Strange problem with e4 2006 Gem, something smells like burning

GEM Forum
1

Today I was out trying my new lithium batteries, fully charged to 82V. The gem speeds away really good, I turn the lights on and everything seems fine. Max speed now is just 45 km/h, but it gets there fast.
After just a a kilometer of runtime, something smells like it is burning plastic, So I stop, power it off and go around and look and smell, but can’t find anything. When turning it back on again, it just clicks, the screen flicks on for a moment and then it dies… I try several times, it just blinks and then dies. I try to turn main power on and off but nothing.
I keep smelling cables, and decide to disconnect the dodgy 12v wires going to the headlight and the taillights.
Then it comes back to life. By the way, nothing is hot, the motor and the controller are cool to the touch.
I hurry home in semidarkness. But now it just goes 25 km/h and the pickup and acceleration is not as good as before, there are no icons, or turtle mode on the display. And the battery voltage is at a steady 80 volts. ( victron BMV in the dash)

What could possibly cause this issue? The gem has ben sitting for about 3 years before I took over it. outside unfortunately. But it has been running good for last couple of days.

Can it be the ignition switch? But that wouldn’t explain why it was slower on the way home. Or is it the entire dash panel that has electrical issues?

2

Check the main contactor coil for heat.

3

Ok. thx Is that a common problem?

4

Wouldn’t cause your symptoms, but can smell hot.

5

I agree, melting plastic/wires is a scary smell.

Which lithium batteries did you install? Describe your setup a bit more.
You said you checked “everything”?. Did you check your connections on the cells? The man contactor? The controller?

Not that it would cause all your issues,
But what do you mean by dodgy headlight wires? Did someone just tap off one of the cells?

Slower?-
By chance did you flip it to Low (turf) mode?

6

Im using Li-ion 75ah modules. They are rated for 450Amp cont discharge.
All the battery wires are good and thick. No draw from individual cells, just one pack. Installed it myself.
I looked and felt on the wires to and from the controller, sniffing also. I ripped the dash of and looked and smelled and felt the contactor. All was cool to the touch. Im sure it was not in turf mode. tried flipping it between them and there was no change.

Is It usual with wiring problems in the steering column. behind the key?
Today it felt good again.

Dody 12v wiring. well someone thought it was a good idea to move the taillights and also most of the lamps does not work in the front. I noticed one wire that was lose also.

I used the original 250amp fuse from battery to motor and controller.

7

I doubt it will be anything in your steering pod. That is all low current and not really prone to heat issues unless someone got in there and left a few bare wires. If there was a problem it would probably blow a fuse. However there are known issues with the key switch going bad. Nothing that produces a plastic smell.

What are you using for lighting? Done by previous owner? Aftermarket? LED? How are they hooked up and switched? Inspect and understand all wiring hacks done by PO and even professionals. I’ve seen some pretty edgy stuff.

Losing all power
There are 3 connections that are really tough to get to on the front of your fuse block(PSDM). One +72v, one -72v, and a Ground. It involves pulling off the lower section of your dash (kick panel?). Yes, the connections are mounted in plastic. If they get loose, they melt stuff down there. Look for signs and check to make sure they are tight. Not only the ones on the front, but those studs go through the plastic casing and the PSDM board is screwed to the back of the studs. I recently came across a few pics of the boards burned because of loose connections.

If you are out cruising around and lose power again, give the lower fuse panel area a whack with your fist and see if power comes back on.

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I find this statement odd

Im sure it was not in turf mode. tried flipping it between them and there was no change.

This may be a BIG clue. Does this switch normally work? Please clarify- When you were limping home the other night you tried flipping the switch and nothing different happened? If sounds like something may have been holding you in turf mode.

There is another test we can do next time this happens.

Another thought,
What motor are you using?
When was the last time it was serviced/cleaned/looked over?

Odd theory:
Could you be smelling ozone? It sorta smells odd and could be mistaken for burning plastic. It is possible that you have a brush getting stuck and beginning to arc due to not good contact. In the motor there are two sets of windings, fields, and brushes in there (essentially two motors in one case). If you are losing a brush it might be you are running on 1/2 a motor.

If you have a sheet metal inspection cover over your brushes remove it and take the car for a spin. It probably won’t do it right away since your car now feels good again so you need to look for big blue flashes when it happens. If you drive around with the top of your dash off you might be able to see it while driving.

Report back your findings so future readers will find this useful.