Battery flat again and will only charge to 98%

I think my 12 volt battery at one year old has had it chips! If I leave le twiz a week its flat and today when I went to charge him he has only got to 98 % so something is amiss. He has been on charge from one o clock and at nine I have just taken him off charge not good on a one year old low mileage twiz eh

Hi Peter, the 12v battery might need checking for distilled water levels - most batteries should last at least 3yrs or so, never seen one die in 1yr - unless there is another problem in draining it while sitting. In winter 12V batteries don’t do as well as the summer due to low temps affecting the battery. The Twizy’s brain won’t allow you to over-charge the main battery, so the charging will turn off at 98%. When I return from work I charge the Twizy, it does its cycle for about 3hrs, and in the AM I unplug/re-plug it back in, and it tops it up before I go to work (still stops at 98%).

This is a known bug that should be fixed by Renault on guarantee.

How does he know that the 12V battery is only charging to 98%? I thought the indicator showed the traction battery not the 12V one?

mine stops at 98%, but mine is nearly 4 years old.

Renault will only replace at 70%. One of the good things with the battery rental.

My twizy has always charged to 100% also I only have to leave it a short time and the 12v battery is flat! I am also having problems with my regen and wonder if the two are linked?

Now that the weather is warmer the battery issue has sorted itself out now, also the range is getting larger by the week :grinning:

Mine also stops at 97-98%. I tend to unplug after 3 hours as I can’t see the point in leaving it on for longer and even if I do, it makes no difference. However, mine is 4 years old in a few months so I guess this is the reason?

I’ve also noticed that if I forget to unplug (i.e. over night for example), the fan has often started up again? Is this right?

The fan tends to stay on until you unplug.

Mine doesnt Chris as soon as it is charged it stops however when it was only hitting 98% it was staying on for longer. My regen is still playing up however the build quality and repair quality does leave a lot to be desired

Leave it to charge even if it stops at 98% it is the BMS that balances the battery for you so that all cells become equal. the BMS on a Twizy is not as powerful as it can take many hours to calibrate the batteries (It can to even take days) It tries always to balance the battery when approaching a 100% it’s one of the reasons why the last% takes longer time. is your batteries very out of balance then the rebalancing takes a longer time.

if they then never reach 100% so there are some of the battery cells that have less capacity than what they should have
You should then also noticed it on the bottom of the battery %. the last 10 to 20% will go very fast

The trouble is that sometimes it turns itself off at 98% so i didnt have that option I thought my problem was the 12 volt battery. My problem has gone away with the warmer weather but I bet it returns next year when it gets cold again

I am pretty sure that if the display shows 98% or 100% it have nothing to do with the capacity of the drive battery. When your battery dies it will also show 98% or 100% when it is full chanced (you can have a full charged battery with a low capacity).
The only way (I know) you self can check the status of the drive battery is to drive the car completely empty, and then measure how many Kw/h it spends while charging and subtract the energy loss in the charger (unknown factor). The result should be around 6Kwh as far I know.

My twizy during bulk charging draws 2.1kw so this is for most of the 3.5 hours. ie. 7.34KW Then there is approx 20W draw for the fans after bulk charging is complete.

@kennethnilsen69 I had suggested a few years ago that the Charge fan’s staying on was part of the Battery Balancing as it varies in length each time. Glad someone has confirmed it.

So, in summary then, should I just leave the Twizy plugged in and left charging all the time? I use it most days I must say so I guess the max it would be on charge would be 15 hours?

If my Twizy was like a lot on here 3-4 years old things would be ok but it is just one year old and shouldnt really be doing the things it is or was

It will shut off eventually. The more times you leave it to balance the shorter the time before the fan cuts out. Having said that mine is still about 4 hours.