Car & Van Battery Replacement

An efficient battery is vital to modern vehicles; they simply won’t start or operate without it. The starter motor pulls a tremendous amount of power from your battery when you start the car. Frequent short trips, especially in winter when the headlights and heater are running all the time, mean that the battery is constantly being drained. Under normal conditions, the battery is running down and being charged up again by the alternator as you drive the car. However, as the battery gets older, the charging process becomes less efficient and the alternator can’t get the power back into the battery as quickly as it is being depleted. An old and worn battery either won’t fully charge up, or won’t hold on to a charge, even if you put it on a battery charger. There are other reasons why a battery goes flat – maybe the alternator is faulty, or not operating properly. Whatever the reason for a flat battery, the worst time to find you have one is when you have somewhere important to go, and your vehicle won’t start.

You could be stuck at home with a flat battery, broken down by the roadside, or simply aware that your battery is starting to fail. The sensible thing to do is to call on an expert for help with your flat battery problems, so contact a member of the AutoMend network. With more than 9,000 mobile mechanics and garages spread across the UK, we are here to help you. We insist that all the members of our network are professional car and van mechanics, holding appropriate industry approvals and offering second to none customer service at value for money prices. You can trust our members to get your vehicle back on the road with minimal delay.


Even a healthy battery benefits from a top up charge from time to time. To charge your battery, you will need to disconnect it, and this means that the electrical systems in your car will be shut down. You may need to input a code to start some of these electronic systems up again (for example radio, entertainment systems, sat nav etc.) after a shut-down, so make sure you have access to the codes before you disconnect. In some cars, disconnecting the battery makes the central locking system lock the car, so always make sure the keys are outside the car.

You can charge the battery in situ, provided your charger can reach a source of mains power. Ideally, you should disconnect the battery leads, but if this is not feasible, unplug the negative (-) lead. All chargers are different, so you will need to read the instructions that come with your charger, and also ensure it is fully compatible with your battery.

Ensure the mains power is switched off before you begin to attach the charger leads to the battery terminals. The leads will usually be colour coded, so attach the clip of the red lead to the positive (+) terminal and the black to the negative (-) one. Switch the charger on at the mains, and check that the charger is working (there is usually an indicator light). If the charger is not working, switch off and then re-connect the lead clips, making sure they connect well with the battery terminals. It is important to connect the charger correctly, or you risk damaging your car’s electronics.

Leave the charger to work for the requisite amount of time (the instructions will tell you how long this will take). There is usually some kind of indicator to tell you when the battery is fully charged. Once the battery is charged, turn off the charger at the mains and unplug it, and only then remove the clips from the battery. Re-connect the battery lead(s) and then see if the engine will start.


If charging your battery hasn’t solved the problem, then there is something wrong, and you could need a new battery. You can replace your own battery, but batteries are heavy (they have lead plates inside), they are full of corrosive liquid, and need careful handling using protective gear. You also need to ensure you buy the right replacement battery for your car – get it wrong and you risk damaging the sensitive electronics in your car. You will then need to dispose of the old battery properly to avoid environmental damage. A much better option is to contact your nearest AutoMend vehicle repair and maintenance specialists and let them do the job for you. They have the expertise to source the perfect battery for your needs, fit it for you and then safely dispose of the old one – job done, and no hassle.


In an emergency, knowing how to jump start your car can be very helpful. It can enable you to get out of a tricky situation at the roadside and allow you to get your vehicle to a garage for repair. All you need for a jump start is a set of jump leads (it’s a good idea to carry a set for emergency use, keep them with your spare tyre) and a willing assistant who has a car with a fully-charged battery. We’ll call the car with a full battery the donor car, and call the car with a flat battery the patient.

The order in which you connect and disconnect the jump leads is critical – get it wrong and there is a risk of electrocution, or some spectacular sparks. A jump lead set has 2 leads; one red and one black, each of which has a crocodile clip at either end.

Position the donor car as close to the patient as possible so that the jump leads can easily reach the batteries of both cars. Switch off the ignition on both cars. Now begin to attach the lead clips, sticking strictly to this sequence:

  • Red (positive) lead to positive (+) terminal on the patient. Other end of red (positive) lead to positive (+) terminal on the donor car.
  • Black (negative) lead to negative (-) terminal on the donor car. Other end of black (negative) lead to an area of bare (exposed) metal on the patient.*

* This area needs to be away from the battery and avoiding any moving parts.

Ensure everyone is standing clear, then start the donor car’s engine and allow it to run for a few minutes to give the patient’s battery a chance to charge up a little.
Turn off the donor car’s ignition and then disconnect the cables IN REVERSE ORDER to the way you connected them.

The disconnection sequence is:

  • Patient black (bare metal) lead.
  • Donor car black (negative) lead.
  • Donor car red (positive) lead.
  • Patient red (positive) lead.

If the jump start has worked, you will be able to start the patient’s engine, so drive around for a little while to ensure the battery gets topped up. This usually takes around a quarter of an hour, so don’t switch off straight away.

If the jump start hasn’t worked, you may have a defective battery and you will need to call for help from your nearest AutoMend garage.


A bump start is basically giving the car a push, and then starting the engine while the car’s moving. Bump starting will only work in some cases, and only for a petrol-engine vehicle (it won’t work for a diesel engine).
If you want to give a bump start a try, put your car into second gear. Put in the clutch, and switch on the ignition. You now either need one or more people to push the car while you disengage the brake, or you need to let it roll down a hill.

Once the car is rolling, let in the clutch and press the accelerator. If the bump start is successful, the engine will start, so keep driving, don’t stop and don’t allow the engine to stall.

Entertaining though bump starting may be, it’s not a process you want to have to rely on. The sensible thing to do is to get your battery thoroughly tested by an AutoMend expert. They will be able to tell you whether it needs replacing, or whether you have another underlying problem causing a flat battery.


A standard car battery consists of 6 cells, each one of which is actually a battery in its own right, so really, your car battery is 6 batteries in one. Each cell is made up of a series of lead plates which are sitting in a bath of sulfuric acid (previously known as sulphuric acid). There are two different types of lead plates in each cell; plain lead plates alternate with lead plates coated with lead dioxide. The plain lead plates act as a cathode, the coated lead plates are an anode and the sulfuric acid is an electrolyte. Without going into too much detail, this combination of materials allows a chemical reaction to occur which releases electrons, and these electrons flow to create an electric current which powers your car.

The presence of the lead plates accounts for the extraordinary weight of a car battery, and the sulfuric acid means that a battery must never be tipped over and needs to be handled with care (and rubber gloves). The combination of heavy metal and corrosive acid makes disposal of used batteries a potential environmental nightmare, although the lead can be recycled by specialists. If you have a car battery for disposal, it needs to be taken to an approved recycling centre where it can be handled correctly.


For hassle-free access to one of the UK’s largest networks of van and car maintenance specialists, we just need you to give us a little information. We cover all parts of the UK, so first of all tell us your post code, and then pick the nearest location from the list that you will see. We need to know a bit about your vehicle and what the problem is, and before you know it, you will see all your local garages and mobile mechanics, their distance from you and their contact details. You now have a choice – call a garage direct to discuss your battery problems or ask for a no-obligation quote (free of charge). It’s as simple as that.

An unreliable vehicle is guaranteed to let you down at the most inconvenient of times – you really do need your car to start first time. You don’t need to waste valuable time doing online search after search to get the best prices on car repairs; simply get one of our industry-approved and trusted network members to give your car a thorough check-up. They can be relied upon to provide a quick and cost-effective repair and maintenance service, including replacing your battery if it’s really necessary, and then starting your car is one less thing for you to worry about.