Why this happens
A charger converts mains AC to the DC your battery needs, and some energy is lost as heat in the process. Many chargers have a cooling fan that runs or speeds up during charging, and the case often feels warm. Problems start when ventilation is blocked, the fan fails, dust builds up or an internal part begins to fail, which shows up as excess heat, new noises or smells.
What you need
Tools
- Infrared thermometer (optional)
- Soft dry brush
- Torch
Materials
- Dry cloth
- A hard, non-flammable surface or wall bracket to place the charger on
Before you start
- Never open the charger case; it contains mains voltage and capacitors that can hold charge.
- Do not cover the charger or charge it on soft or flammable surfaces.
- Do not use a charger that smells of burning or crackles.
- Only replace the charger with a manufacturer-approved one for your battery.
Step by step
- 1
Know what normal looks like
During charging, it is normal for the charger to feel warm and for a fan to run, sometimes changing speed, and for a faint hum. Many fans stop or slow when charging finishes. Watch and listen during a few normal charges so you know what is usual for your charger. Note it in your battery log.
- 2
Give it room to breathe
Place the charger on a hard, flat, non-flammable surface, or hang it as the manual shows, with clear space around its vents. Do not put it on a bed, sofa, carpet, cardboard or seat, cover it with cloth or put it in a closed box or under the scooter seat while charging. Keep it out of direct sun.
- 3
Keep vents clean
With the charger unplugged from the wall and the vehicle and allowed to cool, brush dust off the vents and the outside of the fan grille with a soft dry brush. Wipe the case with a dry cloth. Do not open the case, push objects through the grille or blow compressed air hard into it; that can damage the fan or push dust inside.
- 4
Measure the case temperature
About 30 minutes into a charge, measure the charger case with an infrared thermometer, or hold your hand near it. Compare with earlier readings in similar weather. Warm is normal; a case too hot to keep your hand on, or much hotter than usual, is not. Also check the plugs at each end of the cable.
- 5
Listen for abnormal noises
A fan that rattles, grinds or squeals, a loud buzzing or high-pitched whine that is new, clicking that repeats rapidly, or crackling and popping are all abnormal. Note when the sound happens, for example at the start of charging or near the end. A fan that never runs on a charger that normally has one running is also a warning sign.
Tip: Record a short phone video of the sound; it helps the service centre identify the fault.
- 6
Use your nose
A smell of hot plastic, burning or fish-like odour from a charger often means a component or insulation is overheating. Switch off at the wall and unplug immediately if you notice it. Do not resume charging with that charger until it has been inspected.
- 7
Decide what to do
If the charger is only warm and the fan sounds normal, carry on and keep the vents clean. If it is much hotter than before after you have fixed ventilation, or makes new noises, or the fan has stopped, stop using it and contact the dealer for an inspection or an approved replacement. Do not repair or replace the fan yourself.
How to tell it worked
The charger sits in a ventilated spot, stays warm but not hot, its fan sounds as usual and there are no smells or new noises during charging.
Stop and call a technician if
- The charger smells of burning or hot plastic.
- You hear crackling, popping or a new loud buzzing.
- The case is too hot to hold your hand near, even with good ventilation.
- The fan has stopped on a charger that normally runs it, or the case is cracked or deformed.
Questions
My charger has no fan. Is it supposed to get warm?
Yes, fanless chargers rely on their case to shed heat and often feel warm. Give them plenty of space and keep them out of the sun.
Can I put a table fan next to the charger to cool it?
Extra airflow does no harm, but it should not be needed. If the charger needs extra cooling to stay at a normal temperature, have it checked.