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34 Posts
Discussion Starter #1
When Charging the cooling fan is on. Does it stay on for long after the battery is fully charged?

I have seen different answers in different places. Mine I think stays on, which is a right waste of of electricity - I guess it is about about 20W and if left over night would soon add up.

So what does yours do?

Premium Member
6,369 Posts
Non Twizy owner..

I was wondering initially why would you need a fan ,to clear fumes or something :).

I did a quick google.
Seems fan keeps battery cool when charging and after to get a better charge in and extend battery life.
Then theres things about battery temp sensor and OAT and the fan conrtnuing after charge until the battery temp drops below a certain level or gets within x degrees of the OAT.

Maybe the fan running time is dependent on what part of the country youre in/where you charge the car inside or outside/Winter or Summer.

To my electric car ignorance it sounds like its the opposite of a normal car.
Cold night hard on the petrol or especially diesel car battery,could be hard to start if the battery is on the way out.
Cold night : Happy electric car battery charging especially with a cooling wind and battery should get cold quicker than in a hot garage?


34 Posts
Discussion Starter #3
My question wasn't really about why there is a fan , that is obvious when you consider the amps flowing through. Look at how warm Rechargeable batteries get when fast charged or how warm the charger gets.

I was more interested in finding out if the fan should switch off after the charge and all has cooled down?

I don't want to have to wait up at night just to go and unplug it from the mains after it is charged to stop the fan running.

Thanks for your reply, the manual talks about optimum charging temps and about being in a garage when charging. It wasn't that warm when I last charged it and it was only a top up charge (15%) but the fan was still running several hours latter.

17,106 Posts
As above.

I presume it's because all batteries heat up when being charged (work is being done, in storing the energy, and this is lost as heat), and although it is 'wasting' electricity (or capacity), this has probably been 'designed-in' from a product liability issue (better to lose 5-10% from the range, rather than turn the Twizy into a BBQ).

There will be some form of temperature sensor which will determine if/when the fan is needed, I'm sure.



17,106 Posts
I don't want to have to wait up at night just to go and unplug it from the mains after it is charged to stop the fan running.
Sorry, just noticed your post immediately after I had submitted my reply - maybe something along these lines is an option (there may well be more cost-effective outlets);

