Starting and charging
Generator Battery Charging System Repairs
We repair the parts that keep a generator battery charged: the mains battery charger, the engine’s charge alternator, and the cables, fuses and terminals between them. When the battery itself is finished, a replacement typically costs R900 to R2,800.
Callout fee waived when you accept our written quote. 1-year workmanship guarantee. See prices
- Charger, alternator and battery
- Battery replacement R900 to R2,800
- Standby sets included
- Onsite across Gauteng
Two ways to charge
Which part of the charging system has failed?
A standby generator charges its battery in two ways. The mains battery charger keeps it topped up while the set waits for an outage. The charge alternator on the engine charges it while the set runs. Either can fail, and so can the wiring, fuses and terminals that join them to the battery.
We measure the charging voltage at the battery terminals with the charger on, then again with the engine running. Those two readings tell us whether the charger, the charge alternator or the battery is at fault, so we replace only what has failed.
Battery replacement typically costs R900 to R2,800, depending on the size and type of battery your engine needs. We check the charger on the same visit, because a faulty charger will flatten a new battery too.
The charging system
Charging system parts we repair
A flat battery is the result. One of these parts is usually the cause.
Mains battery charger
We test the charger output and its fuse, then repair or replace a charger that has failed, charges too little or overcharges.
Charge alternator
The belt-driven alternator on the engine charges the battery while the set runs. We test its output and check the belt, the warning lamp wire and the connections.
Cables, terminals and fuses
We clean corroded terminals, replace damaged leads and blown fuses, and tighten loose clamps that stop current flowing.
Battery replacement
When a battery will not hold its charge, we fit the right size and type for your engine’s starter. Typical cost: R900 to R2,800.
Isolators and switches
A battery isolator left open, or one that has failed, keeps the charger from reaching the battery. We test it with the rest of the circuit.
Controller charging alarms
A charge alternator failure or charger fault alarm tells us which circuit to test first. We then find the failed part behind it.
Related Pages
Battery symptoms, starting and maintenance
- Generator Battery Not Charging Symptoms and causes of a battery that keeps going flat
- Generator Not Starting Silent, a click, or no crank
- Not Auto Starting Fails when the mains drops
- Starter Motor Repairs A click, slow crank or no crank
- Controller Repairs Charging alarms on the module
- Generator Maintenance Plans Battery and charger checks on every visit
- Generator Repair Costs Battery and repair price ranges
Common Questions
Questions about generator battery charging repairs
What does a battery charging system repair cover?
The mains battery charger, the engine’s charge alternator, and the wiring, fuses and terminals that connect them to the battery. We replace the battery as well when it has failed.
How much does a generator battery cost?
Battery replacement typically costs R900 to R2,800, depending on the size and type the engine needs. Your written quote sets the final price.
Why does my new battery keep going flat?
The charger or the charge alternator is the first suspect, because a new battery cannot stay charged without them. We test both before we fit another battery.
What is the difference between the charger and the charge alternator?
The charger runs off mains power and keeps the battery charged while the generator waits. The charge alternator is driven by the engine and charges the battery while the generator runs.
Can I leave a jump pack connected instead of a charger?
No. A jump pack turns the engine once. A working charger keeps the battery ready between outages.
The controller shows a charging alarm. What should I do?
Photograph the alarm and call us. It tells us which circuit to test, and we then measure the charger, alternator and wiring to find the failed part.
My battery is flat and I do not know why. What should I book?
Book a diagnosis. We test the battery, the charger and the charge alternator on one visit and tell you which one failed.
Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.
Service Areas
Onsite visits across Gauteng
We come to your generator anywhere in Gauteng, 24/7. Choose your region for local suburbs, call-out details and the faults we see most there.
What to send before we attend
These details help us plan the visit and bring the right parts. Send what you can on WhatsApp; if you can’t find the model number, we still book the visit.
- Location
- The suburb or site, so the visit can be booked in the right area.
- Make and model
- The generator brand and model, if they are known.
- kVA
- The size printed on the data plate.
- Fuel type
- Diesel, petrol, LPG, natural gas, or dual-fuel.
- Controller model
- The module name on the panel, when it is visible.
- Fault or alarm
- What the set does, and any text on the screen.
- Photos
- The generator, the data plate, and the controller or alarm. Send these on WhatsApp.
Book a Visit
Tell us how the battery behaves
Say whether it is flat after standing, whether a charger alarm is on, and whether a jump-start is the only way it turns over.
- Call
- 082 057 4605
- Message us on WhatsApp
What happens next
- We reply with questions about the generator, or to book a visit.
- A technician comes to you. For a breakdown we arrive within 1 hour.
- The fault is diagnosed on site and you get a written quote. No work starts until you accept it.
Charlie, lead technician: Degree in Mechanical Engineering, Degree in Electrical Engineering, Diesel Plant Fitter. Generator specialists since 2000.