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Twizy shut down when headlamps turned on

Hi all,

I had a rather frightening episode in the Twizy this evening where I put the headlights on whilst driving (as it was getting dark) and the car cut out completely. The display screen went dead and there was no drive from the car. Once I rolled to a stop, I tried restarting the car and the display screen was dead - nothing.

Fortunately, I had a friend come out to help and after disconnecting and reconnecting the 12v battery things were OK again.

The 12v battery is a few months old and is kept on a ctek battery conditioner, I have a battery indicator on the 12v which showed that it was at full charge. I am running the later bluetooth version of the PowerBox.

Just wondered if this has happened to anyone before or if anyone had any ideas on what might have caused this? Is there some kind of fuse that was tripped? Any thoughts much appreciated. I’m pretty confident that the battery was securely connected and am thinking a loose connection is less likely given that the power cut out exactly at the point I turned my lights on.

Also, when I broke down as I was on a hill I had to put the handbrake on - unfortunately I was then stuck with the handbrake on and unable to push the car due my being unable to take off the handbrake with no power to the car. I hear there is a method of taking off the handbrake without power - but understand this is a theft/security issue - if anyone could message me with the process to release the handbrake without 12v power it would be great to know should this ever happen again.



Sounds like a dead cell in the 12 battery that drops out under load. The headlights do draw a lot of current from a small battery. Also it could be that the DC to DC converter has failed. The traction battery when the Twizy is running should keep the 12V charged and run the lights.

Check the 12V battery voltage on and off load and with and without the Twizy turned. Under load (lights on) it should still be above 12V.

You can ‘jump start’ the Twizy to get the handbrake off.

If anyone is fed up of their Twizy I am looking for one, just let me know ! Cheers.

Thanks osbrook.

To follow on from this I’ve bought a battery tester and the 12v comes out fine with no dead cells. I have managed to replicate the problem. If I have the car stationary (fully charged 12v, fully charged traction) and leave the lights on for around a minute the car will shut down. Checking the 12v battery health on this it’s still around 98% charge so has not gone flat. Plugging in the car back to the mains ‘resets’ the car but then if I try the test again with the lights it will shut the car down pretty much instantly (notably not on side lights but on main beam).

A while ago the connectors on the 12v battery were cut off by a previous owner (to fit a cheaper battery with different connectors). The ‘correct’ exide battery was then replaced at a later date with new ring adaptors crimped on to the 12v cable from the car to make them work. I’m wondering if this could be the cause where they can’t operate under heavy load? I think I’ve seen other comments you’ve made on this forum where this might not cause issues but thought I’d check. I’m reluctant to change connectors again as I don’t want to make the wires too fragile/short through cutting and reattaching.



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You could!d try connecting additional wires to the battery and feed them in later in the circuit. Is. Via the 12v outlet in left hand glove box. You may be able to find some where better. That would split the current running in the current leads if you think that is the issue.

The 12v battery cannot alone power the headlights for very long. So if the battery is still charged as per your test then the DC to DC converter is working .

I still feel it is the battery failing under load.

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Hello Matt,

Recently I’ve installed an old school equalizer with an amplifier (old school as well) . Since I was very concerned about connecting the voltage wires to the 12 V batteries I decided to buy a pair of mini fuse holders to use the power Coming out from the fuse box, while installing them I’ve found many interesting things on the Twizy functionality, I found there is a 15Amp fuse with symbol of a display in the fuse box, when you take this one out of its place you get the same behavior as you describe, no display or function at all. I’ve also found when the power from each device short cuts the Twizy alarms . My believe is the power wire from the headlamps is shorting the circuit with another device, maybe the same as 15Amp hot side I’ve described before. What I would do in your case is to replicate the fail as you describe, with the Twizy alarmed check continuity (With a. Multimeter) with all the leads in the fuse box if you find a short circuit there you can start looking for the fail in the Twizy wiring. Good luck, I hope you find the cause soon.


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@osbrook many thanks for your help, useful tip re: the additional wires. I’ve ordered a new 12v battery to eliminate (or hopefully fix) the potential fault in the battery itself. It should be arriving in a few days, stock allowing.

@quiquemeneses75 - thanks Enrique, that’s very interesting. I’ll check the fuses as well - probably useful to get some spare fuses in any case. I’m quite tempted to switch out the headlamps for the LED ones so will also check the cable route at the same time.


Just to conclude this thread, I’d found that the previous owner had added some ‘extension’ cables onto the original 12v connectors from Renault. I hadn’t noticed that further up the extension cable (which was wrapped in the same factory black insulation) the original connectors were still in place and the cable hadn’t in fact been cut. Having revealed this the extension cables were heavily corroded and pretty much came off. I cleaned up the original connectors and put them directly onto the battery and it all worked fine.

Kicking myself that I hadn’t seen this earlier, thanks all for your help on this topic.



Any connections around the battery need to be checked due to damp and corrosion at least once a year , the battery area can get very wet.

That’s a good result and a fortunate find. Thanks for updating us.
Not only has the true problem been found, but the original leads were still there (extended rather than cut by the previous owner, very considerate of them.)

I have run a separate set of wires from the battery up to the glove box for the purpose of easy access charging or testing. The +ve wire has a built-in fuse holder at the battery end, i think i got it from Halfords. Its been useful on several occasions and is fairly easy to install.

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make sure the fuse holder is water proof if its located near the 12V battery.

Thanks kEbV.

I’ve added a volt meter display (only £8 on ebay) so I can see if things are getting low and I do leave the car overnight on a CTek battery conditioner now so (touch wood) I’d only see a breakdown on the basis the 12v battery fails or the connections to it have issues.

Your approach of running a second 12v battery cable up through the glovebox is very attractive. Effectively means if there are any issues with the main 12v battery you can ‘jump start’ off of a second battery without the need to take the front panel off etc. right? As per a separate post I’ve been looking at the very compact LiOn batteries available on ebay that could do the trick (albeit at a cost of around £100) when connected. I believe the battery could then sit (disconnected) in the glovebox ready to connect if required.

Was it just 12v cable with a fuse in-line you purchased? What fuse rating did you use out of interest?



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Hi Matt,

Correct, the easy access cable helps give access to the 12v battery’s terminals without dismantling the car. I’ve made the cable long enough to reach the ground beside the rear right wheel, just in case. I think I’ve got a 3A or 5A fuse (enclosed in a waterproof holder, as m1n1s says).

I managed to get a few pictures of the route the cable takes and I will try to post them when Steve Jobs and Bill Gates can agree to let me copy and paste them to my PC!!
I’ll start a new thread in the week (there may even be a similar one from 2015 which would have given me the idea back then).

I have a very similar plan to you regarding the Li-Ion batteries from the RC hobby world being a back-up “12V” source, as long as a suitable DC-DC converter and voltage & current limiter is used. I’ll pop you a PM too.


I have today added a solar 12v charger to the car. This was via the 12v cigarette lighter. However it immediately through up error codes.

I have a new 12 exide battery - which has drained in 2 days. Powerbox shows a 8amp draw even when the car is stationary with no lights on. Sure this is too high.
What does anyone have as a reading?

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i’m guessing the powerbox is draining the 12V battery if left connected all the time?

the usual drain on the battery is low with the immobiliser dash red led.

A few people have found the powerbox drains the 12V battery if left plugged in. It’s just the way the powerbox opens the Canbus and so the Twizy consumes the power.