Peugeot 308 SW T7 - ODB to USB drain power from battery

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bulkier
Donor 2024
Posts: 25
Joined: 03 May 2024, 20:28
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Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by bulkier »

Hi,

I bought "Multifunctional Dual Port OBD Charger Single Port Output 5V"

https://www.aliexpress.com/item/1005004 ... 1802ZyVRoH

so I can have a USB port for charging my phone.

But if I leave this adapter plugged in ODB port for three days, without starting engine, it will drain my battery!!

How this is possible? Is it fault of this ODB adapter or something wrong is with my car?

(I use same adapter on previous Peugeot 308 SW T7 2010 and I never had this problem!)

Is there any other way to get USB port for charging phone except lighter port?

Thanks
wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by wheeler »

It really depends on how its wired up inside, sounds like it may be connected to the permanent 12v power, does it charge your phone even when the engine is off?
If it were me i'd personally avoid something like this in the OBD socket.
If you dont want to use the 12v socket you really want to hard wire & you can use a piggy back fuse if you dont want to butcher original wiring.
plenty of options like this > https://www.aliexpress.com/w/wholesale- ... t.search.0
PopPops
Posts: 29
Joined: 12 Jul 2011, 12:11
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Re: Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by PopPops »

bulkier wrote: 26 Jun 2024, 23:16 Hi,

I bought "Multifunctional Dual Port OBD Charger Single Port Output 5V"

https://www.aliexpress.com/item/1005004 ... 1802ZyVRoH

so I can have a USB port for charging my phone.

But if I leave this adapter plugged in ODB port for three days, without starting engine, it will drain my battery!!

How this is possible? Is it fault of this ODB adapter or something wrong is with my car?

(I use same adapter on previous Peugeot 308 SW T7 2010 and I never had this problem!)

Is there any other way to get USB port for charging phone except lighter port?

Thanks
There is nothing wrong with your car. The OBD port has a permanently live 12v, which, depending on your application, may be a good thing, or not.

To drain your battery in 3 days, assuming your battery is good, the adapter must be drawing a constant approximately 1 Amp, which may be what the adapter does, but, it sounds like poor electrical design to me. 72 hours x 1 Amp = 72Ah, around the capacity of your battery.

As you have used the same adapter before, maybe your battery is weak, or the adapter has developed a fault.

Personally, I would never leave anything connected to a permanent supply.
Nigel
bulkier
Donor 2024
Posts: 25
Joined: 03 May 2024, 20:28
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Re: Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by bulkier »

wheeler wrote: 27 Jun 2024, 09:27 It really depends on how its wired up inside, sounds like it may be connected to the permanent 12v power, does it charge your phone even when the engine is off?
If it were me i'd personally avoid something like this in the OBD socket.
If you dont want to use the 12v socket you really want to hard wire & you can use a piggy back fuse if you dont want to butcher original wiring.
plenty of options like this > https://www.aliexpress.com/w/wholesale- ... t.search.0
Thank you for answer!

Where would be the best place to connect this 12v to 5v converter, to which 12v wire? I would like to be somewhere behind radio (central console). Not sure if I can find 12v socket (lighter) wire there? I think it would be the best option…? - Lighter (12v port) is without current if car is turned off?

Btw
What is “ piggy back fuse”?
bulkier
Donor 2024
Posts: 25
Joined: 03 May 2024, 20:28
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Re: Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by bulkier »

PopPops wrote: 27 Jun 2024, 12:45 There is nothing wrong with your car. The OBD port has a permanently live 12v, which, depending on your application, may be a good thing, or not.

To drain your battery in 3 days, assuming your battery is good, the adapter must be drawing a constant approximately 1 Amp, which may be what the adapter does, but, it sounds like poor electrical design to me. 72 hours x 1 Amp = 72Ah, around the capacity of your battery.

As you have used the same adapter before, maybe your battery is weak, or the adapter has developed a fault.

Personally, I would never leave anything connected to a permanent supply.
Thanks for answer!

Yes, for sure this is “always on” 12v on OBD since i can see green light on phone charger even if car is turned off for hours!

I will try to measure current on ODB to USB adapter.

Btw battery is the same as in the old car, I switch them :)
wheeler
Posts: 7004
Joined: 21 Sep 2002, 19:07
x 767

Re: Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by wheeler »

bulkier wrote: 27 Jun 2024, 23:28 Btw
What is “ piggy back fuse”?
https://www.aliexpress.com/item/3281605 ... ry_from%3A

They dont look great but saves butchering original wiring.
bulkier
Donor 2024
Posts: 25
Joined: 03 May 2024, 20:28
x 1

Re: Peugeot 308 SW T7 - ODB to USB drain power from battery

Post by bulkier »

wheeler wrote: 28 Jun 2024, 07:59 https://www.aliexpress.com/item/3281605 ... ry_from%3A

They dont look great but saves butchering original wiring.
ah, I see! It is nice solution but in my case I would need to pull wire from fuse box on the left, under the wheel and then to the main, central, console.