D3 Traxide DBS question

[juddo]

@drivesafe - or anyone else with advice.

I have a Traxide SC80-12 in my MY08 D3. Been installed for maybe 6 to 8 years. Battery is a Optima D34 and is a few years old.

Just got back from a camping trip where I have had some issues. The facts:
* Battery was not running the fridge for more than about 12 hours from fully charged. I checked the voltage and found that the fridge was cutting out at 11.7V.

* To change the cutout point on the Danfoss compressor you need to change a resistor across 2 terminals. Since I did not have any resistors, I decided to put a straight bridge (0 ohms). This is a cutout at 9.6V. I figured this is OK because Optima claim that their batteries are good for deep discharges. (will change it to around 10.5V later)

* A couple of days later I found that the Optima battery was no longer being charged by the alternator. Upon investigation I found that the SC80-12 circuit breaker (50A / 12V auto reset) was open circuit. After a while it cooled down and re-closed. I restarted the engine and the breaker tripped after about 1-2 seconds.

Please refer to the following photo:
134540

Please notice the following points:
* The circuit breaker has been bridged out with input and output connected to 1 terminal.
* The engine is running and the solenoid is closed (green light solid)
* Volt meter shows 13.36 Volts on D34. Starter battery was around 13.5.
* Tong tester shows 89.2 Amps flowing from starter battery to D34 battery. (easy to see why the CB keeps tripping).
* With engine off and connector between batteries disconnected, D34 showed 12.25V - this reading was taken a few minutes after the photo above.
* After reconnecting and restarting the engine, the current slowly dropped from the around 90A down to below 40A after another 10 minutes or so.
* Until this event, I have never knowingly had an issue with tripping the CB, so presumably the battery has never drawn this much current.

Questions:
1. Is this normal or to be expected with a heavily discharged Optima battery?
2. Do you believe that the event is due to a heavily discharged battery or some other issue?
3. Can you see any issue with letting the battery charge at this rate?
- Optima claim that there is no current limit for charging the yellow top batteries
- I took multiple readings of the temperature of the cable and connections (by touch only) and found that the temp never got any hotter than "warm to touch"
4. Any other comments?


Thanks for any assistance. Matt.

[Ean Austral]

I cant comment on to much , but what size fridge do you have ? My optima wont run our new fridge/freezer for any more than 10 hours, and that includes running the start battery down to 12v before the SC80 cuts out. Our old 40ltr Engel would run overnight but by 10am if there was now power to it then it would cut out.

I never had any issue's re-charging the optima, but it needed a good drive to get it fully recharged.

Prolly not much help but the optima is only 55ah. Don't think I have ever seen mine below 11V so cant help with any of your other questions. I am sure Tim will come along soon enough.

Cheers Ean

[drivesafe]

Hi Matt, 9.6v is way to low for the Optima and at that level, I would not be surprised if the initial inrush current went well over 100 amps.

With an Optima that low, when the SC80 turned on after you started your motor, the Optima would have draw all the current available from your alternator and pulled a fair bit of current from your cranking battery as well.

While not good for your Optima long term, you will be able to recharge it as you have been doing, but you really need to wire the 50 circuit breaker back in to the circuit.

It is there to protect.

Note, the CB can carry high currents for quite some time, before going open circuit. So for the circuit breaker to trip like that, your Optima must have been pulling well over 80+ amps.

[juddo]

I cant comment on to much , but what size fridge do you have ? My optima wont run our new fridge/freezer for any more than 10 hours, and that includes running the start battery down to 12v before the SC80 cuts out. Our old 40ltr Engel would run overnight but by 10am if there was now power to it then it would cut out.

I never had any issue's re-charging the optima, but it needed a good drive to get it fully recharged.

Prolly not much help but the optima is only 55ah. Don't think I have ever seen mine below 11V so cant help with any of your other questions. I am sure Tim will come along soon enough.

Cheers Ean

I have a bushman fridge in 45L configuration. Recently had the compressor replaced with a danfoss. It used to run on battery overnight until mid morning without charging. But since the replacement compressor the performance has been far less.

I put it down to 2 reasons. The compressor was set up to run at 3500 rpm. I have just reduced the speed to 2000rpm and it draws almost 1/2 the current while running and does not appear to run for much longer either. Other reason is the cutout was set to 11.7V. To me this is excessively high. I will purchase the correct resistor to set the cutout at a better level without damaging the battery.

