Have you suspected the Z clock? So the last flat battery thread was answered 3 years ago. I suspected my flat battery issue was the alternator or battery, checked both and after plugging a volt meter in the accessory (CIG) port, decided the alternator was probably doing an OK job. I left the car unlocked in the garage over night and found that she would start OK the next morning. Even a couple of days later, she started OK. I assumed the problem was the alarm, so tried locking car with key only. But I don't like leaving her without alarm or unlocked, so I replaced the battery and found that as long as I drove her every couple of days, she and the new battery would start OK. 12 months later, the problem is back so I bought one of those lithium jump start batteries. I have been using it every second day because the battery wouldn't seem to hold a deep charge. I must have noticed the clock was becoming intermittent. The clock misbehaved a bit with the old battery, but I dismissed that back then and mounted a voltmeter over the clock so hadn't noticed any possible warning that the clock might be the problem. So just putting this out there I unplugged my clock and my battery seems to be holding its charge.
How are you determining the battery is charged? How old is the battery? The battery will have a CCA rating, what is the current CCA figure of your battery? When you tested the alternator output, what was the ripple voltage figure? Have you tested the resistance of the wiring, terminals & connections? Have you considered the clock's erratic operation could be related to the supply voltage or connections rather than being the cause of the issue/s? Have you determined whether there is any parasitic drain from the battery?
Starting the car (or not) 12 months Big one, big enough, I'll go look. Instead of that, the volt meter in car shows anything from 12.7 to 14.5 volts when I sneak a peak while I am driving, sometimes with lights and Aircon. So it seems like it is doing its job. Yes Yes, then I unplugged it and car seems better. using the millivolt voltage drop method across at fuse box without removing fuses. It gives a clue where to check, like alarm or lights or turn signal relay. But then I disconnected the actual clock.
What you may be suffering from is parasitic battery drain, plenty of videos on YouTube and other Internet articles. It means when the car ignition is off there are small appliances or devices drawing a small amount of current from the battery. This is normal, alarms, stereos, clocks, TWD, remotes etc. It is possible for a clock to draw more power then it should as components deteriorate. The problem is when it gets too high it flattens the battery. How high is too high ? Well they say 50mA or more is too much, but you will find most of our cars will be well above this, with old alarms and accessories etc fitted, they can use more power then more modern alarms and with some incorrect fitting as well, like gauges etc on permanent power rather then a switched power. Batteries commonly had and ampere hour rating (Ah), they dont tend to do that on the Ca batteries now as I think they are a more a starting style battery and not designed to be flattened and charged IE cycled. But lets say a descent sized battery was 80Ah, there is quiet a bit more to this calculation and I am no digging out old books but for simplicity sake we will say that means a battery can supply 1A for 80 hours or 80A for 1 hour. So if you are drawing 300mA (milliamps as 300/1000 approx 1/3 of an Amp) as a parasitic drain your 80Ah battery will last 267 hours, awesome so it should last 11 days ! Well not quiet, most batteries are not fully charged as short runs etc accumulate as does the parasitic loss and brings the charge level down AND the voltage level to a point that the car wont start. So you jump start it drive it around and go THERE battery charged, not so its probably only 50% say. Then of coarse the problem happens quicker. The answer is to use a battery charger (like a Ctek MXS 5.0) to maintain the charge when you store the car or disconnect or correctly install the offending devices. Finding the offending devices is a s easy as using your multimeter on the current rang (A), disconnect a battery terminal put the meter in series and measure the drain, pull/disconnect fuses/devices and the reading will drop. If not sure google how to as you can damage your multimeter. The lower the better. Here is a laugh pull up in taxi turn the key off and get out and its drawing like 3A+, good thing that dont stop hey.
I also believe that modern batteries are lucky to last much more than a year before they start failing. It often seems that nearly every other car has a battery that does not hold a charge at work (panel beater). the reality is more likely 2-3 cars a week out of 20-30 jobs struggle to hold a charge over night. But that is still crap.
I think its fairly normal Stu, caryards, mechanics, panelbeaters are the reason jump packs were invented. What I described above has been going on for ages, as long as cars are driven on a regular basis (like a taxi with a 3A+ draw) there is little problem. But park them for a week or two as there would be out of 20-30 jobs and cars that were surviving on low levels of charge because they were daily driven are now quickly being flattened with in days of not being driven. It has no doubt probably gotten worse as more accessories and car systems have been added to cars over the years.
If my faulty clock isn't the main cause of the problem, it must be significant because my car sat for two and a half days and started without protest. The alarm is switched on too. Being able to jump in the car and drive off, would not have happened the other week when the clock was plugged in. As others have mentioned, any accessory can cause significant drain, I suspected my old alarm and next on the list was stereo, but I would not have suspected the Z clock until now.
flat battery Had this happen once in a commodore, it turned out to be the elec seat plug not in properly.
Mick, I just replaced all those 15 year old 994x relays under the dash and in the bay of the Commodore to cure an overnight flat battery problem. Luckily the relays in the Z32 are a bit better because they would be pushing 25 in most of our cars. Briz, I should undo my dash and check that clock and power plug, as you say, but at the moment I am getting in the car and it is starting every time. When the clock was plugged in, I had to use my LiO jump start battery every two days. So I am just grateful to be able to get in and drive right now and haven't touched the wires. Now I am noticing what feels like a flat spot on one or two of my tyres. So that is my focus right now. My suggestion is that if anyone has a clock that isn't really working, unplug it. I may have replaced a battery because of a faulty clock or connector and I also spent $189 on a LiO jump start battery.
Its worth mentioning that the 1990 model has power going to the injectors continually, not just when the car is on. I don't know why Nissan did this, but they must have realised it was a bad idea as its only on the very early models. This could be causing parasitic drain too.
Thanks, I have that model. Probably a mod out there to fix that. Wondering if that is the same mod to let me use fuel with ethanol in the mix, because if they start putting that stuff in all petrol grades, I'll need that anyway. Since the clock has been disconnected, I have started OK, 3 days between driving, but haven't gone more than 3 days without driving. That is a noticeable improvement for my car
