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edd_jedi

OBD2 Port Draining Battery

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I have bought an aftermarket HUD which plugs in to the OBD2 port, mainly because the E60 has no water temperature gauge and I want to see it. It works great, but it is draining my battery when the car is locked. The HUD itself seems to power off, but for some reason the cable still drains power if left plugged in.

 

I could just unplug the cable each time I get out the car, but it’s a bit of a pain and I might forget. Does anybody know why the OBD port draws power without the blanking plug connected? I have noticed it has some pins in it, maybe they tell it to switch off? Am wondering if there’s a way I can modify it to leave the HUD cable plugged in.

 

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Edited by edd_jedi

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The only way is to look at the WDS find the live feed pin, run a new live wire to a switched accessory feed, i would look for you on WDS but i cant access it from work computer

 

Nice hud by the way

Edited by Misterbish

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If it has a switch then i suppose so yes, the Carly OBD dongle has a on/off switch and when switch off and left in the port it doesn't drain the battery.

 

Where did you get your hud from

Edited by Misterbish

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I got this one:

 

https://www.amazon.co.uk/gp/product/B072DZLGXL/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

 

Although it's saying sold out now. You can get it on eBay but only from Chinese sellers, which is why I paid a bit more to buy from Amazon and get it quicker. It's a decent piece of kit, just need to solve the battery drain.

Edited by edd_jedi

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3 minutes ago, edd_jedi said:

I got this one:

 

https://www.amazon.co.uk/gp/product/B072DZLGXL/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

 

Although it's saying sold out now. You can get it on eBay but only from Chinese sellers, which is why I paid a bit more to buy from Amazon and get it quicker. It's as decent piece of kit, just need to solve the battery drain.

 

https://www.ebay.co.uk/itm/5-5-A8-Car-HUD-Head-Up-Display-OBD2-Compass-Speedometer-Speeding-Warning-UK/141950969387?epid=15006620598&hash=item210cefe62b:g:IDUAAOSwSX9XBKhU

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It says UK, but if you look at the sellers address it is from China. Sadly eBay can't stop foreign sellers listing items as based in the UK. That means it will likely take at least a week to arrive, and as it costs over £15GBP will be liable to customs duty.

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7 hours ago, edd_jedi said:

It says UK, but if you look at the sellers address it is from China. Sadly eBay can't stop foreign sellers listing items as based in the UK. That means it will likely take at least a week to arrive, and as it costs over £15GBP will be liable to customs duty.

 

Hmmm, I've ordered stuff from China before well over the £15 limit and not yet had a customs surcharge, so I'll probably risk it once I've done some more important stuff to my car :)

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(Q1) Was the battery drain issue solved? Was the battery drain definitely due to the ODBII /HUD cable connection?

 

The poduct info claims the ODBII HUD to:

Quote

Auto power on and off with the vehicle.

see PDF instruction manual here.

 

(Q2) Is your foot ever likely to catch the ODBC plug when getting in/out the car?
(Q3) Is any of the design left hand drive orientated and does that compromise in anyway (cabling, buttons and display orientation etc.).
(Q4) How have you rooted the cable? (maybe post some pics including your preferred mounting position)

Edit: (Q5) Do you see a double image on an E60 laminated windscreen?

 

Fuel is in Litres/Hour, no MPG. The display looks a little busy at night, I'd probably mask off some of the less useful bright information (with black tape).

Looks a pretty cheap geeky toy (for me) to play with if nothing else.

 

 

Edited by DarkHorse
typo's

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1) Yes it is definitely the HUD and/or OBD2 cable causing the drain, even though the device does power off as per the instructions a drain is still occuring. Only solution so far is physically disconncting the cable from the OBD2 port.

2) Not so far, unfortunately the plug isn't quite small enough to close the cover with it plugged in but it doesn't get in the way.

3) The buttons and cable port are on the left hand side of the device. It would have been better if the port was on the rear, then it would exit towards the windscreen for either orientation.

4) The cable is flat so it easily tucks in along the trim gaps, apart from the end USB plug and OBD2 plug you cannot see the cable at all.

