Optima Yellow Top Issues

[seqfisho]

This is probably the wrong place but as it is in the battery compartment under Hanks passenger seat it definitely is Defender related:p

We were giving Hank the big clean out yesterday, 12 years of red dust and grime, while cleaning away I discovered the stereo wouldn't turn on, possibly caused by the fact that the center dash has been slowly self destructing most likely caused by 250K km's of corrugations and off-road travels.

So as I dived into the dash to fault find, expecting that the movement of the stereo unit had somehow dislodged a wire or plug. Unfortunately what I found was something akin to the Prince of Darkness's failed attempt at becoming a spaghetti maker, wow what a nightmare:o

Anyway after checking the power plug for the stereo it was discovered that it was only reading 6.3V, mmm me thinks a bad connection somewhere in this tangled mess, however after disassembling most of the dash and discovering the feed runs back to the auxillary battery I check it's voltage directly at the terminals and suprise suprise only 6.3v there too, which means I could have saved myself around 2 hours tracing wires and rebuilding the dash:mad:

As I have never had anything to do with AGM batteries before, do they drop cells like normal wet cell batteries.

Do they discharge that low if left for a couple of weeks before recharging.

Hank has a Traxide SC80 DBS, and the led is solid yellow which I believe means the main battery is ok and they are isolated from each other.

I didnt check to see if the voltage went up with the motor running as I was out of time and the mossies were congregating:eek:

We will be taking Hank for a run today and I'll check the battery when I get back, but I'm suspecting it will be stuffed:(

[DiscoMick]

How old is the battery? You could put it on a multi-stage charger for maybe a week to recodition it and see if it will hold the charge. Batteries, including AGMs, need regular charging to stay healthy.

Sent from my SM-G900I using AULRO mobile app

[drivesafe]

Hi Glen, the LED on the SC80 should only be solid after the motor has started and with such a low auxiliary battery, the LED could start flashing again not long after turning the motor off.

If the LED was solid before you started your motor, there is a problem and most likely at the SC80.

If you get a chance, measure te voltage of both batteries before you start your motor and again after after you start your motor.

[seqfisho]

Had a quick check when we got home, did a little over 250km all up with about 200 of that at 90-95kmh the rest was crawling and bush tracks although still with a few revs on.

Unfortunately I forgot to check with the motor running, but at rest the Aux still 6.3v and the main was 12.8v, the SC80 led was solid.

If I get home early enough one afternoon this week I'll kick Hank in the guts and measure again.

[slug_burner]

I have had my yellow top D31 I think, it has the offset round wound plates very flat and it comes back ok after a day or two on a multi stage charger.

Good luck, don't give up until you have tried to recover it.

[DiscoMick]

Needs more than a drive to recharge if that low. Give it several days on a multi-stage charger and then see. Doesn't sound good.
As Drivesafe said, also see if the light is solid yellow both before starting and with motor running.

Sent from my SM-G900I using AULRO mobile app

[drivesafe]

Unfortunately I forgot to check with the motor running, but at rest the Aux still 6.3v and the main was 12.8v, the SC80 led was solid.

Hi Glen and there is a problem.

Can either sort it out on here, works as a good instructional session for others, or you can phone me and I will walk you through a few basic tests, but it does look like the problem may be the SC80.

[Fluids]

I'm with Tim on this one ... If the LED was solid, the SC80 has both batteries connected, and therefore, you should get as good as the same voltage reading at both batteries .... Except the SC80 isn't actually connecting the batteries, even though it says it is .... Meaning the aux optima hasn't been getting any charge for quite a while.

I could be wrong .... ???

[drivesafe]

Hi Kev and yes that is my ASSUMPTION at this stage.

Most likely the SC80, but it could be a number of other causes.

The most common problem I deal with is bad earth connections.

I had a situation just recently where the voltage across the auxiliary battery's terminals was 7.0v but the SC80 had 13.9v on both the input and output, with the motor running.

The auxiliary battery negative terminal to earth was measuring 6+v. It should have been 0v.

The earth connection to the body had not been tightened up properly and had worked itself loose.

[DiscoMick]

So (sorry if this is a dumb Q but I'm just a mug punter about electrickery), should his first step be to make sure all his earths are good?
If the earths are OK, then what?
If the second battery is cactus, but the first battery is good, so the SC80 keeps them connected, then would the first battery be sucking down the dud second battery?

[seqfisho]

I'll be checking through this in the next day or two.

Tim I'm more than happy to walk through the steps on here as it may be useful to others down the track.

[drivesafe]

OK then lets start by ruling the SC80 in or out, as the cause.

If the GREEN LED is on constant, measure the voltage at your cranking battery's positive terminal.

Then measure the voltage at the two studs on the Circuit Breaker, mounted on the side of the SC80.

the voltage should be the same at all three points.