Thanks for your input.

[Ean Austral]

I have a bushman fridge in 45L configuration. Recently had the compressor replaced with a danfoss. It used to run on battery overnight until mid morning without charging. But since the replacement compressor the performance has been far less.

I put it down to 2 reasons. The compressor was set up to run at 3500 rpm. I have just reduced the speed to 2000rpm and it draws almost 1/2 the current while running and does not appear to run for much longer either. Other reason is the cutout was set to 11.7V. To me this is excessively high. I will purchase the correct resistor to set the cutout at a better level without damaging the battery.

Thanks for your input.

I have gone the other direction, I should have my second auxillary battery fitted and connected today. My wife for some reason bought a - I think 90l or 95l dual compartment waeco fridge / freezer , so as you could imagine the yellow top doesn't last that long. I think I have that set at 11V or maybe 11.2V cutout.

Goodluck with the resetting of your fridge.

Cheers Ean

[juddo]

Hi Matt, 9.6v is way to low for the Optima and at that level, I would not be surprised if the initial inrush current went well over 100 amps.

With an Optima that low, when the SC80 turned on after you started your motor, the Optima would have draw all the current available from your alternator and pulled a fair bit of current from your cranking battery as well.

While not good for your Optima long term, you will be able to recharge it as you have been doing, but you really need to wire the 50 circuit breaker back in to the circuit.

It is there to protect.

Note, the CB can carry high currents for quite some time, before going open circuit. So for the circuit breaker to trip like that, your Optima must have been pulling well over 80+ amps.

Thanks for the advice Tim.

I will be putting the CB back into circuit. And resetting the fridge cutout. What would be your recommended voltage for the low-voltage cutout?

One other thing that I noticed; there was a large voltage drop from battery to the outlets in the back of car. Especially when fridge running. I found that the terminal block located behind the RH rear cover had come a little loose and the push on spade connectors for inline fuses were also loose. Tightening them all up made a big difference. It is probably something that should be checked regularly.

Cheers. Matt.

[juddo]

My wife for some reason bought a - I think 90l or 95l dual compartment waeco fridge / freezer , so as you could imagine the yellow top doesn't last that long.

Cheers Ean

Pretty huge fridge.

Where is the 3rd battery going? Charging both through the SC80?

[drivesafe]

Thanks for the advice Tim.

I will be putting the CB back into circuit. And resetting the fridge cutout. What would be your recommended voltage for the low-voltage cutout?

One other thing that I noticed; there was a large voltage drop from battery to the outlets in the back of car. Especially when fridge running. I found that the terminal block located behind the RH rear cover had come a little loose and the push on spade connectors for inline fuses were also loose. Tightening them all up made a big difference. It is probably something that should be checked regularly.

Cheers. Matt.
Hi again Matt, when using an Optima as the auxiliary battery, the ABG-25 can be set to 10.5v.

All new ABG-25s are now fitted with Yellow Crimp Terminals, to get around the very issue you have, and to both simplify and speed up an installation.

Try fitting crimp terminals to yours.

[Ean Austral]

Pretty huge fridge.

Where is the 3rd battery going? Charging both through the SC80?

Yes I know , I made a battery tray to fit in front of the start battery and the yellow top is fitted there, the other battery is going in the battery box where yours is in the picture on the first post. I spoke to Tim and he said the SC80 will run it fine. The other battery is bigger so if my measurements are correct and it fits , then when my yellow top dies I will replace it with the same brand /size as the extra I am fitting.

Cheers Ean

[Ean Austral]

https://www.aulro.com/afvb/images/imported/2018/01/348.jpghttps://www.aulro.com/afvb/images/imported/2018/01/349.jpg


That's the set up , will put the fridge/freezer in this weekend and see how well it goes. Second battery is an 85ah AGM , so if all goes well it should give me 140ah plus whatever the main battery puts in before the 12V cut out.

Cheers Ean

[loanrangie]

Ean, whats the brand and model number of the aux battery ?

[Ean Austral]

Ean, whats the brand and model number of the aux battery ?

https://www.aulro.com/afvb/images/imported/2018/01/350.jpg

That's the box it came in. I got it on sale just before chrissy under $200.