5) Yes you see a double image without using the included reflective film.

 

Yes it would be nice if you could change L/H to MPG, but that's my only real niggle (apart from the battery drain obviously.) Really can't complain for the price.

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Thanks for the update, info and the daylight image B).

 

Strange about the battery drain, wondering if OBD2 has various versions depending on the age and firmware version. Hopefully someone will come up with a solution soon.

 

 

Edit: Only found these so far:

 

...read one review for one available on amazon, they say the power drain depends on the car... some cars don't supply OBD power unless activated.

http://www.mycarforum.com/topic/2699154-obdaftermarket-hud-heads-up-display/

 


2. Fortunately our 2013 Subaru Outback isn't one of the cars that maintains power to the OBD-II connector when the ignition is off. If you're not so lucky, the manufacturer suggests disconnecting the OBD-II cable every time you turn off the ignition, lest you drain the battery. First, you're likely to forget; second, the OBD-II connector may be buried far under the dash; third, you're apt to wear out the OBD-II connector, which wasn't designed to be plugged and unplugged thousands of times. Why not at least provide an on/off switch, if not a "sleep" mode?

 

...At least for my car leaving this plugged in did not noticeably drain the battery, at least not after the four days that is the longest it has been idle. I was initially a bit concerned about that because the little interface box has a tiny blue LED blink occasionally while the car was completely off, and they warn that some cars leave the OBD-II port powered up while off.

https://www.amazon.com/OBD-II-Display-Speedometer-Voltage-installation/product-reviews/B007PX8476

 

Edited by DarkHorse
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Any more info on the ODBII port staying active and draining the battery?

At what rate does it consume power when the HUD is connected and shutdown/sleeping?

 

Anyway, I'd like to know the details because my HUD arrived yesturday B) (£20 delivered 8 days later). I looked at a few and decided that I wanted to go for a less cluttered, less distracting minimalist data view, although it doesn't look quite as impressive as a result. I specifically fleebay ordered one advertised in the darker display colours green/purple (like this one) but the more common yellow/pink colour version arrived :angry:.

The RPM does appear visually to have less resolution (500rpm/block on HUD) but the numbers and dashes fill in every other 250 rpm (effectively  the same then). Also I wanted the RPM to arc with the same visual orientation as the real RPM dial, as I didn't like the RPM to start under the speed number.

The cable connects to the rear of this unit.

20180511_070215.thumb.jpg.fd2754ccd00f1ad4590fce32d2df81da.jpg20180511_070348.thumb.jpg.2527c8fc21d1cd4780c93ba8262e5625.jpg20180511_072909.thumb.jpg.05fccf1010e37b374d6e7c44ac7183d5.jpg

 

Not yet used the supplied stickey pad, just added a strip of double sided sticky tape along the front endge of the device.

Not using reflective screen so I will live with the double vision. See one here https://youtu.be/Fu6e_Q0pyEI?t=289 (nice Mustang!) and also saw a possible alternative reflective idea here https://www.youtube.com/watch?v=iQ_P72bIxuE&feature=youtu.be&t=370
 

I do find the reflections of the numbers even when not lit are quite visible in day light (see images above), so I'm road testing a DIY blue plastic film tint overlay (craft shop stuff, like sweet wrapping), see images below. The reflections are reduced but the daytime visibility is reduced, should look a bit better at night though.

 

20180511_171118.thumb.jpg.00a05a8fefdfd5fb30397433a00cdef2.jpg20180511_171234.thumb.jpg.684f123c48fb67efb8d81547097e8cde.jpg

 

The HUD data scan update rate is about every 1/2 second at best.

 

Speedo Accuracy:
10mph speedo = 8mph HUD
25mph to 60mph = same on HUD
80mph speedo = 82mph HUD

 

RPM seems accurate enough but being a more dymanic faster changeable value, it is more laggy due to limited scan update rate.

 

Temperature , I saw a range 96C to 100C urban cruising. No accuracy confirmation yet. Useful to know on an E60/E61 and probably one of the main reasons for getting the bloody thing :lol:. Would have been nice to also monitor other tings like oil temp/pressure.

