Car Battery Chargers Buyers Guide

If you have a car in storage for the winter, or your car just won't start, you might need the help of a battery charger!

Car battery chargers plug into your mains electricity socket and attach to the terminals of your car battery. They can be used to charge up a battery that has run low, or to maintain a car battery that isn't being used - for example, if you leave your car in storage over the winter.

If you want to know how to charge your car battery, take a look at our guide.

What do they do?

All chargers send electricity to your car's battery, but there are three main functions that they can perform. Make sure that the charger you buy can do what you need it to!

  • Maintenance charging - Also called 'trickle' charging, this sends a small amount of electricity to your battery to keep it healthy while it's being stored for long periods of time.
  • Conventional charging - This sends power to your battery to charge it up from a low amount of power. It takes between 6-24 hours, but normally about 10 hours to charge a battery from empty to full.
  • Engine start function - This is the same as jump starting your car. It takes a lot more power, so is normally seen on more heavy duty chargers.

Smart chargers

Smart chargers can be used for both charging your battery and long term connection for maintenance charging. They'll automatically detect the fastest charging mode, and will switch to a trickle charge when the battery is full - so there's no risk of over-charging and damaging your battery!

Which one do I need?

If you know what sort of charging you want to do, there are just a couple of things to think about when picking a battery charger:

  • Engine size - How big is your engine? A bigger engine needs a bigger battery, which in turn needs a more powerful charger! Check that your charger is suitable for the size of your engine.
  • Battery type - What kind of battery have you got? Lead acid batteries work with all kinds of battery charger as long as they're suitable, but if you have a gel or calcium battery, or an AGM/EFB normally found in cars with stop/start functions.

So, there you have it - a quick guide to Car battery chargers. Make sure that the charger is right for the job that you want, and that it's compatible with your battery, and you're good to go! Head over to our range for more information, or see if we’ve answered your question in our FAQ’s below.

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Car Battery Charger FAQ’s

What is the best car battery charger?

The best car battery charger is a charger that is powerful enough to handle your engine size and compatible with your type of battery. These are the two key factors to keep in mind when buying!

Which car battery charger do I need for my van?

Look out for a heavy duty car battery charger for your van. You may find the right product is listed as servicing your engine size (i.e. 2.0L), or that it’s listed as being a suitable charger for 12 or 24V batteries.

At what amp should I charge my car battery?

48 amp hours is the average capacity of a standard car battery, while the charging speed of a typical charger is roughly 2 amps. From knowing these two figures, you can calculate exactly how long you should be charging your car battery for.

If your battery capacity and charging speeds are 48 and 2 respectively, it will take you 24 hours to charge a battery that is completely flat, to full. Similarly, if your capacity is 60 amp hours and your charger operates at 3 amps, you’ll need 20 hours to charge your battery from flat to full.

Can I use a motorcycle battery charger on a car?

Be extremely cautious when looking to charge your motorcycle battery with a car battery charger. When batteries are overcharged, they lose their capacity to hold electricity, and so pay close attention to the capacity of your motorcycle battery and the charging speed of a car battery charger when looking to use them together.

That said, most motorcycle batteries are compatible with the USB connectors you’ll typically find on car batteries, so you should be ok to use them if they seem appropriate for your motorcycle’s engine size.

How to repair a car battery charger?

Car battery chargers rarely break given they have no moving parts, but if you do find they break- we recommend bringing your charger into your local Halfords’ store for assistance.

We do not advise tampering with your car battery charger unless you’re a qualified electrician as the internal wirings you’ll find inside your charger are not designed to be DIY serviceable.

That said, the most likely cause of a breakage is a blown fuse, and a voltmeter could help to identify whether a charger is actually producing electricity when plugged into the mains. If a charger is producing over 12 volts, it’s probably OK- however if it’s producing below this amount, a blown fuse is most likely the root of the problem.

Can you leave a car battery charger on for too long?

Yes! Smart chargers will pop themselves into maintenance mode to avoid overcharging your battery, however traditional chargers are not capable of this- so be careful not to overcharge your batteries as this could reduce their capacity to hold electricity.

Can I jump start my car with a battery charger?

No. A car battery charger typically won’t produce enough electricity to allow you to jump start your car- they’re designed to deliver small amounts of charge over a long period of time.

Where can I buy a car battery charger?

You can purchase a charger from your local Halfords’ store- or browse our full range of chargers here.