You need to do some slight trimming in the battery box to make it sit flat as its 8mm longer than the Optima , but not hard to do. You also need to make a new battery clamp as its higher than the Optima but some 6mm threaded rod and some flat bar covered in heat shrink and a couple holes drilled in it and bobs ya fathers brother.

With some reworking the earth leads on the other side there is enough room to mount 1 there as well which will be my plan when the Optima dies.
PS - you cant fit the cover back on , but I have removed mine anyway so doesn't bother me.

Cheers Ean

[Ean Austral]

So today I put the 95 ltr fridge/freezer into the car today , straight out the shed and not pre-cooled. Freezer set on -15 and fridge on 3 and after 6 hours the in-cab monitor I have tells me both the start battery & both Auxillary batteries are at 12.3V. Opened the bonnet and the SC-80 still shows the main battery is not isolated , which makes sense as it switches at 12V. Will see where we at come morning. https://www.aulro.com/afvb/images/imported/2018/01/471.jpg https://www.aulro.com/afvb/images/imported/2018/01/472.jpg

Admittingly I haven't been opening or closing the fridge , but the Optima struggled to run it overnight so time will tell how well it works.

Cheers Ean

[Ean Austral]

Just an update , 24 hours fridge is still running and the 2 Auxillary batteries are at 11.9V - Start is at 11.98. That will do me.[thumbsupbig]

Cheers Ean

[drivesafe]

Hi Ear, if you have not disconnected the load yet, can you keep your test running a little longer.


My isolators have an error margin of no more than 0.03v and the set point for cut-out voltage is 12.00v.


So the isolator should cut-out at or above 11.97v.


BTW, you can start your motor with a cranking battery voltage of 11.5v, so you have quite a lot to play with yet.

[Ean Austral]

Hi Ear, if you have not disconnected the load yet, can you keep your test running a little longer.


My isolators have an error margin of no more than 0.03v and the set point for cut-out voltage is 12.00v.


So the isolator should cut-out at or above 11.97v.


BTW, you can start your motor with a cranking battery voltage of 11.5v, so you have quite a lot to play with yet.

Gday Tim,

At 11.97V the isolator had already cut in and the Start battery was isolated. I put the 0.03V down to the fact the isolator is powered off the car battery and I had opened and closed the doors a few times.

I Started the car after 25.5 hours with the battery at 11.96V and it fired like normal. Remember I have 1 of the early SC-80-12 and even when I had just the Optima and the fridge had shut off due to its own low voltage cut off the main battery always had more than enough to start the car. This was a regular occurance on my last trip away hence the reason for more power

Its a great product and thanks for the honest advice that it was capable of adding the extra battery. I in no way want to steal your idea of having the 2nd auxillary battery, my goal was to find a bigger Ah battery then the Optima, but I also realise the trade off will be battery life of the cheaper battery.

Cheers Ean

[PeterJ]

https://www.aulro.com/afvb/images/imported/2018/01/348.jpghttps://www.aulro.com/afvb/images/imported/2018/01/349.jpg


That's the set up , will put the fridge/freezer in this weekend and see how well it goes. Second battery is an 85ah AGM , so if all goes well it should give me 140ah plus whatever the main battery puts in before the 12V cut out.

Cheers Ean

So here's an idea Ean, take that big lump of a diesel V6 out, a couple more batteries (you will have lots of space) and voila, electric D3[wink11]:lol2:

Impressive how you have made it all fit.

[orville]

Not sure about this thread, are you telling me I need 3 batteries just to run a fridge? I have a system that works without trickery and keeps everything cold. DC 27 + solar panel worked fine for last 7 months.

[loanrangie]

Not sure about this thread, are you telling me I need 3 batteries just to run a fridge? I have a system that works without trickery and keeps everything cold. DC 27 + solar panel worked fine for last 7 months.
He is running a fridge and freezer, 55ah from optima doesn't cut it.

[Ean Austral]

Not sure about this thread, are you telling me I need 3 batteries just to run a fridge? I have a system that works without trickery and keeps everything cold. DC 27 + solar panel worked fine for last 7 months.

Im not telling anybody they have to do anything. If you are happy with your system that's great.

If you read post #5 you will see why I went with the option of an extra battery. My original set up was fine with a 45ltr fridge but in our wet season when the sun isn't always able to charge solar panels and it was boardline, change it to a 95ltr fridge/freezer and be in area's where solar panels don't always get to see the sun and 55ah battery don't cut it.

Cheers Ean