. Zivan charger now adjusted to about 176V for the CV phase

Be interesting to see what happens next time I start car and if it notices the extra charge I put in when it was off?

(Greg) Seems the simple on/off for the charger opto works fine with the Zivan.

Just drove it normally for first test, no obvious issues. No over or under V alarms even under quite hard regen. Cells are very cold it's been about 0C all day and Insight BCM is doing it's normal NImh limited 50% assist. Seems normal.

Off to get an Indian Takeaway now as a treat/reward, I'll see what mpg I can manage on this 10 mile round trip.

Need to get some experience now with how it all interacts. Some cosmetic bits to do in boot as the cargo area is now a bit shallower so I need to cut the liner down 4 inches in height so it still fits. Need to finish bolting in cell trays from underneath as well and install pack voltmeter which should arrive in AM.

Some Pics

www.solarvan.co.uk/bms/Rear010109.jpg
www.solarvan.co.uk/bms/OnCharge010109.jpg
www.solarvan.co.uk/bms/IpuEntry010109.jpg
www.solarvan.co.uk/bms/Ipu010109.jpg
www.solarvan.co.uk/bms/Dash010109.jpg

Had to cut a small section of IPU cover to get clearance for cables.

Voltmeter will be going to right of leds in the blank area.

[JimIsbell]

Bravo!!!

[Mike Dabrowski 2000]

Congratulations Peter, what a nice way to start a new year.

[IamIan]

[retepsnikrep]

Didn't go for a further test in the end today.

Secured batteries instead as a safety priority. They are bolted through side of wheel well into captive nuts on the two battery blocks/trays 6x6mm per tray. I'm pretty confident they would remian in situ now in the event of a roll over, I don't want to test it though

Charger finished cycle and turned itself off, some balancing taking place as I could see the cells turning the loads on/off. Charger was not voltage limited by BMS this time As cells get more into balance I may tweek the finishing voltage up a bit, I think I have it to low now but better safe than sorry during this testing phase. 176v divided by 50 cells averages out at 3.52v each at present.

Edit

This was the final version of my Analog Master schematic. Good job I made the Slaves fairly versatile

http://www.solarvan.co.uk/bms/AnalogueMaster010109.jpg

Edit

Interestingly I can still see the horrible noise on the Master Bus (Doesn't effect analog operation) but it will help when I start the filtering process after I have relocated the Digital Master. I will be re-wiring the Slaves with some nice twisted pair screened cable for the Master Bus and all the other links inside the IPU compartment. I've learnt a lot so far including how not to wire the pack for use in a very nosiy environment Didn't Edison say he found 999 ways how not to make a light bulb before he found how to do it

[Roger Crier]

I have been religiously tracking your progress on the various forums, but have declined to chip in with much help recently as I am unable to provide any! Frequency calculations, with their massive numbers and logarithms and stuff like that was the point my brain exploded all those years ago at college

Looking at the whole project, now it has got to the final sorting phase, you should soon be able to switch from "sleepless nights" mode to the realisation that you have designed and built something quite remarkable. You especially, but also all the other willing contributors who helped along the way, should now take a bow.

[retepsnikrep]

Thanks for that Roger I do fell pretty pleased at the minute!

First Findings

45 Mile trip today 112mpg (UK) compared to my normal for this time of year abour 93mpg. Lot's to learn.

First thing I learnt was MIMA is vital, if you can't turn off forced charge and command extra power then it's a no go IMO. Well done MIke

OK How did BCM react? Well after topping it off last night via mains charger, it did not do a positive recal this morning. To be fair it was showing about 75% on dash gauge anyway. I started the journey with cells pretty cold at about 2C I had no autostop for entire journey due to cold air temp. Engine took quite a bit longer to warm up as the power was being offset by extra assist I altered my driving style from my normal peg instant FCD at 100mpg to peg it at 125mpg.

Today I used as much assist as was reqd to maintain 125mpg at 40-45mph over my normal commute, traffic in town at end of journey was horrible, so that brought it down to the 112mpg. Initially charge fell away on gauge at about the rate I would expect for normal IMA use at this level, and it was def counting ah IMO until it got to three bars. There it sat for the rest of the journey It appeared to be waiting for a nimh cell to go low which would have then triggered the gauge to fall to zero and stop assist etc. But as the cells didn't go low it just allowed assist ad infinitum. It was trying to force charge but that was disabled. It did not trigger an error, but just sat at three bars. Assist seemed to be limited to about 50% which was not a bad thing and may have been due to the battery temp or the indicated soc. Anyway it prevented me from abusing my new cells with some 100A assist

Battery temp at end of test was about 10C but car had been heated during hour long journey as well. No hot spots in pack when checked with infra red thermometer. Battery resting voltage was 165V at end of trip. 165/50 = 3.3v which is about the nominal voltage for these li-fepo4 cells. I don't know how many ah I used, but car is now on charge and I will know the kwh consumed from the mains in a couple of hours.

For the trip I disabled regen unless commanded with joystick, so it never charged except when braking/slowing down. I used manual assist and regen for this first test, sometimes when on a decent straight I put on one led of assist and then clicked the joystick to maintain it.

If one led fully lit is about 25A of assist that seems reasonable for the cells, which should be able to supply that load for about 90 minutes.

Also no High or Low Cell voltage alarms during trip even under hard 50A regen and BMS seems to be working fine

Sadly I'm back at work tomorrow and voltmeter hasn't arrived yet so that will have to wait.