EV has charge but will not start: the 12V battery

The main battery had charge when you parked. Now the doors will not unlock normally, the dashboard flickers or the car will not show Ready. The small battery may be involved. An EV still needs its low-voltage system to work before it can use the energy stored in the main battery.

These symptoms need a proper diagnosis. A key fault or a problem in another electrical system can also prevent the car from starting. Tell the service centre exactly what works and what does not; a message saying "battery problem" is too broad to identify the failed part.

What the smaller battery does

The April 2024 Punch EV manual hosted by Sipradi describes two battery systems. The high-voltage battery powers the motor; the 12V battery supplies equipment such as lights, wipers and restraint systems. A DC-DC converter takes power from the high-voltage battery to maintain the low-voltage supply. Other cars can use different equipment, so check your own manual.

Having a charged main battery does not rule out a discharged or worn small battery, a connection fault or a problem with the converter. The workshop needs to check the low-voltage supply as well as the traction-charge display.

A parked car may use energy for monitoring, alarms, connected functions or other equipment. An added dashcam or tracker can also introduce a load depending on how it is installed. The drain needs measurement; a dashboard symptom cannot tell you which item caused it.

Record what happened before repeated attempts

Note when the car last operated normally, how long it was parked and whether anything was left connected. Photograph messages if the display works. Tell the assistance provider whether the car was exposed to flooding, an impact or recent electrical work.

Tell the technician whether the doors unlock, whether the display lights up and whether Ready appears. If charging also failed, give the charger type and any message shown. These observations are more useful than assuming the whole battery pack has failed.

Do not keep cycling the controls indefinitely. Repeated attempts may reduce the remaining low-voltage charge and erase the useful distinction between the initial fault and the later discharged condition. Follow the model's manual and the service centre's instructions.

If the car is in a dangerous road position, prioritise people and traffic safety. Explain the location and whether the vehicle can be moved using the approved procedure. Do not improvise towing because the wheels appear free.

Generic jump-start advice can be wrong

The Punch manual's emergency and towing section warns against jump-starting the vehicle and tells the owner to contact an authorised EV service centre if the 12V battery is completely discharged. Keep that warning attached to this model and manual revision. An online petrol-car booster procedure is not a substitute for the instructions supplied with your EV.

Other manufacturers may specify a controlled low-voltage recovery procedure. Use the instructions for the exact vehicle and seek qualified help. Do not connect to unfamiliar terminals, bridge fuses or use high-voltage components as a power source.

Also check whether the car may be used to assist another vehicle. A procedure permitted for a petrol car does not establish that an EV's low-voltage system can safely supply the same load.

If there has been water intrusion, unusual heat, smoke or damaged wiring, tell the recovery team before any electrical work. Do not bring the car back to life merely to see whether it will move.

Ask the workshop to find the cause

A discharged battery may need charging, testing or replacement. The workshop should establish why it was discharged. Did it fail its capacity or condition test? Is the charging/conversion system operating? Is an accessory drawing power when the car is parked? Is the vehicle following the expected sleep behaviour?

Ask for the measurements and proposed work in the job record. A new small battery may temporarily hide an unresolved drain. If the fault returns after a similar parking period, provide that history rather than accepting another identical replacement without investigation.

The correct replacement must meet the manufacturer's specification. Battery type, rating and any registration or reset procedure can vary. A physically fitting battery is not necessarily the right one.

Plan storage before leaving Nepal

If the car will sit while you travel abroad, ask the distributor for both traction and low-voltage storage instructions. The recommended traction charge does not answer whether the smaller battery needs inspection, an approved maintainer or periodic checks.

Do not disconnect equipment without understanding alarms, locks and required reset procedures. A relative asked to "start it occasionally" needs model-specific instructions and permission to operate the vehicle safely. Waking a car briefly may not do what a proper storage procedure requires.

Save the service number offline and learn the manual's access and recovery instructions before the key or low-voltage system fails. Paramount's MG service directory, for example, lists Nepal contacts for its service network. Owners of Comet and Windsor cars supplied by GO Automobiles should use their own distributor's assistance arrangements. Confirm the service number and coverage for your exact car.

Ask the technician to record the cause of the discharge and the work done. Keep that job sheet with the date and mileage. If the same fault returns, you can show how long the car had been parked on both occasions. For a longer trip away, use the EV storage guide to prepare a handover, then get the distributor's instructions for your model.