Phev Insight

[retepsnikrep]

Too much to do, not enough time

Also wasting time going on pointless test drives

[Insightful Trekker]

Originally Posted by retepsnikrep

Also wasting time going on pointless test drives

Unless you can combine the trips like your earlier gallon of fuel for a pint of ale trade-off.

[retepsnikrep]

Originally Posted by Insightful Trekker

Unless you can combine the trips like your earlier gallon of fuel for a pint of ale trade-off.

Sadly that trip is not until Monday 19th Jan

Charge now finished used 3.7kwh today

[The Citrus Smoothie]

Peter, I have been watching this thread with growing admiration for your hard work and innovation. Congratulations on a great job. I can imagine what MPG figures a long trip in the summer will bring. I have only been quiet because of a complete lack of mechanical & electrical skills on my part and so unable to help. The work that you and others have been able to achieve makes me that much more confident in buying another Insight when a half decent one becomes available. Best Wishes for 2009.

[IamIan]

I guess one of the big things ... that we still don't know is how the BCM will react to a unchanging static voltage when it sees Amps coming in or going out?

If the BCM throws error codes than the whole idea is a bust.

If the BCM takes the flat unchanging voltage and happily gives no error codes... than this is at least an option... and then further work would determine the actual voltage set point... 180V might be fine... but you might only need ~160V... until we know... we don't know.

[retepsnikrep]

The reason I am thinking of fooling it with a high voltage (175-180V) is to stop it ever doing forced charge and to always give you a high soc with a very quick positive recal capability perhaps. Extra egar to assist as well would be great, and may mean a limited Li-ion conversion is possible without MIMA.

I'm getting a bit more concerned with the BCM three bar drop off point as well, it was very cold again to be fair today -3.6C so batteries very chilly and with a big thermal mass they don't warm up quickly Had a couple of times on my 40 mile trip when soc fell below 3 bars today forcing me to charge to 4 bars again. It does not appear very consistent at the minute No errors though and still doing 108mpg in -3 temps on another very hilly route

I think I'll' measure the bcm taps current next time I have IPU open and then perhaps order a 12v - 0-200v dc-dc converter and build up a pd to have a go.

Anyone care to somment on resistor values for the pd. Lets say the current drawn is <5ma as a starting point.

As we don't know how bcm measures the voltage, it may be polling those sense inputs it may be better to use the 10 x 18v dc-dc converters as they can adapt better to a change in current drawn at any one point. If the curent drawn if any, is not consistent at the taps then with a pd it will throw it all off will it not?

[benjamin]

I haven't bothered to sticky this great thread because it's been at the top for a while... but will do so now.

[IamIan]

Eagerly looking forward to the false steady state voltage under load test to see if it pulls an error code.

You already have altered temperature sensor data ... We briefly touched on altering the current sensor... now we are exploring altering the voltage sensors... Good thing you already have your own BMS ... because at this rate the BCM may not have any real battery sensor data going to it after much longer. It's ok though ... we just want it to do its communication thing with the MDM to give us the assist and regen when we want it / how much we want it.... and the IMA stabilizing too I guess... and your dash display will tell you about the status of your battery more so than the stock SoC bars ever did.

[retepsnikrep]

Originally Posted by IamIan

You already have altered temperature sensor data ... We briefly touched on altering the current sensor... now we are exploring altering the voltage sensors... Good thing you already have your own BMS

I retained all the original oem temp sensors inc some of the ptc it/they are installed in my two battery blocks. I added two extra I2C ones for my BMS.

I have not changed the current sensor although we have talked about it.

Again we are talking about it but not done it yet.

Yes a BMS is critical but you can combine one with basic over/under V signal capabilities with the standard bcm and that works as we have seen.

[retepsnikrep]

Warmer Weather

Positive recal within half a mile of each charge. I think I may have the charger voltage about right 176v now. After charger finishes it's cycle pack voltage slowly falls to about 174v over next few hours. When car started I allow normal IMA low soc forced charge for the first half mile which pushes voltage well up but within spec giving the positive recal.

Drove to work today in a balmy 11C. Battery much more lively giving 75% assist. As we all know warmer weather improves things anyway for the Insight and meter was pegged at 140mpg+ for most of the 13 mile journey. KWH consumption also coming down, only used 1.3kwh yesterday for my 26 mile commute.

Done about 700 problem free miles now since install, including the week long freeze when low (70C) engine temps due to the small amount of fuel being used was a potential issue, mpg for the 700 miles is creeping up, now 91mpg (US) 110mpg (UK)

No autostop though presumably due to soc only three bars, I might have to include FAS if the bcm fooling plan does not work. Trouble is now i'm too busy enjoying the car to work on it I'm probably going to leave it in analog mode until weather is a lot better and I have tried the bcm experiments.

After the months of work it's such a relief to get it working that i've run out of steam temporarily

Edit

I also though about buying a bargain 20 pack of the pp3 9v alkaline cells and making up a simple test rig to plug into the bcm giving the appropriate voltages. I can use them later around the house/shed.

Edit

Thinking about the bcm potential divider if I used a variable psu. I do have a mains powered 0-300vd dc lab psu so i was thinking about 10 x10k 1% metal film resistiors in series to give the tap points.

This works out at 180v/100k ohms total resistance for a current flow of 1.8ma and a power disipation of 325mw.

Only problem is this only works in the garage So the mobile test 20x9v battery pack may be best.