12V battery light comes on "when stationary"


(Pollus Fornerod) #1

Hi Twizy community!

Two weeks ago I bought a second (third-fourth) hand Twizy for a really nice price. The Twizy is from 2012 and has more than 50 000 Km on it’s clock, so some issues are to be expected. But it runs fine, especially since I freed up the front brakes.

Now I’ve got this issue: when I stand still, the red battery signal and the stop sign light up, together with the traction battery symbol with the exclamation mark.

All these warning lights go out after I drive off. But if I stand before a stoplight it comes on again.

I plugged a battery check thingy in the 12V socket and indeed, if I the car is stationary only one led (fair) is burning. The moment I drive off, the voltage rises to three leds (good), only to lower to one led when I stop again.

Yesterday I replaced the 12V battery with an original Renault battery and charged the Twizy overnight. This however did NOT solve this problem, the warning lights came on again this morning.

So now I wonder, should the the 12V battery not have been charged after a night on the mains? And why is it only charging when I drive and not if I stand still?

What could be wrong here, and can it be fixed?

Greetings form Holland!

(Hans de Vos) #2

I believe the 12V battery is only being charged when driving, not by the charger during charging.
You may want to try driving it for a while to see if that solves your problem.

Hans (also from Holland)

(Pollus Fornerod) #3

Hi Hans. Thanks!

That would explain a lot…I’ve just driven it for an hour and now the warning light stays off indeed. Strange though that you really have to drive, because just “idling” seems not to recharge the battery.

Oh well… if it works…

(Peter) #4

Mine’s just started to do this.

Also the battery warnings and stop light come on whilst charging!

I fitted a new 12v battery a few weeks ago but it did recently become fully discharged when I left the PowerBox turned on.

Having said that the 12v battery still seems strong at ~12.7v and can easily run the headlights and hazard lights without any dimming.

Hopefully it’ll sort itself also.

(osbrook) #5

A 12V battery that small will never fully recover from a big discharge. It’s capacity will be well down.
If it doesn’t fix itself there are a couple of things to try.

  1. take it off and charge for 24 hours
  2. Come and borrow my spare battery.

(Peter) #6

That’s much appreciated, thank you.

I have a battery maintenance charger, which runs a test, so will give it a go.

It’s odd as the 12v battery seems strong.

Also, there’s the random relay clicking sound when plugged in after charging is complete.

(Peter) #7

This is all slightly odd.

I removed the 12v battery yesterday, which was at 12.89v.

It only charged at my charger’s maximum 1.5A for around a couple of hours.

The charger then kept the battery at 13.99v overnight until I refitted it to the Twizy this evening.

Initially it seemed as bad as before but the more I drove the less the battery light came on. I can now leave the Twizy started but not moving for many minutes with no battery light and it’s charging the 12v battery as I have 14v+ at the 12v socket.

I thought all was well so turned the Twizy off and plugged it into the mains. Within a short while of charging the battery light came on.

It’s hard to believe the 12v battery is at fault as there were no such issues with the original 12v battery, which was so tired it wouldn’t allow the Twizy to start straight away.

The 12v battery fitted now is new although has been fully drained, just once, when I left the PowerBox on.

Having said that there does seem to be an improvement after removing and fully charging the 12v battery.

(osbrook) #8

@peter-ss The problem with Lead acid batteries is they breakdown under load, They can show a good voltage but apply a load and that soon drops.

Discharging a small battery like the Twizy has will damage it.

Put a load on the battery and see the reading then remove the load and check how fast it recovers. It should take a few minute unless damaged. There isn’t an easy test that doesn’t do more damage.

12.89v is high for a battery that has been off charge for at least 1 hour. Should be nearer 12.7V However we are guessing using the Voltage as a guide. I know it’s the best we have.

The improvement comes from it being a better charger. Really batteries need to go through a multi stage charge. Load to 14.4v then bulk load at 13.7v and then a maintenance charge. If you have a fancy charger or even a solar panel charge controller then these will do the multistage and a cleaning phase (AC!) to maintain the battery. Lithium Batteries have a different stage charge. They are constant current rather than constant voltage. They should also finish with a balancing phase.

(Peter) #9

I’ve just taken it for a drive and it seems slightly worse.

Could I please take you up on your kind offer of borrowing your spare 12v battery?

I don’t have any plans this weekend so could nip over with the Twizy any time.

It would only take a few minutes to see if it makes a difference.


(osbrook) #10

Yes but not this weekend :disappointed_relieved::disappointed_relieved:

(Peter) #11


I’ve got it on the ramps to do some checks.

Found out I have a 2013 charger, which explains why it doesn’t keep the 12v battery topped up whilst parked.

Phoned Renault who quoted me £725 for a new charger although not sure if it will be plug and play or will need coding to the vehicle.