Premium Member
6,369 Posts
Heres something about software and the long charge quick charge and priming the on off times ? I didnt read thru it all and its for an electric bike but was shown on a twizy related forum.
Might be interesting to read anyway:
Perhaps Renault have some software related updates or fix (if the timer switch doesnt work out)
The dealer has loaded new software to improve the battery handling and accuracy of the fuel gauge. In
order to finalize the actions with this upgrade, please perform the following actions upon receiving your
scooter back from the dealer. Please add this to your owner’s manual.
1.0 DO NOT recharge the bike yet. Begin the battery management initialization routine by immediately
discharge the battery until the battery light (Red Telltale) illuminates. Then follow steps 2-5 to complete
the initialization.
2.0 Set a pre-charge cooling delay. This selectable pre-charge cooling delay has been incorporated into
the charging algorithm to cool the batteries prior to charging. This increases the charge efficiency. It is
recommended that a delay be used whenever possible and that the duration be made as long as time
permits. Set a pre-charge cooling delay as follows:
2.1 Unplug the bike.
2.2 Turn on the bike.
2.3 Pres and hold the SELECT (S) button on the right side of dashboard until you see the Set Delay
mode activated on the left LCD.
2.4 Set the delay using the H and M buttons. Press and hold H to increment by 1 hour. Press and hold M
to increase in 15 minute increments. The maximum delay you can set is 9 hours, after that it will go back
to 0.
2.5 Once you are finished press and hold the SELECT (S) button until you see DONE flash briefly on
the left LCD and the normal display returns.
2.6 Enable the programmed delay by pulling the left brake lever while turning off thee ignition key.
2.7 Alternatively you can enable a fixed 30 minute delay by pulling the right lever while turning off the
ignition key.
3.0 Fully charge the scooter using the charge delay.
3.1 Plug in the scooter.
3.2 The dashboard will turn on and you will see the initial check, then it will turn off and the plenum
fans will run.
3.3 Every 20 minutes the dashboard will turn on and the bike will check the battery temperature. If it is
below the set threshold, the plenum fans will turn off and the delay will continue with the fans off. If the
temperature is not below the threshold, the plenum funs will run.
3.4 At the end of the delay, the charger will begin a normal charge cycle. A the end of the charge a 1hr
post cool down will begin with the fans powered by the battery. This will terminate earlier if the
threshold temperature is reached.
3.5 The charger will then begin an equalization charge (this was initiated when new software was
loaded). It is recommend that you let this equalization charge complete. The duration is set to 4 hours in
addition to the regular charge time. However, if time does not permit, stopping the sequence will not
harm your scooter.
4.0 Within 24 hrs, completely discharge the bike again. Be certain the battery light illuminates. This
discharge does not have to happen in one ride, but do not perform an opportunity charge (short cycle)
until after the bike has been fully discharged.
5.0 Once the battery light illuminates the initialization is complete.
Notes: Unless you want to change the duration, the programmed delay will stay in the memory, so you
do not need to reprogram it every time. To enable the programmed delay, simply pull the left brake lever
while you are turning off the ignition key prior to plugging in the bike.
Alternatively, you can enable a fixed minute delay by pulling the right lever while you are turning off
the ignition key.
The software will keep track of the riding time. After every 12 hrs of riding an equalization command
will be sent to charger which will initiate an equalization charge after your next charging cycle
SW Changes
The main focus of this MC SW release is on better battery management and better fuel gauge accuracy.
The SW was designed to acclimate to the various states of health of the batteries already in the field and
to better protect from damage all new packs. The new SW incorporates better pre-charge cooling along
with continuous battery capacity measurements to prevent over charging and to accurately scale the fuel
gauge. The occurrence of the hot battery warning should decrease significantly.
The most obvious change a user will see is the addition of a programmable delay, during which time the
fans run off the batteries while cooling the batteries. The advantage to this is that it eliminates the extra
charge that was dumped into the batteries when the fans ran off the AC power, allowing for much better
cooling. Cooler batteries accept a charge much more efficiently and allow for more complete charges.
The “delay” function utilizes the instrument cluster LCD and the four IC button as a user interface. The
use of the delay is vital to maintaining a healthy battery pack. In addition, the delay can be used to start
the charge when electricity rates are lower.
The SW also measures the actual battery capacity during a full discharge cycle immediately following a
full charge cycle. This capacity is then shared with the charger so that the charging profile can be
matched to the battery pack. In addition the charger uses this value to accurately scale the fuel gauge.
Although the SW performs this measurement on an ongoing basis it is critical to follow the initialization
procedure to insure that the SW learns the pack capacity in the first few charge cycles.
The low battery measurement and management is much more controlled and does not require the battery
to be dangerously discharged to synchronize to the gauge as before. The SW looks for a low power
output when the pack is under a certain voltage. That is, when the pack voltage is less than a
predetermined value, the current output must meet certain minimum requirements. If it does not then the
battery is deemed discharged to a certain value. At this point the battery icon will illuminate, warning
the user that the remaining range is limited. In addition the minimum allowed pack voltage has been
raised significantly, preventing over discharging.
Once the SW is installed and initialized, the user will notice several differences. During discharge the
fuel gauge will no longer drop out at the end of the discharge. The user should consistently have
between 1 and 2 bars showing when the battery icon appears. The last bars will have useful charge
remaining. During charging, provided the delay is used regularly, the temperature of the battery should
be acceptable to allow a full charge and to prevent over heating of the pack during the end of a charge.
The pre-charge delay is programmed by pressing and holding the SELECT button on the IC until the left
LCD displays the delay info. The HOUR and MIN button are used to set the delay in 15 minute
increments. The delay value is limited to 9hrs and rolls over to zero at this point. Finish setting the delay
by again pressing and holding the SELECT button until the delay info is replaced by the normal display.
At this point the delay is set, stored in memory and enabled. The key switch must be turned off before
plugging in the charger otherwise no delay will be implemented. Once a delay has been programmed, it
can be enabled by simply holding the right brake lever while powering down. A delay with the preprogrammed
duration will be implemented. A fixed 30 minute delay can also be enabled by holding the
left brake lever during power down. The fans will run during this delay until either the temperature is
within 3 degrees of ambient or the temperature reaches 24 degrees C. The delay will continue even if the
fans turn off. Once the delay expires the charge will start.
The SW will keep track of riding time. Every 8 hrs, an equalization command will be sent to the charger.
For information purposes, when the kill switch is in the off position and the left lever is pulled, the
battery voltage is displayed in the estimated range field and the highest battery temperature is displayed
in the trip field (similar to when charging).
The motor controller fan will no longer come on immediately when the scooter is enabled, unless the
controller is above a threshold temperature. As soon as the scooter begins to move or draws a minimum
amount of current, the fan will come on at a default low speed as it did with previous SW. When the
scoot comes to a stop the fan will turn off, again, unless the controller is above a threshold temperature.
This basically masks any fan noise when the fan is not needed.

17,106 Posts
I completely agree.

I think a lot of this is uncharted territory for manufacturers and consumers alike, and early adopters like yourself, are paving an easier road for others to follow.

It may well be a faulty fan, so I would definitely check that avenue first, before spending any money.

I must admit, after reading Coup's last post - a petrol/diesel pump seems much simpler...


955 Posts
It may well be a faulty fan, so I would definitely check that avenue first, before spending any money.

I must admit, after reading Coup's last post - a petrol/diesel pump seems much simpler..
Something electrical from Renault could be faulty you say? Never.:d

4 Posts
My cooling fans run until the temp drops. The heat increases as the battery reaches full, so when charging is complete, the fans are still required - at least until the internal temp matches ambient.
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