what's draining the battery? VDJ79 Landcruiser 2007 V8 4.5lt

Easy just put an multimeter set on amps in the line that sparks. Then start pulling fuses one at a tim untill the current draw disapears. Some newer vehicles ive checked have had upto 250Ma current drew for the many Computer keep alive memories.

Did the meter check, after I found the battery was going flat over time. turned out to be a dud diode in the alternator. The diodes can be replaced but easier to fit a new alternator.

Agree on the standing current though, ie clock, alarm system etc.

Peter

It might just be the battery is buggered, lots of things will "spark" when connected buy they may not draw continuous current.

If you have an electronic dual battery controller that will draw current but it will be bugger all.

If the battery wont start the vehicle when it is "fully charged" its probably "had the dong"

The age don't matter..if a battery has had it, it's had it.

Generally when batteries are near death all the properties of the battery go out the window, and one of those is self discharge.

You think you have damaged, what relay and how?

First point of action should be to put the battery on a good quality multistage charger and see how it goes......how long does it take to come up to "full charge" and how long does it hold charge , will it then crank.

cheers

Hi Mark,

It is not unusual to observe a small spark when reconnecting the battery. It is usually caused by electrolytic capacitors (condensers) being charged-up and does not necessarily mean that a significant current will continue to flow after the initial charge-up. Only by connecting a milliammeter in series with the wire will you determine if current is being continually drained from the battery. A small current will normally be continually drained by a few devices such as engine management systems and radios but this should not drain the battery.

What causes you to think that you have a "damaged a relay"?

Your cranking battery may be faulty with a high internal resistance. It can still indicate voltage of 12.4 or more yet not be able to supply the current needed by the starter motor. An indication would be to connect a voltmeter with the engine not running and observe the voltage drop when the headlights are switched on. If the voltage drops by more than about 1 volt then the battery is faulty.

Don't be to concerned.... most modern vehicles will flatten batteries if not started over a period of time.

You starter battery is only rated at 60 to 70 amps per hour so a load of 200 milliemps per hour will draw nearly 5 amps per day..... times that by 14 and your using 70 amps.

Most common power draws are factory radio and clock.

I have the same vehicle as you and over a week the cranking battery will go flat from fully charged.
I'll watch the thread.
Stan

Do you run a second battery and if so, what isolator?
What other aftermarket electrical gadgets have you got and what source of power?

This thread will probably go nowhere unless you measure the current and disconnect a few accessories to see what is drawing power.

PS 12.4 is not fully charged :-)

Have a look at the glove box light or something stupid like that. We just replaced our battery after 130,000.

Mark
12.4 volts, means that your battery is 50% state of charge or less, depending on what article you read, or who wrote it...Just Google "state of charge for lead acid battery" and have a good read.

Bang the battery on a charger for 2 nights in a row, checkk the voltage, and then drive it.
See what happens the next morning.

Check the voltage, if not 12.7v or 12.8 v, but 12.4v, then I would say the battery is history.
Also keep an eye on your auxillary battery, as it may go too !
Quite often one battery will carry the other, and it can be too much forthe Auxillary when a new battery is hooked up into the system

May no tbe 100% true, but that is what I have found

Cheers
Bucky

Two ideas for you, the first is I am wondering if you have a caravan brake controller fitted? I had a 100 series with a Tekonsha controller that intermittently flashed the brake
Lights when parked (apparently it was a fault with them), that drained the battery over about two weeks. The second is a faulty power relay to the engine management system, the EMS sucks power if it does not turn off, you could probably check that by measuring the quiescent battery current.

Hi Mark, Not sure if this will be helpful or not but I had a similar problem in my 60 series toyota and I couldn't leave it longer than 3 or 4 days without being able to start it. It turned out to be the electric brake controller which was using a heap of power in standby mode. I discovered that by unplugging it the battery is well upto starting the engine even after sitting for quite a while. I have plans to change the wiring so that the controller is linked to the ignition switch which will mean I won't have to remember to unplug it all the time!
Cheers,
Neil

My thoughts,
Original battery 20 months old is probably getting near the end of its useful life.
I have a similar vehicle, bought new in July 2007, battery started going flat if the vehicle was not started for a week or more, after about 2 years. Recharged the battery several times to no avail. Replaced the battery with a new one and problem solved.
My suggestion, fit a good quality new battery.
Cheers,
Derek.

Many thanks for all your replies. I fitted another battery - and it started no problem! That might solve the other problem of what is discharging the battery (over 10-14 days) as well! Hope so anyway, but if not I'll pull the fuses out one by one. No light in the glove-box, nor any trailer braking device.
thanks again, much appreciated.
regards, Mark