Peugeot 3008 Hybrid battery battery drain

[Dormouse]

Hi. I have been a follower of this forum for a while now and I have taken the plunge and joined up. My car, a Peugeot 3008 Hybrid4 2013, has had a problem with the service (12v) battery running down. It started 3 months ago and the faults that occurred were Air bag/pretensioner dash light came on followed by the amber engine repair required dash warning. I ran Diagbox and got various fault readings:- multiplexed additive pump, FM2 ariel fault and, surprisingly, no air bag faults. A couple of codes referred to low supply voltage. Testing the battery showed a voltage of 11.7. So, charged the battery, cleared the codes and car ran ok. Two days later, same again except this time the red Engine repair dash light came on as well. Tested the service battery - 11.2 v. Ordered a new battery as the battery fitted was the original equipment Fiamm and had the exhaust additive tank topped up as there appeared to be no mention of it in the service history - currently 98500 approx. All was well for about a fortnight then the same problems stated again. I found I could not clear the HCU2 faults which were now appearing and I could no longer get any Gearbox ECU readings. A couple of times the codes said FM2 short circuit to earth, the multilplex additive pump fault still appears and the Airbag warning code refers to the passenger deactivation switch led. The "new" battery was a generic one so I replaced with an Excide Premium - the generic battery was dropping to 12.2v and recovering to 12.4 when disconnected while the new Exide drops to 12.4 and recovers to 12.55. The battery draw is 3.4 amps at first connection dropping to around 2 amps a few minutes in. Where do I start first? thanks in advance

[wheeler]

Firstly does the car have anything electrical fitted that it didnt leave the factory with e.g. handsfree kit, towbar electrics, aftermarket radio?
a 2 amp drain is massive, have you left it at least 10 minutes & rechecked the drain? you need to make sure the car is locked & trick the bonnet into thinking its closed, if the car has a proximity key this also needs to be well out of range.

[Dormouse]

The car has no items added and a dashcam powered in the 12v socket has been removed for tests. I have clicked the bonnet lock down to give bonnet closed signal. I haven't tested the amp draw for as much as 10 mins but I have checked battery voltage recovery over upto 30 mins. I have to 'fess up that I am a retired vehicle restorer, tuner and VOSA trained vehicle examiner. I have only used Diagbox to read and clear codes. I have not used any of the Repair/Maintainance sections as I have been retired for 16 years and my knowledge is sound enough to not allow me to gallop in as I don't have a lot of experience on cars this modern and I would rather learn from more experienced people before I go much further.

[wheeler]

I would just confirm its still drawing too high after at least 20 minutes. Most PSA cars are fully shut down within 5 minutes however hybrids my be different?
Transit vans are around 10 minutes to get full shutdown & some BMW’s are around 20 minutes so best just to confirm.
If its still drawing too high after that then your looking at pulling fuses one at a time to try to narrow it down.

[Dormouse]

Any ideas what the low level residual draw should/could be I can't find any data for it cheers

[Dormouse]

The hybrid system is a 200v battery pack and controller located in the boot. It has cooling fans which draw air in from the front of the rear seat out the vents in the side trim in the boot as far as I can establish. The fans are very quiet but do seem to cut out as you would expect. I have listened for the likes of the EGR sequence after the engine shuts down and it appears normal. Radio, sat nav, interior lights, power sockets, airbag switch and indicator lamps etc all seem to perform properly. I have just started to investigate the aerial and FM2 amplifier but torn ligaments in my knee have put paid to any further crawling about/investigating for the moment but I am reading up everything I can find. Any hints or lines of investigation would be useful. thanks everyone in advance.

[Dormouse]

PS The 200v battery and controller provide the 12v charging for the service battery only when the car is in "Ready" state. It works exactly has you would expect any normal charging to behave - higher voltage at start up for a depleted battery tapering back to a normal maintaining charge level - just as it should be. The 12v service battery does not start the engine, however, it only provides the power for the Body Services. The engine is started by the 200v battery by the belt driven starter/generator

[wheeler]

Any ideas what the low level residual draw should/could be I can't find any data for it cheers

Wouldn’t expect it to be any more than 0.06 amps

[Dormouse]

thanks

[Dormouse]

I have a blog thread about this in "Diagnostics" section if anyone wants more information. cheers.