battery current draw when ignition off?

[swissrob]

hi all,

does any know what the normal current draw is from the battery with the ignition switched off, and after the time period for the canbus power to the acessory socket to switch off????

a mates bike battery keeps going flat - in the process to troubleshooting and later will measure the draw

 

[F104]

hi all,

does any know what the normal current draw is from the battery with the ignition switched off, and after the time period for the canbus power to the acessory socket to switch off????

a mates bike battery keeps going flat - in the process to troubleshooting and later will measure the draw

on bmw cars it should be in 20-30 mAmp range, 40 max (I had issues on my car, these values are from BMW head office belgium). I would think without alarm you want to see 20 or less, with alarm 30 max. PS not easy to measure this

 

[Metisse]

hi all,

does any know what the normal current draw is from the battery with the ignition switched off, and after the time period for the CanBus power to the accessory socket to switch off????

a mates bike battery keeps going flat - in the process to troubleshooting and later will measure the draw

I had a problem when I first got my GSA in 2006. I had a phone charger connected to the accessory socket (12v - 5v USB) and my battery kept discharging. Vines couldn't trace why the battery was draining but did find that the CanBus wasn't shutting down. There is a drain as F104 says but can't remember how much - 20mA seems familiar

I removed the charger and it stopped. I'm not sure but it seemed that if something drawing only a tiny current was connected to the accessory socket the CanBus failed to shut down and the battery drained. Removed it, all OK CanBus shuts down, put a large drain on it i.e. a lamp, CanBus shuts down OK but put a very small drain and the CanBus fails to close allowing the battery to drain overnight.

I'm not sure if the ECU thought something was connected that the CanBus should stay on for e.g. a BMW charger??

Just a thought - my stuff is all separately powered now.

Peter

 

[F104]

there will be a drain as at least the clock runs. The issue is indeed if you have hooked something up that keeps the can bus alive, instead of going to sleep.
With the can bus alive there will be a significant drain. On my car the ECU would talk to an aftermarket OBD reader for up to 30 minutes after shutdown, before giving up - drawing 4 Amp all the time. Issue was resolved by the OBD reader manufacturer, it implemented a shut down option after seeing 0 rpm, and yup the ECU shuts down too 30 seconds after the OBD reader

 

[ExpatinIstanbul]

Leaving myself open for derision, I was told that if turning the ignition on, then turning it off without starting the bike, the computer keeps going through the starting sequence.

 

[ciderman gs]

it is in the ecu bmw have programmed the battery to go flat if you don't use it and the rac and aa are in partnership with the programmers

 

[freeloader]

If he has a satnav attached to the dedicated connector, that could be the reason for a high current draw.

Happened to me (an F800GS, not an R1200GS, but the suggestion stands); when I connected my Zumo 550's cradle to the dedicated socket, my battery kept going flat too. Apparently even the empty cradle draws enough power to fool the ECU into not realising the ignition has been turned off, in some cases.

I rewired the power supply via a relay triggered from the accessory socket, and haven't had battery problems since.

 

[swissrob]

If he has a satnav attached to the dedicated connector, that could be the reason for a high current draw.

Happened to me (an F800GS, not an R1200GS, but the suggestion stands); when I connected my Zumo 550's cradle to the dedicated socket, my battery kept going flat too. Apparently even the empty cradle draws enough power to fool the ECU into not realising the ignition has been turned off, in some cases.

I rewired the power supply via a relay triggered from the accessory socket, and haven't had battery problems since.

mm he has a zumo cradle... could well be a starting point.

ta 4 the replies

 

[NLC]

If he has a satnav attached to the dedicated connector, that could be the reason for a high current draw.

Happened to me (an F800GS, not an R1200GS, but the suggestion stands); when I connected my Zumo 550's cradle to the dedicated socket, my battery kept going flat too. Apparently even the empty cradle draws enough power to fool the ECU into not realising the ignition has been turned off, in some cases.

I rewired the power supply via a relay triggered from the accessory socket, and haven't had battery problems since.

+1. I have a Zumo 660 and if the Zumo is not charged it will keep everything on the bike until the Zumo charges itself. SWMBO was wondering why the garage looked like God was arriving an hour after I got home (aux spots kept on).

 

[freeloader]

If he has a satnav attached to the dedicated connector, that could be the reason for a high current draw.

Happened to me (an F800GS, not an R1200GS, but the suggestion stands); when I connected my Zumo 550's cradle to the dedicated socket, my battery kept going flat too. Apparently even the empty cradle draws enough power to fool the ECU into not realising the ignition has been turned off, in some cases.

I rewired the power supply via a relay triggered from the accessory socket, and haven't had battery problems since.

mm he has a zumo cradle... could well be a starting point.

ta 4 the replies

Just to underline the point, I was speaking to the owner of an R1200RT today who has the BMW-branded Zumo 550 on his bike - and his battery goes flat when it shouldn't. It's currently (ho ho) being investigated by BMW.

My relay-based solution means the Zumo cradle switches off when the accessory socket does, since the bike can't actually "talk" to the Zumo cradle; it's just a dumb connection.

 

[swissrob]

i will have a look with a multimeter and see the current draw with the cradle on/off

 

[cookie]

Leaving myself open for derision, I was told that if turning the ignition on, then turning it off without starting the bike, the computer keeps going through the starting sequence.

that was the case, but it was fixed in a software update some time ago.

 

[TeaPig]

The drain is about 30mA for a few seconds after the ignition is turned off after which it ought to then go down to close to zero.

If the drain is significantly higher there's either an accessory connected or the power distribution section of the ECU has been fried. Using crude battery chargers via the accessory socket can do this, but you would have to be quite unlucky

 

[swissrob]

got it sorted ... as said above current draw is about 30ma for approx 30 secs then it goes to zero, my meter reads 0.000 so any draw for the clock is below that.

In the end we found it was a relay for aftermarket spotlights, the relay had become waterlogged and the coil was constantly energised pulling a constant 150ma

 

[freeloader]

Well done - that's a new one to me. I've always done my best to mount any extra electrical stuff where the weather has the least chance of finding it, and been lucky so far...