Cranking and Aux Batteries dropping down to 50% charge: Traxide isolating

[BSM]

I've recently purchased a Genius G7200 charger (similar to CTEK), and begun to use it regularly.

I am finding that the battery charge is surprisingly low in my D3 , often at 50% after driving for a week. This is not stop-start city driving either, roughly 180km freeway driving per week.

I have a main cranking battery of indeterminate age, and a 4 month old Optima yellow top as the Auxiliary, fitted via Traxide D3-DS.

I was surprised today to see the green Led flashing on the Traxide SC-80 Isolator. This apparently means that the Isolator has kicked in, and thus separating the Main and Aux batteries.

There is no load on the Aux battery. There's nothing pugged into the sockets at all, so that must mean the current draw is from the regular D3 circuitry.

So here are my symptoms:
- Charger is indicating that both batteries (each individually)are getting down to 50% charge after about a week.
- SC80 isolator is tripping at some point during that week.

What might be going on here? Is it:

Alternator on the way out?
Main cranking battery on the way out
Unusual / very high vampire load on the regular D3 circuitry.
The charger's measurement of charge level is wrong?

[WhiteD3]

Sounds like you need a new crank battery. 2.x years is the best I've got out of a crank battery in my 8 years of D3, D4 ownership.

[drivesafe]

Hi BSM and from what you have posted, I'd say your cranking battery is on it's way out, but the Optima, via the SC80, is slowing the cranking battery's rate of discharge.

If it is on it's way out, the rate of discharge will increase and SC80 will cut out sooner.

You will find that your cranking battery will have a lower voltage than the Optima once the SC80 cuts out.

You can test to see if it is the cranking battery fairly easily.

Next time you have been for a long drive, disconnect the SC80.

Normally the easiest way to do this is to remove the thin earth wire on the SC80, but on the D3, this can be a bit of a task because of the location of the earth nut.

Best way to shut the dual battery system down is to first remove the negative ( - ) cable from the AUXILIARY battery.

Then removing the positive ( + ) cable from the cranking battery.

The instant you disconnect the positive cable from the cranking battery the SC80 will shut down.

I reckon your cranking battery will be flat in less than a day.

See how you go.

[LandyAndy]

First off check the battery charger.Is that an Aldi brand??? If so P38aRon had issuse with an Aldi CTek clone over charging,others did too if I recal.
You can check voltages with a multimeter.With full electric load there shold be better than 13.8V in the system with the motor running.If its less than 13V I would get the alternator checked.
Andrew

[BSM]

Hi BSM and from what you have posted, I'd say your cranking battery is on it's way out, but the Optima, via the SC80, is slowing the cranking battery's rate of discharge.

If it is on it's way out, the rate of discharge will increase and SC80 will cut out sooner.

You will find that your cranking battery will have a lower voltage than the Optima once the SC80 cuts out.

You can test to see if it is the cranking battery fairly easily.

Next time you have been for a long drive, disconnect the SC80.

Normally the easiest way to do this is to remove the thin earth wire on the SC80, but on the D3, this can be a bit of a task because of the location of the earth nut.

Best way to shut the dual battery system down is to first remove the negative ( - ) cable from the AUXILIARY battery.

Then removing the positive ( + ) cable from the cranking battery.

The instant you disconnect the positive cable from the cranking battery the SC80 will shut down.

I reckon your cranking battery will be flat in less than a day.

See how you go.

Hi Drivesafe, not quite sure how this test works. Do I disconnect both leads as you describe, and then reconnect them, then try again with the charger on the cranking battery the next day?

[BSM]

First off check the battery charger.Is that an Aldi brand??? If so P38aRon had issuse with an Aldi CTek clone over charging,others did too if I recal.
You can check voltages with a multimeter.With full electric load there shold be better than 13.8V in the system with the motor running.If its less than 13V I would get the alternator checked.
Andrew

It's not an Aldi brand. I think it's one of CTek's main competitor. A Ccmpany by the name of Noco Is the manufacturer. I selected it because It was a slightly better price and had a better range of connectors in the box.

[drivesafe]

Hi again BSM.

The test above is to see if your cranking battery is on it's way out.

With the batteries separated, you can charge each battery separately.

If neither battery charges, the as LandyAndy posted, the issue may be with the charger.

There is a third possibility for the problem and that is as you suggested, your alternator may be the cause, but start with the batteries and see what you get.

[BSM]

Thanks Drivesafe. One other thing. I noticed that even after I fully charge both batteries first individually, and then topping up just now via the Anderson plug, the led is still flashing on the isolator. I would have thought that when both batteries are fully charged the isolator would be reconnecting automatically, even if the cranking battery was quickly losing power once charging stops.

[drivesafe]

Hi BSM, and if the voltage on the cranking battery reached or exceeded 13.2v, the isolator should have turned on, but the state of both batteries has to stay above 12.0v

With out charging anything, try measuring the voltage of both batteries with the LED flashing on the SC80.

While the SC80 may not be operating properly, although there is no indication of this and the SC80 will not discharge batteries down to 12.0v in a week unless there is another problem.

You need to find the cause of the discharging before you can see why the SC80 is cutting out so quickly.

[BSM]

I have been doing a bit of under the bonnet electrical detective work using this excellent how-to from the UK Disco4 site. (http://www.disco4.com/forum/post1366423.html#1366423).

I purchased a cheapish Amp Clamp on-line to do this which as it turns out probably wasn't the best one I could have bought for this purpose because the jaws are hard to get into some places, and they won't open large enough to fit the huge starter motor cable, but nevertheless, I have got some useful readings.

I am seeing a quiescent current draw of about 88mA through the main cable from the battery to the junction box, which is four times recommended draw. Investigating the voltage drop across the fuses, I am seeing pretty much nothing on all of the fuses except for a reading across F26 of about 8OmA. This is the fuse to the suspension ECU.

Additionally I was reading 100mA through a straggly wire that comes out of the junction box, and dissapears into some flexible conduit and goes goodnes knows where.

I need to repeat my measurements, and hunt to down where this straggly wire goes because I ran out of daylight yesterday.

You can see the straggly wires I'm talking about hanging out from the battery box at the bottom of the attached image. Any idea what it might go to?

Incidently, can anyone tell me what the small black box is that is mounted in the engine bay directly aft of the washer bottle in that image? It has an integrated fuse, and the cables dissapear down the engine bay and I think go under the vehicle.

https://www.aulro.com/afvb/

[Redback]

I have been doing a bit of under the bonnet electrical detective work using this excellent how-to from the UK Disco4 site. (http://www.disco4.com/forum/post1366423.html#1366423).

I purchased a cheapish Amp Clamp on-line to do this which as it turns out probably wasn't the best one I could have bought for this purpose because the jaws are hard to get into some places, and they won't open large enough to fit the huge starter motor cable, but nevertheless, I have got some useful readings.

I am seeing a quiescent current draw of about 88mA through the main cable from the battery to the junction box, which is four times recommended draw. Investigating the voltage drop across the fuses, I am seeing pretty much nothing on all of the fuses except for a reading across F26 of about 8OmA. This is the fuse to the suspension ECU.

Additionally I was reading 100mA through a straggly wire that comes out of the junction box, and dissapears into some flexible conduit and goes goodnes knows where.

I need to repeat my measurements, and hunt to down where this straggly wire goes because I ran out of daylight yesterday.

You can see the straggly wires I'm talking about hanging out from the battery box at the bottom of the attached image. Any idea what it might go to?

Incidently, can anyone tell me what the small black box is that is mounted in the engine bay directly aft of the washer bottle in that image? It has an integrated fuse, and the cables dissapear down the engine bay and I think go under the vehicle.

http://www.aulro.com/afvb/attachment.php?attachmentid=91178&stc=1&d=1424899026


Driving lights, old dual battery system, if you bought the car second hand, they may have removed something when selling the car, could be something for towing, towing a trailer with LED lights, hands free kit, those scraggly wire are a fuse going back into where the main battery is, see where they go.

As for the black box, follow the wires from the black box, gotta lead to somewhere.

Baz.

[BSM]

Driving lights, old dual battery system, if you bought the car second hand, they may have removed something when selling the car, could be something for towing, towing a trailer with LED lights, hands free kit, those scraggly wire are a fuse going back into where the main battery is, see where they go.

As for the black box, follow the wires from the black box, gotta lead to somewhere.

Baz.

Yes is a second hand car. That black box is not an original piece of kit then I gather?

[bee utey]

The little black box looks like something you'd buy from Jaycar, probably a home made magic rust zapper, about as useful as mammaries on a male bovine. Pull the fuse, your car won't stop running.