What is your engine designation number. You get this from the VIN, start with "V", count to 6,7,8 and provide these three letters or numbers.

 

In addition to RedSector's question can I ask where you measured the 14.8 to 14.9V- was it between the battery terminals? If so can you repeat the measurement with the black probe on some bare metal instead of the negative terminal.

Can you also have a look at your stop-start controller and let me know if it looks like the one below:

EDIT
One other question- is the stop-start system working? They usually take 24 hours to work after a battery change.

 

Thanks guys I will get back too you later today with the answers the voltage was measured from the ECU at the alternator and battery with a lexia diagnostic and a multimeter at the battery. I will try it on the block later when I get home.

The start stop was working just fine then we had a very cold night in January and when I started the car in the morning it just stopped working and has not worked since.

I had tried getting to the controller a few months ago but gave up as I simply don't know how to access it. I have the special tool to remove it I just can't get access too it. I don't know if the wing needs too come off or if there is a special way too do it.

 

I think you may have a reverse alternator. The stop start controller in the photo is used on a euro 6 engine with a standard alternator.

 

Engine is a dv6c engine, it's a 2013 model. I don't have a clue on what a reverse alternator is but I've used a multimeter on the block not showing any short the block is grounded. I'm getting the feeling its the battery sensor on the ground side of the battery. Since removing the battery today and putting the battery back in lexia is now saying the battery is 60% but before I removed the battery it was 74% charged.

I do know the previous owner has remapped the car, not that he told me I only found out when I noticed the car was not doing any regens so when I removed the dpf only to find both the dpf and cat completely gutted, I now own a car that's worth maybe scrap metal and still paying for the car. Never again will I buy from gumtree it's not the first time I've been scammed buying a car. Anyway back too the problem. Any ideas even the garage can't find the problem.

 

You said that your alternator is charging at 14.8 - 14.9v but the battery is not reaching full charge. That voltage should be enough to charge the battery unless the charging system is reducing the alternator output. I am still not sure where you are measuring the voltage. For your purposes the only reliable place is between the battery terminals with the engine running. A small contact resistance can cause a significant voltage drop (e.g. 0.1 Ohm with a 10Amp charge current will cause a 1 Volt drop). The battery should have two earth points (one on the body and the other on the engine/gearbox). If one of these is slightly loose or has some corrosion you will get a voltage drop.

It does seem odd that Diagbox is reporting the battery state of charge dropped when the battery was disconnected. It is important to make sure you have no contact resistance e.g. clean battery terminals and good earth points. If not the battery status unit on the negative terminal may give wrong data.

I have attached the starting diagram for a 5008 with a DV6C engine with a stop-start system. This diagram also covers the charging system. The blocks of interest are:
1012 centralised voltage maintaining system (AKA stop start controller)
1026 energy accumulator (AKA stop-start capacitor)
1021 reversible alternator
1031 battery charge status unit
BB00 battery

This site shows a photo of a Peugeot 208 with part of the left wing removed: Peugeot 208 Stop/Start issues - Car Electrics & Repairs The cylinder in the photo is the stop-start capacitor and the aluminum block next to it is the stop-start controller. Your car will have something similar.

Your car has a standard starter motor which should only start the once after that if the stop-start system is in operation the reverse alternator should start the car. Reverse alternators look a bit like standard alternators but are larger and have more cables connecting to them. This site explains the system New Peugeot 308 features e-HDi micro-hybrid technology; CO2 emissions start from 98 g/km

One issue with reverse alternators is the drive belt. The car most likely has a counter which will monitor the amount of use the belt has had and at some point it will disable the stop-start function until the belt is changed and the counter reset using Diagbox.

 

You said that your alternator is charging at 14.8 - 14.9v but the battery is not reaching full charge. That voltage should be enough to charge the battery unless the charging system is reducing the alternator output. I am still not sure where you are measuring the voltage. For your purposes the only reliable place is between the battery terminals with the engine running. A small contact resistance can cause a significant voltage drop (e.g. 0.1 Ohm with a 10Amp charge current will cause a 1 Volt drop). The battery should have two earth points (one on the body and the other on the engine/gearbox). If one of these is slightly loose or has some corrosion you will get a voltage drop.

It does seem odd that Diagbox is reporting the battery state of charge dropped when the battery was disconnected. It is important to make sure you have no contact resistance e.g. clean battery terminals and good earth points. If not the battery status unit on the negative terminal may give wrong data.

I have attached the starting diagram for a 5008 with a DV6C engine with a stop-start system. This diagram also covers the charging system. The blocks of interest are:
1012 centralised voltage maintaining system (AKA stop start controller)
1026 energy accumulator (AKA stop-start capacitor)
1021 reversible alternator
1031 battery charge status unit
BB00 battery

This site shows a photo of a Peugeot 208 with part of the left wing removed: Peugeot 208 Stop/Start issues - Car Electrics & Repairs The cylinder in the photo is the stop-start capacitor and the aluminum block next to it is the stop-start controller. Your car will have something similar.

