Charge Gauge Malfunction

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LeftieBiker
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Charge Gauge Malfunction

My Leaf-powered VX-1 has been virtually trouble-free, until this Spring. First I noticed that the clock was off by about three hours. I reset that after my first ride, and thought I was good. I just wasn't paying attention... My second ride was very pleasant: I charged to about 15 bars because I knew I'd only be riding about 30 miles, and the ride itself was fine. As I was heading home, though, and with 4 charge bars still showing on the gauge, the bike went into a greatly reduced power mode. At first I thought that the controller was hot, but there was no sign of that, and no warning lights. Then I looked - finally! - closely at the voltage display. I usually watch it, but this Spring I've been preoccupied, and the weather was so beautiful that I wasn't watching the instruments much at all...anyway, the voltage was at about 114 volts, instead of the usual 133-142. Finally, I realized that I was low on charge and the gauge was wrong. I limped to a local firehouse, where I was very lucky to be allowed to charge for 35 minutes before riding the last 9 miles or so home. The total ride distance was only about 27.5 miles, but without that charge I would barely have managed 20 miles. I immediately charged it back up to about 138 volts, letting the pack cool before charging it a bit more the next day.

So, given the clock glitch and the lack of warning lights, any ideas? The bike was stored this Winter with something like 12 bars showing, in a garage that only rarely, briefly got below 32F. My plan, when I get the time, is to fully charge the bike and let it equalize, then measure the cell voltages through the balance leads after a brisk ride. Is this more likely to be a weak or low cell in the pack, a firmware issue, or something else...?

martinwinlow
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Re: Charge Gauge Malfunction

Assuming there is nothing wrong with the pack (do you have a BMS - if so, what did it have to say about the health of the pack?) it sounds like the 'fuel gauge' which works on coulomb counting (ie counting Ah in and out) has got out of synch with the actual charge state.

In a stock Vectrix, the manual recommends occasionally discharging all the way until the red warning light comes on and then to fully charge it which re-synchs the gauge. With much bigger LEAF cells, the stock BMS has gotten hopelessly confused. Depending on your firmware, you might be able to reset the cell size to match the LEAF cells (if you haven't done this already) so what remains of the stock BMS can cope better.

The only way I know (and there may be others) to sort this would be to use the diagnostic software to reset the fuel gauge to either empty - if the bike is fully discharged - or 100% if the bike is fully charged... but this will only work for a while before it all goes out of whack again (assuming the firmware thinks it still has 30Ah cells - or whatever they originally were - in there).

Regards, Martin Winlow
Herts UK
evalbum.com/2092

LeftieBiker
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Re: Charge Gauge Malfunction

The bike has no BMS, just balance leads. It has lithium firmware. I don't remember if the firmware is from Vectrix or a third party - I think the latter. It has a 60AH pack but is set for 40AH, IIRC, to give, ironically, a margin for reserve. I guess my first step will be to check the AH setting, but even if that jumped to 60AH the gauge should be more accurate, not less. Then I'll fully charge the bike, run it hard, then check the cell voltages. If no issues there, I will use the diagnostic software and cable to reset the charge gauge when the bike is full. Can anyone briefly explain how to do that?

martinwinlow
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Re: Charge Gauge Malfunction

Having 40Ah set in the firmware with 60Ah cells will do it!

Go here to download the diagnostic software and its manual... https://service.vectrixparts.com/knowledge-bases/2/articles/5-vectrix-diagnostic-application

You will need a PEAK PCAN cable to use it (expensive ~€200) - https://www.peak-system.com/PCAN-USB.199.0.html?&L=1 (the same as Vectrixpart's €270 one!)

Install the application and run it (having connected the PCAN dongle first).

On the 'Dashboard' tab, enter the fuel gauge setting you want to set the fuel gauge to in the box below the 'Set Fuel Gauge' button and then press that button.

Done.

Regards, Martin Winlow
Herts UK
evalbum.com/2092

LeftieBiker
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Re: Charge Gauge Malfunction

"Having 40Ah set in the firmware with 60Ah cells will do it!"

Don't you mean having it set to 60AH when the pack is 40AH will do it? I don't see how having it underestimate the capacity would make it over-report it. Anyway, I have the software installed on a laptop, and have the cable and manual. I just wanted assistance with doing the job. Thanks. I'll start with checking the capacity setting.

martinwinlow
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Re: Charge Gauge Malfunction

Hi,

No, I meant setting the firmware to see 40Ah cells when they are actually 60Ah ones will cause the problems you have with the gauge getting out of synch. M

Regards, Martin Winlow
Herts UK
evalbum.com/2092

LeftieBiker
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Re: Charge Gauge Malfunction

Between the setup working fine for two plus years, and the clock malfunction that happened at the same time, I'm inclined to think that this isn't the cause. Still, I'll consider changing it to 60AH (more likely about 54 AH now for the pack) and not using the last two charge bars.

R
R's picture
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Re: Charge Gauge Malfunction

Seems faulty cpu DC-DC from charger. Cpu only works when powered from AC-DC, luckily allows charging. gauge is only MC controlled, works as voltmeter, right? 0=102V. est range works?

LeftieBiker
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Re: Charge Gauge Malfunction

I did a cell voltage test last week, after a full charge. I ran the bike a bit too hard and got the up strt message and then batt hot (it was in the eighties outside), but got home ok with about 35% charge. I was only able to test 32 of the 36 cells because of the way the balance connectors are set up, but they all were within 1.5mv and almost all were within 1mv of each other. That and the range seemed fine, the gauge seemed fine. I'm going to consider this a mid-Winter storage glitch unless/until it happens again. You can be sure that I'll be watching the voltage more than the gauge from now on! I have experience doing that with my crappy ZEV 5000.

R, on this firmware the voltage display replaces the range display.

boeingpilot
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Re: Charge Gauge Malfunction

Wow, my bike is setup the same (Leaf) and out of winter storage did the same thing.

I did not do a full charge. Ran out of range with 5 bars still showing and the pack was at 114v.

I believe doing a full charge will resync everything.

2009 Vectrix VX-1 Leaf Conversion
1983 Lambretta Lynx
1980 Vespa P200
2013 VW Jetta Hybrid

LeftieBiker
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Re: Charge Gauge Malfunction

It seems we both made the exact same mistake, but both got lucky! I for one will be watching mainly the voltage display from here on in...

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