OVMS User Manual page 32

OVMS: Renault Twizy User Guide
Model
Peak current (2 min)
Boost current (10 sec)
Continous current (60 min)
The Twizy motor is rated for a maximum of 13 kW mechanical output, the maximum electrical
power to feed into it or get from it can be 18 kW. This value can be found in the SEVCON
configuration at SDO 0x3813.23 "Motor peak power" (and with a charged battery at SDO
0x2870.06 "Maximum battery discharge power").
The battery pack is sized at 7 x 966 Wh = 6762 Wh capacity (90% = 6086 Wh usable), so 18 kW is
~2.66C and translates to ~313 A at the maximum pack voltage of 57,5 V. Not surprising, SDO
0x4623.02 "Maximum battery discharge current" reads 314 A on a full battery. On discharging, the
BMS will reduce the available power in 500 W steps depending on SOC level and temperature (see
battery monitoring above). The maximum available discharge power observed yet has been 19.5
kW on a rather hot summer day with a full battery.
The battery charging limit default is set to 2.5 kW (SDO 0x2870.07) and 43 A (SDO 0x4623.01) on
a nearly full battery, and raises up to a maximum of 8 kW between 80% and 30% SOC (8.5 kW on
a hot summer day). This limit is basically under BMS control, but it seems the SEVCON will allow
a bit more for a short period of time.
So, these are the default current limits of the motor, controller and battery, and you normally should
not raise these configuration items or exceed these currents, otherwise you'll risk your components.
Higher currents lead to higher energy losses at resistances, faster raising temperatures and higher
wear. The SEVCON measures and estimates both its internal temperature and the motor
temperature and will cut back currents if necessary to avoid melting down anything, but higher
temperature differences always impose higher mechanical stress due to expansion and contraction
of materials.
Beginning with V3.7, you're free to control (raise/lower) the maximum current levels. The CFG
POWER command allows raising current levels up to the controller's boost levels, see command
description for details. The BMS current limits remain intact, so you will not be able to use higher
currents at all SOC and temperature levels. You can use the auto power control to compensate this.
A higher current level will add a boost to any torque configuration (even default), as the new current
level will be used for the motor launch phase (0 rpm). You can query the maximum motor current
using the SEVCON diagnostic log access (min/max values).
Speed
The speed limit serves two purposes: to protect the gear box and to protect the driver (you!).
The gear box seems to be bad, it is very loud and sounds out of the box broken. Word of mouth is
G4845 (Twizy 80)
450 A
540 A
180 A
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2019/05/02 RT3.9.1
G4827 (Twizy 45)
275 A
330 A
110 A