Flat battery - thoughts?

[Kersidan]

Long story short (ish). The C4S been stored over winter at the MIL's (large warm dry garage). MIL is in a local home due to dementia so we go up to the house every few weeks to check on things.

Arrived yesterday to find that someone had unplugged the CTEK charger, battery total flat. Not a huge problem as the car was unlocked and alarm not set. However when reconnected the CTEK it would not charge the battery... power LED on charger flashing which indicates no battery connected. Checked connections, all OK but still doesn't see the battery.

I'm assuming that battery is goosed and will buy another. I just wanted to check to see if there's anything I need to be aware of when reconnecting the new battery to avoid causing issues with ECU units or other issues?

TIA

 

[Magic919]

If you can show the CTEK some voltage it'll have a go at recovering it. It won't send a charge otherwise.

 

[deMort]

Replacing and fitting a new battery .. undo the negative lead first then the positive .. refitting and its positive first then neg .

To lift it out .. stand in the tub .. towel on the bulkhead panel .. lift the battery onto this then out of the car .. saves your back !!!

After fitting .. windows up then hold in the closed position for 5 seconds both sides .. reset the clock .. turn the ignition on but don't touch the throttle for about 30 seconds then turn off and remove the ignition keys .

Drive the car .. you will get a steering message but once driven over 6 mph that will go and not come back .

 

[Kersidan]

Replacing and fitting a new battery .. undo the negative lead first then the positive .. refitting and its positive first then neg .

To lift it out .. stand in the tub .. towel on the bulkhead panel .. lift the battery onto this then out of the car .. saves your back !!!

After fitting .. windows up then hold in the closed position for 5 seconds both sides .. reset the clock .. turn the ignition on but don't touch the throttle for about 30 seconds then turn off and remove the ignition keys .

Drive the car .. you will get a steering message but once driven over 6 mph that will go and not come back .

Thank you, just the info I needed.

You're a star.

 

[Kersidan]

If you can show the CTEK some voltage it'll have a go at recovering it. It won't send a charge otherwise.

That's a thought I'll try and get a standard charger and get some voltage into the battery and see if the CTEK goes from there.

Thanks

 

[MisterCorn]

If the battery incompletely flat it is most likely toast even if you do manage to recover it. I'd just get a new one.
Key in the ignition on position 1 when you connect it to stop the alarm going off.

MC

 

[Kersidan]

I got some volts into the battery from a standard charger, the CTEK then took over. I've left it on the CTEK for the time being but as advised I'll get a new battery to avoid problems.

Thanks!

 

[peterg1955]

and put a sign on the CTEK plug saying "please do not disconnect"

 

[Kersidan]

and put a sign on the CTEK plug saying "please do not disconnect"

Ha! Did that yesterday upon leaving the MiLs house!

 

[Alex]

I'd be checking how much current is being drawn off. Sounds like you havea short.

 

[asterix_the_gaul]

Being an expert of long experience of recovering dead batteries and killing them, it depends on your charger, some smart chargers are smarter or dumber than others, the ctek needs to see a voltage, you can do this by connecting jump leads from another battery, don't have to jump start it from another car or anything or even have the battery in another car, just so the charger sees a voltage and starts charging, you can then unhook the other battery and leave the ctek to get to work. You can of course dump a new battery in but it's worth trying to revive the one you have. If you do get a new battery keep the receipt in the files so you can get a replacement on warranty if you kill it again.

 

[Kersidan]

I'd be checking how much current is being drawn off. Sounds like you havea short.

Yep, worthwhile doing I agree. It was off the CTEK for about 6 weeks with possibly an interior light on as well but I'm not certain. What current should I see being drawn under normal conditions i.e. ignition off, alarm not set?

TIA

 

[Kersidan]

Being an expert of long experience of recovering dead batteries and killing them, it depends on your charger, some smart chargers are smarter or dumber than others, the ctek needs to see a voltage, you can do this by connecting jump leads from another battery, don't have to jump start it from another car or anything or even have the battery in another car, just so the charger sees a voltage and starts charging, you can then unhook the other battery and leave the ctek to get to work. You can of course dump a new battery in but it's worth trying to revive the one you have. If you do get a new battery keep the receipt in the files so you can get a replacement on warranty if you kill it again.

That's hoe I got the CTEK to see the battery... I put it on a standard charger for 15 mins, enough to get some volts into it and the the CTEK was OK. I left it on a Recond charge cycle.

 

[Alex]

I'd be checking how much current is being drawn off. Sounds like you havea short.

Yep, worthwhile doing I agree. It was off the CTEK for about 6 weeks with possibly an interior light on as well but I'm not certain. What current should I see being drawn under normal conditions i.e. ignition off, alarm not set?

TIA

About 30ma with the alarm set but you need to leave it about an hour before you check it if you've had the ignition on due to the lambda heaters drawing current.. Mine was up at about 1700ma last week but after cleaning the plug on the tilt sensor and alarm siren I've got it down to 150ma. I'm happy with that......for now.


Demort gives a decent explanation of what to do in this thread:

http://911uk.com/viewtopic.php?t=140566

:thumbs:

 

[Kersidan]

I'd be checking how much current is being drawn off. Sounds like you havea short.

Yep, worthwhile doing I agree. It was off the CTEK for about 6 weeks with possibly an interior light on as well but I'm not certain. What current should I see being drawn under normal conditions i.e. ignition off, alarm not set?

TIA

About 30ma with the alarm set but you need to leave it about an hour before you check it if you've had the ignition on due to the lambda heaters drawing current.. Mine was up at about 1700ma last week but after cleaning the plug on the tilt sensor and alarm siren I've got it down to 150ma. I'm happy with that......for now.

Thanks Alex, I'll check it in a few weeks when back up at MiLs. I'll update then just for information.


Demort gives a decent explanation of what to do in this thread:

http://911uk.com/viewtopic.php?t=140566

:thumbs: