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Disconnect battery terminal


Alexus2727
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Neutral Newbie

Intend to leave country for about 10 days..was told to disconnect battery terminal to prevent battery from being flat by the time i returned...

Will the engine computer settings be affected?

Are there anything I must do,besides connect the terminal back to the battery?

Pls advise....thks

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Neutral Newbie

Hi

 

 

Welcome to MCF. Hope you enjoy your stay with us and hope to see you at our meet up soon.

 

 

So what

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>>Intend to leave country for about 10 days..was told to disconnect battery terminal to prevent battery from being flat by the time i returned...

 

Who told you this?

 

I have left my cars undriven / unstarted for 14 days at a time, with alarm armed.

 

No problem on return.

 

How old is your car? How old is your battery? What car do you have ? Some cars may have a ECU / instrumentation problem if the battery is disconnected for a significant length of time.

 

For Nissan I know that the ECU settings are lost when the battery is disconnected. This is not a bad thing because if you have been driving slowly and the ECU "learns" your habits, you may want it to "forget" how you have been driving in case you want to go for a fast and hard drive, in which case you will disconnect the battery for at least 30 minutes to allow the ECU to "forget" your driving style and relearn a hard driving style (transmission shift points, mixture settings etc).

 

>>Are there anything I must do,besides connect the terminal back to the battery?

 

When you reconnect the battery you have to set your clock and radio memory again. If you think this is too much hassle you can buy a small device that plugs into your cigarette lighter that is powered by a 9-volt battery. It is claimed to supply enough power to your car clock and radio memories to keep them "alive". About $40 from AllTools Trading on Lavender Street.

 

BTW, always connect the positive (RED) terminal first. Then the negative (BLACK / ground) cable.

 

When disconnecting, undo the negative terminal first.

 

This is to avoid sparking which can startle you into banging your head or something worse (since you need to ask you probably haven't done it before).

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Neutral Newbie

thanks for replying.So,basically I just reconnect the battery terminal and then thats it?Can strait away drive the car?No adjustments or anything?

Me driving Toyota Harrier RX300..

Now I feel relived..

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>>thanks for replying.So,basically I just reconnect the battery terminal and then thats it?Can strait away drive the car?No adjustments or anything?

 

Wait wait wait. I didn't say RX300 can simply anyhow disconnect. I said Nissan no problem. I don't know about RX300.

 

Aiya, what for you want to disconnect?

 

How old can your RX300 be (and therefore how old can your battery be)?

 

The most is battery flat lor, so what? We don't live in a cold place where flat battery = no start = maybe freeze to death by the roadside. We also don't live in a high crime area where flat battery = no start = kena robbed and beaten. The worst thing that can happen here in Singapore is late for appointment, just take taxi lor, so what?

 

If that happens just call AA or use your trusty jumper cable (you DO have a jumper cable, don't you?) and "borrow" some power from a neighbour or friend lor!

 

The bad consequences of cocking up the connecting / disconnecting vs the bad consequences of a flat battery, which one is worse?

 

I have heard of cases where anyhow connect back in the wrong sequence, then power surge, then electronics all blur - eg airbag light keep flashing (happened to my friend's Odyssey - he disconnected battery to fix hifi, then connect back, problem come).

 

So now no trouble, what for go and make chance for trouble to come?

 

>>Me driving Toyota Harrier RX300..

 

Therefore cannot be very old, right, so battery likely to be healthy enough to tahan 10 days no start.

 

>>Now I feel relived..

 

Aiya, you worry so much for what?

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I think that is for old cars, I have left my car with the battery plugged in for 4 weeks and it started without a problem, even with the alarm on. Don't worry about it. If it doubt, call your SE and ask.

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there's no need to do that, I left my 8 yrs old Alfa 33 16v for 4 & 1/2 weeks & didn't even disconnect the battery, my friend only remember to start the car once during the first Sunday. I go back & the car started on the first crank (it's a 2yr+ battery) nod.gifthumbsup.gifthumbsup.gifthumbsup.gif

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Neutral Newbie

hi there, i think it is better not to unplug you battery or you may may to sent you car back to borneo motor for ECU reset. as all the setting may go mad it the battery is unplug for some time......

 

 

karen

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don't think it will cause any harm if the battery are disconnected. The most is the ECU will be reset & all your radio settings will be gone, that's all. Unless you have a Piggy back ECU that's dyno tune as all the settings will be gone & need to be dyno tune again if I'm not wrong sweatdrop.gifsweatdrop.gifsweatdrop.gifsweatdrop.gif

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Neutral Newbie

Piggy back is static, won't reset. Even if reset, can always upload or re-key in.

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Neutral Newbie

One exception.. for Mit Lancer, I know that for certain model (2000 and below), if the ECU ground cable is disconnected.. your car will or may not start again if discharge for 2 long.

 

take it as a pinch of salt from me or ignore me if you wish.

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Neutral Newbie

One exception.. for Mit Lancer, I know that for certain model (2000 and below), if the ECU ground cable is disconnected.. your car will or may not start again if discharge for 2 long.

 

hehe.... no i will never unplug my car, at the most i will call AA and replace the

battery,

 

 

take it as a pinch of salt from me or ignore me if you wish

 

its ok....... i agree on what you said.

 

thank you and regards

 

cheers

karen

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