Dodgy Battery? Rav 4.1 - 1995

[Worlds End Stu]

Hi All,

In November I had an issue with the Battery. The previous owner had fitted the wrong type with smaller terminals and had bodged it to fit and I had a loose connection problem.

New Battery fitted, problem sorted.

However... In recent weeks i've noticed a reluctance for the RAV to turn over and interior lights are quite dim before the engine is started and on a couple of occassions there wasn't enough power to open the remote locks so to me it sounds like the Battery could be a bit dodgy.

As the RAV gets irregular use (sometimes only 2 or 3 short trips and 1 medium sized trip per week) I put the battery on a maintenance charger but it doesn't seem to have made much difference.

I put the battery on a load tester and it just passed. Right at the bottom of the zone a couple of needle widths from "bad".

So my questions are...

1. Despite the battery only being a few months old could it really be borderline bad?

2. Is there anything I should check on the RAV that could've failed and as a result is now draining the battery quicker than previously?

Any ideas?

Cheers!

Stu

[anchorman]

The Battery should have a minimum 12 hour trickle charge then drop tested again. You could then just check around and see is evrything is going off like the boot light etc. Alarms can cause problems. If fitted try leaving it off to validate the test.

[Tech01]

Hi Stu from Worlds End (I know where that is!) . . .

Do what Don suggests. Also, if you have a multimeter, do the following:

1 Connect up one Battery terminal as normal.

2 With second terminal disconnected, set the meter to Amps and connect it between this terminal and the disconnected Battery lead. The meter will now read any current flowing out of the Battery.

3 Make sure EVERYTHING on the vehicle is switched off (lights, ignition, interior lights, radio...) and check the meter reading. It should be almost zero.

4 Switch meter to Milliamps (1000x more sensitive). The current flowing out of the battery should be around 50mA maximum, possibly as low as 10-20mA. Anything more than 50mA, and something somewhere is gradually flattening your battery.

Usual suspects are interior light (not going out), alternator (faulty component - check the current drain in same method as above, but pull the vehicle fuse marked ALT, which fuses the "permanent live" to the alternator, and isn't cut off by the ignition switch), radio/alarm (pull fuse to check). In fact, if you have an unhelpful current drain, then pulling fuses one at a time helps to pin it down.

Some neighbours of mine (petrol RAV same as yours) had the same fault last year. An idiot automotive "electrician" had replaced the 3-pin connector to the alternator, and managed to reverse two of the cables! Same result: battery flat after 2-3 days. Obviously, this couldn't happen twice!?

Good luck,

Chris

[Worlds End Stu]

I can't believe it's nearly 2 years since I started this thread and i've lived with the problem that long (yikes!).

As you may have guessed the RAV doesn't get used much but I decided it was time to sort this out once and for all.....

Gave the Battery a good charge and then as Chris suggested I hooked up the multi meter and I discovered that with everything off the car was drawing 10 - 20 milliamps. Happy days.

However, when I opened any of the doors (even though the interior lights were all switched off) the draw went up tp 160 - 200 milliamps and I discovered that sometimes when I shut a door the current was continued to be drawn until I gave it a good slam.

Does this sound like it might be the culprit, would a continous 160 - 200 ma draw over a couple of days flatten the Battery?

[gjnorthall]

200mA will flatten a Battery in a few days - I would have thought a couple of days would be lowside but depends on a number of factors. An interior light would consume around 400mA.

If the current draw is associated with opening and closing doors then the two possible culprits are the interior light and the central locking. I know that the internal light was switched off but the door switches also feed the central locking ECU - the door open signal stops the doors locking if a door is open. The other possibility is a fault in the central locking system. As first test, I'd disconnect the central locking ECU and repeat your test to measure current leakage.