-
The Z Club relies on the support of it's paid members - join the club or renew your membership here.
Battery Drained!
- Thread starter vrs9
- Start date
Has the car been run (or battery charged) during the month?
My 240Z would be 'iffy' after a month.
Clock will drain it slowly - no interior light left on, glove box etc?
Saw a 'Ring' smart charger in Tesco the other day for £7! Low current (really for small cars and motorbikes) but would keep the battery 'topped-up' .
My 240Z would be 'iffy' after a month.
Clock will drain it slowly - no interior light left on, glove box etc?
Saw a 'Ring' smart charger in Tesco the other day for £7! Low current (really for small cars and motorbikes) but would keep the battery 'topped-up' .
Rob,
Can has been out at weekends nothing major two or three hours of running. Installed a new clock when i bought the car its ticking away!!! Maybe previous owner had it dismantled for a reason! No interior lights left on anyways. Going to stick it on a charger for a while see what happens. Would it be worth while installing a switch for the battery i wonder?? Was worried it might be the starter or alternator.
Paul
Can has been out at weekends nothing major two or three hours of running. Installed a new clock when i bought the car its ticking away!!! Maybe previous owner had it dismantled for a reason! No interior lights left on anyways. Going to stick it on a charger for a while see what happens. Would it be worth while installing a switch for the battery i wonder?? Was worried it might be the starter or alternator.
Paul
rallymanDP
Well-Known Forum User
Two things -
a) if the Battery was new a month or so ago, then you have a drain somewhere in the system - have it checked out with a meter, but as said above, a good chance it is the Alternator Diode failed;
b) If you don't use the car for a few weeks at a time, invest about £30 in on of the Battery Saver devices - they keep it topped up & cannot overcharge.
a) if the Battery was new a month or so ago, then you have a drain somewhere in the system - have it checked out with a meter, but as said above, a good chance it is the Alternator Diode failed;
b) If you don't use the car for a few weeks at a time, invest about £30 in on of the Battery Saver devices - they keep it topped up & cannot overcharge.
Throttleton
Well-Known Forum User
Advice above sounds right.
Where did you check the voltage reading??
Charge up the battery and when you try to start the car take a voltage reading at the starter and make sure its nearly 12 volts.
Also which you will have probs done allready is when the car is running take a voltage test on the battery and make sure its a bit more than 12 volts nearer 13 to make sure the alternator is working.
Where did you check the voltage reading??
Charge up the battery and when you try to start the car take a voltage reading at the starter and make sure its nearly 12 volts.
Also which you will have probs done allready is when the car is running take a voltage test on the battery and make sure its a bit more than 12 volts nearer 13 to make sure the alternator is working.
rallymanDP
Well-Known Forum User
I hate to tell you, Paul, but I think you might be curing the symptom and not the problem.
Just reading the output of the Alternator on the Guage will not indicate if there is a drain on the system somewhere.
A two minute test at your local Lucas Auto-Electrical place will find out the real problem ( for free ), as a newish Battery should hold its charge for several weeks without going flat.
Just reading the output of the Alternator on the Guage will not indicate if there is a drain on the system somewhere.
A two minute test at your local Lucas Auto-Electrical place will find out the real problem ( for free ), as a newish Battery should hold its charge for several weeks without going flat.
I am in agreement there, technically you could start the engine then disconnect the battery and still have a running engine with 12-14 volt reading on the dashboard, as once the alternator has received an excitation current to the rotor (from the battery), it will deliver an output, power the coil, run the engine etc and deflect the gauge
so any info cleaned from the dashboard is inherantly flawed.
Get the battery "drop tested", (no that doesnt mean.
) then if thats ok, reconnect it and with all switches off (ignition key out) drop a test meter (set to amps) in series with +ve and look at the current drain, this should be almost nothing, maybe a milliamp for the clock, if it shows anything more then start taking fuses out until it is zero.
Warning dont drop a test meter set to read amps "across" a battery as it will deliver and show short circuit current which is many many hundreds of amps and will fry a test meter before the fuse can blow.
Don't belive me !!!! well in a DC circuit, Current = Voltage/Resitance or I = V/R so I = 12/0.01 (typical short circuit value) = 1200 amps
Warning when using a test meter in series to measure current, make sure it is set to "amps" not Ohms otherwise you will be buying a new meter (see above)
As Duncan rightly says deal with the cause not the symptom
so any info cleaned from the dashboard is inherantly flawed.
Get the battery "drop tested", (no that doesnt mean.
) then if thats ok, reconnect it and with all switches off (ignition key out) drop a test meter (set to amps) in series with +ve and look at the current drain, this should be almost nothing, maybe a milliamp for the clock, if it shows anything more then start taking fuses out until it is zero.Warning dont drop a test meter set to read amps "across" a battery as it will deliver and show short circuit current which is many many hundreds of amps and will fry a test meter before the fuse can blow.
Don't belive me !!!! well in a DC circuit, Current = Voltage/Resitance or I = V/R so I = 12/0.01 (typical short circuit value) = 1200 amps
Warning when using a test meter in series to measure current, make sure it is set to "amps" not Ohms otherwise you will be buying a new meter (see above)
As Duncan rightly says deal with the cause not the symptom
Last edited by a moderator:
mattbibbey
Well-Known Forum User
To be honest I haven't read through all the replies here but I did have a similar problem although it'd take a fortnight to drain. In the end, it looked like fixing the problem would cost so I just disconnect a battery terminal. Simple but it works, it's not ideal coz you'll still know there's a problem....