Peugeot 308 II 12V Battery and Jump Starting

Hello and welcome. In this article we look at the 12 V battery on the Peugeot 308 II (2015-present): reaching it, jump starting the engine, charging it with a battery charger, and disconnecting and reconnecting it. Some details depend on your car's version or equipment.

Quick Reference

Lead-acid starter batteries

This section covers starting the engine using another battery and charging a flat battery. Lead-acid batteries contain harmful substances, sulphuric acid and lead, so they must be disposed of in line with regulations. Never throw them away with household waste. Take used remote control batteries and vehicle batteries to a special collection point.

Before you handle the battery, follow these safety points:

• Protect your eyes and face.
• Work in a well ventilated area, away from naked flames and anything that could cause sparks, to avoid any risk of explosion or fire.
• Wash your hands when you have finished.

Versions with Stop & Start have a 12 V lead-acid battery with special technology and specifications. Only a PEUGEOT dealer or a qualified workshop should replace it.

Before you do any work on the battery:

1. Immobilise the car: apply the parking brake, put the gearbox in neutral, then switch off the ignition.
2. Check the electrics: make sure all electrical equipment is switched off.

Symbols

The battery carries several warning symbols. Here is what they mean:

• No sparks or naked flames, and no smoking.
• Always protect your eyes. Explosive gases can cause blindness and injury.
• Keep the battery out of the reach of children.
• The battery contains sulphuric acid, which can cause blindness or severe burns.
• Refer to the handbook for more information.
• Explosive gases can be present close to the battery.

Access to the battery

The battery is located under the bonnet. To reach it:

1. Open the bonnet: pull the interior release lever, then release the exterior safety catch.
2. Secure the bonnet: fix the bonnet stay in place.
3. Uncover the terminal: remove the plastic cover on the (+) terminal.

You cannot reach the battery (-) terminal. Instead, there is a remote earth point on the engine.

Starting using another battery

If your battery is flat, you can start the engine using a backup battery, either a separate one or one in another vehicle, with jump leads. You can also use a battery booster.

Before you start, follow these safety rules:

• Never start the engine by connecting a battery charger.
• Never use a battery booster of 24 V or higher.
• Check that the backup battery has a nominal voltage of 12 V and a capacity at least equal to that of the flat battery.
• Make sure the two vehicles are not touching each other.
• Switch off everything that uses electricity on both vehicles, such as the audio system, wipers and lighting.
• Keep the jump leads well away from the engine's moving parts, such as the fan and belt.
• Do not disconnect the (+) terminal while the engine is running.

Then follow these steps:

1. Uncover the terminal: lift the plastic cover on the (+) terminal, if your car has one.
2. Red lead: connect the red lead to the (+) terminal of flat battery A, at the metal elbow, then to the (+) terminal of backup battery B or of the booster.
3. Green or black lead, first end: connect one end to the (-) terminal of backup battery B or of the booster, or to an earth point on the assisting vehicle.
4. Green or black lead, second end: connect the other end to earth point C on your car.
5. Start the assisting vehicle: start its engine and leave it running for a few minutes.
6. Start your car: operate the starter and let the engine run. If it does not start straight away, switch off the ignition and wait a few moments before trying again.
7. Let it settle: wait for the engine to return to idle.
8. Remove the leads: disconnect the jump leads in reverse order.
9. Refit the cover: put the plastic cover back on the (+) terminal, if your car has one.
10. Recharge the battery: let the engine run for at least 30 minutes with the car stationary, so the battery reaches an adequate state of charge.

Drive carefully for the first 30 minutes after starting the engine. If your car has an automatic gearbox, never try to start it by pushing.

Charging the battery using a battery charger

Keeping the battery well charged gives it the longest possible service life. You may need to charge it if you mainly use the car for short journeys, or if the car will be off the road for several weeks. Contact a PEUGEOT dealer or a qualified workshop for advice.

Always follow the charger manufacturer's instructions and never reverse the polarities. You do not need to disconnect the battery.

1. Ignition: switch the ignition off.
2. Electrics: switch off all electrical consumers, such as the audio system, lighting and wipers.
3. Charger off: switch off charger B before connecting its cables to the battery, to avoid dangerous sparks.
4. Check the cables: make sure the charger cables are in good condition.
5. Uncover the terminal: lift the plastic cover on the (+) terminal, if your car has one.
6. Red cable: connect the positive (+) red cable of charger B to the (+) terminal of battery A.
7. Black cable: connect the negative (-) black cable to earth point C on the car.
8. When charging is finished: switch off charger B before disconnecting the cables from battery A.

If your car carries the 12 V charger label, use only a 12 V charger. Otherwise you could cause irreversible damage to the electrical components connected to the Stop & Start system.

Never try to charge a frozen battery, as there is a risk of explosion. If the battery has frozen, have it checked by a PEUGEOT dealer or a qualified workshop. They will make sure the internal components are not damaged and the case has not cracked, as a cracked case could leak toxic and corrosive acid.

Stop & Start may not work during the trip after the first engine start. In this case, it only becomes available again after the car has been parked continuously for a period that depends on the outside temperature and the battery's state of charge (up to about 8 hours).

Disconnecting the battery

If your car will be out of use for a long period, disconnect the battery so it keeps enough charge to start the engine.

Before disconnecting the battery:

1. Close everything: close all doors, the boot, the windows and the roof.
2. Electrics: switch off all electrical consumers, such as the audio system, wipers and lighting.
3. Ignition: switch off the ignition and wait for 4 minutes.

You only need to disconnect the (+) terminal, which has a quick-release terminal clamp.

Disconnecting the (+) terminal:

1. Cover: depending on equipment, lift the plastic cover on the (+) terminal.
2. Release: raise lever A fully to release clamp B.
3. Remove: lift clamp B off the terminal.

Reconnecting the (+) terminal:

1. Lever up: raise lever A fully.
2. Position: refit the open clamp B on the (+) terminal.
3. Press down: push clamp B fully down.
4. Lock: lower lever A to lock clamp B.
5. Cover: depending on equipment, lower the plastic cover on the (+) terminal.

Do not force the lever. It will not lock if the clamp is not positioned correctly, so start the procedure again.

After reconnecting: switch on the ignition and wait 1 minute before starting the engine, so the electronic systems can initialise. If minor problems persist after this, contact a PEUGEOT dealer or a qualified workshop.

After reconnecting the battery, reset this equipment:

• Remote control key.
• Electric blind.
• Electric windows.
• Date and time.
• Preset radio stations.

Frequently Asked Questions

Where is the battery on a Peugeot 308?

The battery is under the bonnet. You cannot reach the (-) terminal, so use the remote earth point on the engine instead.

How long should I run my Peugeot 308 after a jump start?

Let the engine run for at least 30 minutes with the car stationary so the battery reaches an adequate state of charge. Drive carefully for the first 30 minutes after starting.

Can I push start a Peugeot 308 automatic?

No. With an automatic gearbox, never try to start the engine by pushing the car.

Why is Stop & Start not working after charging the battery?

Stop & Start may not work during the trip after the first engine start. It becomes available again after the car has been parked continuously for a period that depends on the outside temperature and the battery's charge (up to about 8 hours).

A flat battery is easy to deal with once you know the right order for connecting the leads and the safety rules to follow. Protect your eyes, keep sparks away and take your time, and your 308 will be back on the road quickly. If anything seems wrong, contact a PEUGEOT dealer or a qualified workshop.

More Peugeot 308 Guides

If a battery or charging warning appears on your dashboard, see our guides to Peugeot 308 red warning lights and Peugeot 308 orange warning lights.

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This is an independent guide, not an official Peugeot publication. Check your vehicle’s own manual before carrying out any work.

Related guides: Peugeot 308 model guides.

Cover adapted from a photograph by RL GNZLZ from Chile — Wikimedia Commons, CC BY-SA 2.0 (AI edited).