Power Gauge

[evanmjones]

Couple of interconnected issues here. Mind if I ask for comments?

Van fully charged overnight. Drove 10 miles, gauge reading about 85%. Put van on charge for about half an hour, now reading a little over 90%.

Drove to a meeting about 15 miles away; on the way back, about 5 miles short of home, the econoscope lamp and the traction battery discharged lamp came on. Power gauge was still reading about 30%.

This was a first for me, the econoscope lamp and the traction battery discharged lamp have never come on for me before, even the time last Spring when I'd done 51 miles and the gauge was showing about 3% left when I turned into the drive. I'd assumed that the force-economy system wasn't working.

OK, so it's cold at the moment, but the van would normally eat 42 miles (the exact trip odometer reading) no problem, and it had a short boost charge. Should I be worrying about anything to do with the batteries?

Secondly, the power gauge has always been very reliable and seems to go down in appropriate steps with the milage (I always reset the trip odometer to zero after a full charge) the econoscope lamp and the traction battery discharged lamp coming on while it was showing 30-ish% left has shaken my faith in it a little.

Finally, is there any way to over-ride the force-economy driving thing? It's a pain going up hills with it. I'd like to be able to say to it, "I'm over 21 and I take full responsibility for running out of sparks, now get in the yellow".

Ta.

Evan

[Flying John]

It means the terminal cell voltage dropped to about 123 - 125 volts for a few seconds and this trips the warning lamp. You can trick it but at your own risk as their maybe a cell or two thats very low or possibly reversed.

Pop the bonnet and pull the traction fuse. Disconnect the large multi way connector from the RHS of the top of the control box - its a fiddle and you may need a coin to release the catch.

Go switch the ignition on, then off again. Re-connect the multiway connector and then put the fuse back in.

Drive away real easy, because if you put your foot down the low voltage will be sensed and it will happen again.

John

[timpootle]

John, your electrical reset procedure is more long-winded than that usually described on here. Does it do anything more?

The usual one is:
1)Pull traction fuse behind aux battery.
2)Disconnect aux battery negative lead.
3)Wait 30sec ~ 2 mins
4)Re-connect aux battery negative lead.
5)Re-install traction fuse.

No messing with calculator board multiplug, nor ignition switch. Works for me, with the same caveats you gave about killing already weak cells.

[Flying John]

Hi Tim,
I think its easier to unclip the multiplug and lift it up than disconnect the 12v battery. You dont have to turn the key in the ignition, but I find it seems to have the effect of cutting down the wait time to a few seconds.

[Andy B]

In this weather i find the charge light coming on at around 40-50% (battery temp around 2-8 degrees). The light comes on at 137V but only if the charge is below about 60%.

When it died 1 mile from home I pulled the traction fuse waited a few seconds, reinserted and this was enough to cancel the charge light without touching any other cables.

Fully charged and unloaded the voltage is 185V and when the charge light is on 155V unloaded does this sound about right?

[Flying John]

Perhaps they all differ Andy. I have never had the yellow "dot" or the charge lamp at below 50% charge. I monitor the voltage constantly and typically these are the voltages.

186v - just completed charge
200v+ - just completed charge and within first mile of home with regen operating.

from 100% - 70% on power meter, 165v - 155 volts on green band and some yellow load on meter.

from 70-% - 45%, 155 - 140 volts green band some yellow
from 45% - 25% 150 - 130
from 30% to recharge 140 - 123v

Light comes on in the 120 - 125 volt range after some seconds at higher load as you have to put your foot further down to get anywhere so the power meter goes into the yellow and red.

John

[ChrisB]

Personally I would'nt try to defeat the limiter, its there for a reason

If its come on then as john says there must be a battery or two that will be well down or even going into reverse polarity and I'm pretty sure this makes them consume water at a rate of knots and will cause them to fail early, bearing in mind you cant get replacements then do this at your own risk

A half hour charge really doesnt do much TBH, at best you'll be looking at adding an extra couple of miles at the most.

You dont actually say how cold it is/was, mine below 5C and driven carefully returns about 40miles, also it depends if the batteries where warm when you went for the first drive ie they had just come off charge, mine will only do about 35miles if I drive it and they are stone cold.

ChrisB

[evanmjones]

Thanks all, that's helpful. There's a few things there I hadn't really thought about.

Cheers,

EVan

[Andy B]

I monitor my voltage as well John.

"186v - just completed charge
200v+ - just completed charge and within first mile of home with regen operating.
from 100% - 70% on power meter, 165v - 155 volts on green band and some yellow load on meter.
from 70-% - 45%, 155 - 140 volts green band some yellow"

Up to this point my voltages are pretty much the same.

"from 45% - 25% 150 - 130"
Funny how my charge light comes on at exactly 137 volts and yours at 120 - 125 volts.
Seems a rather large difference, I could certainly get a lot more range in this weather if mine didn't come on so soon (around 30 miles).

Anybody else monitoring their charge light voltage for comparison?
Mines a 53 model BTW.

[Flying John]

As you say interesting.

Nicads should only be discharged to 1v per cell and that is 135volts as we have 27 x 5 cells = 135. But as we have 135 cells you only need .05 volts per cell drop to get 7volts difference on the total bringing it to 128. So maybe the measuring isnt too accurate on board.

As my state of charge gets lower I am extremely careful when the voltage goes down too far under load and can "nurse it" down lower than 135, provided i do not sustain the lower voltage with high current draw for too long.

I just wish I had a voltage monitor on each pack. Perhaps thats the next job to bring a fused pair from each battery pack to a double pole break before make switch, so I can monitor each pack as it will get too crowded to have a voltmeter for each pack.

John
53 Reg Blingo too