Can a key left in the ignition, drain battery?

Post by **MjW** » Thu Jul 03, 2014 8:13 pm

Just came back from a month of vacation, went to start the TMax and nada. Dead battery.

Someone told me that leaving the key in the ignition activates the immobiliser which uses battery and that might be the reason for the dead battery. And I did leave the key in the ignition.

Actually I always leave the key in the ignition when I park the TMax in the garage. Saves me the trouble looking for the key.

What do you guys think?

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pikey · Post by **pikey** » Thu Jul 03, 2014 9:09 pm

If its got an immobilizer will come on as soon as scoot turned off whether leave key in or not .When you turn it back on it reads code in key to deactivate immobilizer it maybe that's where confusion lays

Post by **MrGrumpy** » Thu Jul 03, 2014 9:19 pm

Well yes, the immobiliser will be on without the key in (which does drain the current a little). So the only difference leaving the key in could possibly make is NOT enabling the immobiliser.

Your battery is basically knackered - same thing happened to my Tmax mk3, it suddenly died without apparently giving any trouble.

Post by **SH125Paul** » Thu Jul 03, 2014 9:34 pm

wont be covered with your insurance if the worst happens and ya garage is broken in to...

Post by **Funkycowie** » Thu Jul 03, 2014 9:41 pm

You sure you didn't accidentally turn it too far and activate the side/parking lights?

Post by **Hughie** » Thu Jul 03, 2014 11:23 pm

Leaving the key in the off position does nothing.You may just have a suspect battery that died with the non use.The Yamaha system goes into 'zero drain' after 24 hours (or was it 3 days?) if I remember rightly.

Post by **Bluebottle** » Fri Jul 04, 2014 12:36 am

On some vehicles leaving the key in will keep some circuits live even if the ignition is off.
Only removing the key shuts them off ( if it is on a relay you can put the key back in without remaking the circuit)

I would have thought the TMax just had a dumb switch though. (Amps reading with multimeter key in/key out would tell you)

Like everybody says, dodgy battery is first suspect.
But what charge did the battery have when you left? Did you do a lot of little trips that ran your battery down before you left?

Post by **MjW** » Fri Jul 04, 2014 12:39 am

Damn, and it wasn't long ago I changed the battery. I think it was a year or two ago.

I've made a permanent installation of a CTEK charger plug that has an LED that blinks slowly to show how much charge is in the battery. Wonder if it's that, but a blinking led shouldn't be enough to drain the battery.

Funkycowie wrote:You sure you didn't accidentally turn it too far and activate the side/parking lights?

Killed the first battery like that. I've been careful since then and I don't use the key to lock the handlebar while in the garage to accidentally turn on parking lights.

Bluebottle wrote: Like everybody says, dodgy battery is first suspect.
But what charge did the battery have when you left? Did you do a lot of little trips that ran your battery down before you left?

I started riding February with a freshly charged battery and I've been doing mostly short trips, 15-25min, in town with the occasional longer, 1h, ride. Not many long rides though.

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Post by **Data** » Fri Jul 04, 2014 9:57 am

Shame if your battery is now dead after so little time. As has been said, I don't think a key left in the ignition is the problem. Not quite the same but on modern cars as soon as you put the key in the ignition the car detects it and deactivates the immobiliser and also talks to the ecu about other stuff too. In fact, the key, inserted like that with the engine off, is how many modern cars reset the ecu parameters if/when the battery is removed and replaced when the battery has been removed from the vehicle for more that 30 mins (that's if it has a Canbus). Not sure if it's the same on modern scooters. Either way your battery sounds like it's had it's time.

Post by **Cookie** » Fri Jul 04, 2014 10:28 am

Hi MJW,

It could be that CTEK charger plug that you've got permanently installed so don't rule out that possibility.
I don't know what current it draws but even if it's only 15ma it would add up over the month of your vacation...

0.015 x 24 hours x 30 days = 10.8 amp hours

The total capacity of your battery is probably only 12 or 13 amp hours.
I would give it a full charge and see how it goes.

Paul