Your car has a standard starter motor which should only start the once after that if the stop-start system is in operation the reverse alternator should start the car. Reverse alternators look a bit like standard alternators but are larger and have more cables connecting to them. This site explains the system New Peugeot 308 features e-HDi micro-hybrid technology; CO2 emissions start from 98 g/km

One issue with reverse alternators is the drive belt. The car most likely has a counter which will monitor the amount of use the belt has had and at some point it will disable the stop-start function until the belt is changed and the counter reset using Diagbox.

Thank you for the help, I'm not using a diagbox can't afford one I'm using a lexia, the battery was in the car at the time when I checked the voltage with the car running. The reading at both the alternator and battery end which the lexia can show.

Alternator voltage 14.8v
Battery charge voltage 14.7v
When the car is running

When the car is turned off the voltage at the battery is 12.8v

The lexia is also reporting
Permanent Internal fault on energy accumulator and is at 1.9v

When I disconnected the battery I checked ohm from the negative at the battery too the block and body both reporting 0.01 ohm

Look I will be honest I'm not a mechanic and have never used a multimeter before but I have done repairs on all my cars including headgasket replacement and timing belt. I'm just not good with electrical issues.

One last thing when the car reports the battery is above 75% all the faults stop.

The information you have giving is fantastic so thank you I will check the grounding points and see if there is a issue there.

For the accumulator is it easy to get too has anyone done it on the 5008 or 3008 I know it sits behind the side panel but dont have a clue how to get to it. If anyone has a video or instructions to removing the accumulator that would be great

Again thank you everyone for your help.

 

I'm not using a diagbox can't afford one I'm using a lexia

Lexia 3 fullchip (preferred) is the device.
PP2000 and/or Diagbox is an integrated software package for diagnostics (see the two links below). With PP2000 being the older format for use with Lexia, sometimes also called Peugeot Planet (PP from PP2000) and PP2000 generally not usable after 2010 on most model, but this varies. Diagbox (roughly is above 2010 models) is whenever PP2000 does not work or can't read everything or locks up on use.

There is also a version of Diagbox that forms the Factory Service Manual, inclusive of electrical diagrams, but that's another story. Telecoding in some instances may need tokens from Peugeot, but there are versions of Diagabox with some telecoding available and gets complex (another story, not applicable, so far). A lot of this FSM information, telecoding, etc got hidden behind the Great Peugeot Pay wall... can't think of date 2016-2018'ish

Or this is my understanding of things, and taken ages for me to settle on this being even close to correct. YMMV.

Diagbox 9 (VM) install Guide | Peugeot Forums
Non VM version for Windows 10+ (not tested it) Diagbox 9.85 2023 Full » СarSoftos.com

Hope you find this helpful, it's confusing as ~imo.

 

I have attached two Peugeot Servicebox procedures. One is for the battery status unit on the battery negative terminal. The other is for the stop-start capacitor and controller (central voltage retention device). The procedure actually say it can be done without removing the left wing.

I am a bit puzzled by the your diagnostic tool. The Peugeot diagnostic tool is usually called a Lexia 3 and there two alternative software packages Peugeot Planet 2000 (PP2000) and Diagbox. Diagbox replaced PP2000 and there are a lot of free copies

 

All the voltages you listed look good and if you are finding all the accessories such as air-conditioning are working okay I think you can leave things as they are.

It sounds like the stop-start system capacitor has failed. All capacitor age and eventually need replacing. It really a matter of whether you want the stop-start system working. Many people would like to permanently disable the system.

 

All the voltages you listed look good and if you are finding all the accessories such as air-conditioning are working okay I think you can leave things as they are.

It sounds like the stop-start system capacitor has failed. All capacitor age and eventually need replacing. It really a matter of whether you want the stop-start system working. Many people would like to permanently disable the system.

Sorry my mistake I own a Delphi not a lexia. I have very bad brain fog for the past week. Sorry

 

The only fault I'm getting is permanent internal fault recorded accumulator

 

You reported before that"
"The lexia Delphi is also reporting
Permanent Internal fault on energy accumulator and is at 1.9v"

As I explain below I think your stop-start controller is faulty. The stop-start controller also monitors the battery current so may be responsible for the low charge state figure.

I have labeled the accumulator in the photo below from this website Peugeot 208 Stop/Start issues - Car Electrics & Repairs However, I suspect you have exactly the same problem as the 208 discussed on the website. The accumulator is a very large capacitor. When capacitors fail they often still charge up to the full 5V (the amount of energy they hold is reduced) but in your case the charge voltage is only 1.9V which suggests to me the problem is with the controller.

After a bit of searching I found this site Start/stop capacitor Peugeot 3008 - 9802873880 9H05 I have marked up their photo which shows the stop-start system bracket (it's missing the accumulator). There is a long lead which has the battery status unit. All this means that the battery gets its earth via the stop-start controller and its highly likely that both the battery status monitor and the stop-start controller are monitoring the battery current drain

 

If you are going work on the stop-start system you need to be careful with the accumulator. Your diagnostic tool is suggesting it is charged up to 1.5V. That doesn't sound much but these devices can store a lot of energy and if you short circuit you could weld the wires to it. Think of it as a car battery.

There is a procedure to discharge the accumulator. The procedure uses a tool with a meter but you could use a 5W light bulb.