 

Voltage monitor seems to work fine. My battery is a bit old 12.4v, 14.4 charging.

 

Fuel calcs:

L/H is a bit of a meaningless instantanious number:
L/H value/4.54 = Gal/H then mph/(Gal/H) = MPG, To do this calculation on the fly in your head, relative to MPH is pretty hard, so it's L/H is a pretty pointless reference.
End of journey the HUD reports 13.8 L/100km = 20.5 MPG (urban 11 mile runs)
The iDrive reports ~24.5 MPG long term average.

 

Intersting 530i petrol observation: When sat stationary (at lights), idling throughout (at 650rpm), the L/H reading is 1.6L/H in gear with foot on clutch, drop into neutral and the reading drops to ~1.1L/H. As soon as I touch the clutch and select a gear the reading instantly goes back to 1.6L/H, so the engine primes the mixture for action in gear idling (maintaining the same 650rpm). A similar jump in consumption to 1.6L/H also occurs when switching on the AC. 

 


 

Not tested for power drain, currently port unplugging.

 

What is the OBDII cover resister for?

Found this:
- And what happens if you forget to shut the cover.

- I forgot to close mine once, I felt no difference and I received no error message etc. Strange isn't it!

- The resistor is there to "complete" a bus circuit for diagnostics when the factory tool is connected to the round 20-pin connector under the hood.
Therefore, the OBD2 cover must be closed when using the 20-pin OBD connector.

 

 

 

 

Edited by DarkHorse
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Nice review of yours! I haven't tried leaving it plugged in again as I don't want to ruin my nearly new battery, but it went from full to flat in at most 2 days, possibly sooner. I did get this response from Amazon customer services but haven't tried it yet:

 

Quote

First,If the machine is not turned off when the car not working, it will certainly consume power and impact on the car battery. 
Second, the machine can not automatically shut down are related to the voltage of the car, please kindly set it base on the  user manua automatically. 
Or you can set follow below instructions:
1.Press and hold the wheel key for 5 seconds vertically to enter the setting item. 
2.Short press 15 times to enter 15 items check if the default value is 132. 
3.If it does not turn off automatically, turn this value up to 135 or 138, then long press the wheel key for  5 Seconds to save ,wait within 3 minutes it will automatically shut down.

 

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Ah, yes the default is supposed to be 132 according to the manual but mine was set to 0. Before changing this value the unit would not shut down when the engine was switched off. Now the unit waits 10 seconds whilst displaying the calculated average for L/100km value then the display goes completely blank (like this one does).

For start up, insert the key, nothing happens on the unit until the engine is started and the alternator raises the voltage, then the unit begins to start up, a few seconds later the telemetry starts.

Is this how your unit behaves or does the display stay lit up as the voltage detection parameter is set too low? This could explain your initial observations regarding the battery drain.

 

 

 

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OK thanks, no mine does appear to visibly shut down so I don't think this will solve it. I have found OBD2 extension cables with inline power switches on eBay, was considering trying that.

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I bought one of these, it is very well made and would do a good job, but unfortunately there is no flat surface far enough away from the windscreen with room to open to reflective panel on the E60 dashboard :( so looks like I'm going to have to stick with the windscreen film.

 

hud.thumb.jpg.e6a118b1dc3bd7479fed65c8c4d84f05.jpg

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On 5/12/2018 at 5:59 PM, edd_jedi said:

OK thanks, no mine does appear to visibly shut down so I don't think this will solve it. I have found OBD2 extension cables with inline power switches on eBay, was considering trying that.

Me being me I would fit a relay triggered by the ciggy socket to power it down when the engines shut off, saves having to remember doing anything when you get out.

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7 minutes ago, GoNz0 said:

Me being me I would fit a relay triggered by the ciggy socket to power it down when the engines shut off, saves having to remember doing anything when you get out.

 

This would be the best solution.

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2 hours ago, Mashed Potatoes said:

 

This would be the best solution.

Given me an idea now to cut the signal wires on the ODB with a 2 channel relay, under £4 as well :)

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