[seqfisho]

OK then lets start by ruling the SC80 in or out, as the cause.

If the GREEN LED is on constant, measure the voltage at your cranking battery's positive terminal.

Then measure the voltage at the two studs on the Circuit Breaker, mounted on the side of the SC80.

the voltage should be the same at all three points.

Sorry for the delay but have had some diffuculty getting access to measure as we have just had about 300mm of rain over the last couple of days with 140mm in the last 24hrs:o

I ducked out quick this morning between downpours and measured the following

Motor off, and has been standing since last Sunday.

Main Batt + stud to earth on car 12.1v, and across both terminals the same 12.1v

Aux Batt + stud to earth now 6.25v and same across both terminals.

SC80 "Yellow" LED is solid.

Now motor on, and it fired first crank with no hesitation.:cool:

Main Batt + stud to earth and across both terminals 14.4v

Aux Batt + stud to earth and across both terminals 6.25v

SC80 LED status, solid Yellow, I had it running for about 5 mins before the heavens started to open and I high tailed it back inside.:mad:


Oh and guess what, no leaks inside my Defender:D







May have something to do with the giant silver tarp I've got over it............hahahahahahahahahahahahaha:p

[drivesafe]

Hi Glen, are you saying that you had high voltage readings on both the studs on the circuit breaker but a low voltage on the auxiliary battery positive ( + ) terminal to earth was reading just 6.25v?

If this was the case, try placing your multi meter's positive probe on one of the circuit breaker's studs and the negative probe on the auxiliary battery's positive ( + ) terminal.

My guess is that you are going to get another 6.?v reading.

[seqfisho]

Hi Tim,

No I only read the voltages at the battery terminals, I didn't read your instructions before I grabbed my window of opportunity:mad:

I will try and get a measurement at the C/B studs if I get another break in the weather
BTW, this is the SC80 that doesn't have a C/B built in, just the twin tails coming out of the unit, like an SC40 x 2.

I have no idea how old it is as it was already on the car and may have been there for some time, having said that though my SC40 is about 12 yo now and on it's second car and still going strong:D

[drivesafe]

When you get a chance, just measure the RED going into the SC80 and the GREY coming out.

If the LED is constant, and the voltages are different, it's the SC80 is the problem and if so, no matter how old it is, it is still under warranty.

If the voltages are the same, the problem is in the cabling between the two batteries, but it does sound like the SC80 is the problem.

[seqfisho]

Just got another "window" of opportunity, light shower actually so I had a good poke around with a torch through the jumbled spaghetti of wiring and found out that it is actually wired as follows:(

Red and grey are connected to the + terminal of the main battery and the blue and grey are connected to the + terminal of the aux battery, and the earth/exciter cable to a ground point on the body.


Unfortunately no protection in the form of a C/B or fuse in either :(

Although the cabling is very messy:mad::wasntme: it is sound with solid connections

https://www.aulro.com/afvb/images/imported/2016/03/802.jpg

[seqfisho]

I think I'll pull the optima out and see if my charger can save it if I try the recovery mode, as I would prefer not to have to replace the battery and DBS:(

[drivesafe]

Hi Glen, if you put the battery charger on your Optima and it does not turn on, get a set of jumper leads and connect your cranking battery to the Optima and then try turning on the charger.

Once the charger starts, disconnect the cranking battery.

Do not start your motor while trying to trick the charger into starting.

[seqfisho]

Hi Tim,


Am I right in thinking the SC80 should still try to put charge into the Optima when the motor is running or is there a significant delay if the Optimas voltage is too low or/if the SC80 can sense a fault on the Optima?

How long before the SC80 starts to put a charge into the Aux once the motor is running ?

[DiscoMick]

As I understand it (as a layman, could be wrong), that depends on the state of your charging battery. If it is charged beyond about 80% then normally most DBCs will then connect the second battery.
I would do what you propose and put the multi-stage charger on the Optima for several days and see how it goes.

[drivesafe]

How long before the SC80 starts to put a charge into the Aux once the motor is running ?

Hi Glen,it should turn on around 10 seconds after the motor started.

[seqfisho]

Well I finally got a chance to get the aux battery out this morning and throw it on the charger.

Whilst there I noticed the LED on the SC80 was flashing, checked the main batt voltage, 11.9v at least that bit works:D and the old girl still cranked over, first time for a week so happy about that.

Pulled the SC80 out, and had a look inside but I'll talk to Tim about that first.

Lets hope the optima can recover on the charger or it will be a new battery and controller:mad:

[seqfisho]

This mess will take a bit to sort out, looks like a Mulgo Ex Box coming right up and a few hours tracing circuits:mad:


https://www.aulro.com/afvb/images/imported/2016/03/584.jpg

Cant believe the yellow top was jammed in there aswell.