Trouble keeping battery charged.

starter motor ? is the air temp cooler on ' hard to start days ' . maybe its too cool for a battery to crank a bugged starter.

I suggest you get a Digital Voltmeter - either permanently connected or just a multimeter.

Check the voltage after you've been driving around for half an hour at least - with the engine running a fast idle you should read at least 13.6 volts.

Next morning before turining ANY load including the Interior Light (switch it off) - It should read at least 12.8 volts.

Scoof,
It may be too obvious, but have you had the battery checked?
One would assume an auto sparky would have done this first, but these days you just never know.

Failing that, is the alternator charging?
Start the car, then disconnect the positive terminal.
If she conks out, its using battery power and getting nothing from the alternator.

Don't know how helpful I've been, but hope it helps.

Brian

You need to do a current draw test, make sure everything is switched off, keys out of ignition and doors closed. Disconnect the cars battery negative and connect a good quality multimeter which has been been switched to read amps between the negative terminal of the battery and the disconnected clamp. The reading will at first be quite high but will gradually drop after a few minutes as the various control modules shut down, to read around 0.05 amps. If you are still getting a high reading after about 5 minutes, without breaking the multimeter connection, start removing fuses one at a time until the high current disappears. The fuse that drops the current is protecting the circuit that is causing the battery drain.
Hope you find this a help.
Jon

Hi Scoof,
Had a similar situation with my 100 series recently. For quite a while the battery would lose itself after standing for a few days. Seemed OK while away on a trip, but the caravan and auxilliary didn't really appear to get properly charged. Voltage output seemed alright, so couldn't really pin it down.

Eventually, a couple of months later, the alternator spat the dummy and whilst still putting out some charge, it became obvious there was a problem with it. Replaced with an after market job (Toyota MUCH too expensive!) and all batteries are now charged as they should be.

The point I'm making here is, that my alternator slowly failed and because of this, it was difficult to diagnose until it got to point where it almost failed completely.

Really, as suggested above, unless you have a constant discharge or leak somewhere, it can only be the battery or the alternator.

Good luck - hope you sort it soon.

Cheers
Gerry

Scoof,

Place a voltmeter across the starting battery and measure the voltage with the engine running. A fast idle should show around 14.1 volts. This will indicate if the alternator is putting a charge into the primary battery.

Do the same with the auxiliary battery. If the the primary battery is holding a good charge, the dual battery controller should allow a charging current to flow into the auxiliary battery and that should also show around 14.1 volts.

I am not familiar with the Redarc isolator but if it doesn't keep the two batteries electrically separated from each other, I would chuck it and replace it with another type.

If one of your batteries is faulty and the two batteries are connected together via the controller, the otherwise good battery will be "pulled down" to the level of the flattest one.

I assume the auto electrician would know his stuff, but I would charge bother batteries with your 240 volt charger then take them to a battery reseller and ask if they can be load tested. This will place a heavy load on them and indicate if one or both are faulty.

Apart from the above, the only other possible cause could be a poor earth. Ensure both batteries have a sound earth via heavy duty battery cables to the engine block.

Bill

Scoof,

If you have a trailer plug on the back get this checked out. It's a little known, but common problem.

A minor short in the plug will slowly, but surely, flatten your battery.

Cheers,

Jim.

I had the same problem with the Rangie. The problem turned out to be a new wireless energy moniter fitted to moniter our electricity usage at home.

What was happening is that it was broadcasting all the time on a similar frequency to the Rangie remote, the Rangie radio receiver for the remote says, I see a radio signal, lets turn the computer on and wait for the correct code from the remote.

The code never came, the computer in the Rangie was on all the time and flattening the battery.

It took 3 days of searching on the net for answers, talking to mates and pulling fuses, etc before finding the problem.

I put a ammeter in series with the battery and found it was drawing 2.4amps with the computer on and 0.02amps with it in sleep mode. I took the vehicle into the bush and did the test there with no radio anywhere close and all was OK, then went home and switched off anything radio until I found the energy moniter.

The other problem I found was that the computer would take 5 mins to go to sleep so turning off a radio transmitter, I had to wait 5 mins before I saw the effect, then turning it back on, the computer woke up instantly.

It is amazing how many radio transmitter devices I have around home incl WiFi, 2 x cordless phone systems (1 VOIP), Wireless energy moiniter, etc.

Good luck with your one and my guess it has a different problem but you never know if the dealer finds that all is OK becuase he may not have the same type of radio stuff that you may have at home.

Stevesub