Traxide Dual Battery Voltages

[rocket rod]

I know I could have asked this question of Tim directly but then none of you would get to know the answer, so I hope Tim is online and can explain things.

My questions is; I have his Traxide dual battery setup and a dual volt meter in the car so I can see what's going on. The batteries are always the same voltage 12.6V after car has been sitting overnight. When I open the drivers door the main battery voltage drops because of all the start up routines running. I get that, but what I don't get is that the aux battery also drops moments later as though it's going out in sympathy. My understanding was that the two batteries are kept separate by the Traxide system so if one drains the other doesn't? So why should the aux voltage drop when all I've just done is open the door?

[kelvo]

USI-160 - 160 amp Winch Isolator | TRAXIDE - RV | Traxide - RV (http://www.traxide.com.au/isolators/usi-160---160-amp-winch.html) Explains the voltages, you didn't say if you had the switchable USI-160 or the fixed SC80 kit.

The USI-160 will disconnect at 12.6V if in 'ignition' mode or 12.0V if in 'shared' mode.

The SC80 is fixed to disconnect at 12.0V.

[drivesafe]

Hi Rod and how much later is the auxiliary battery taking before it's voltage drops to the same level as the cranking battery?

BTW I to prefer people to post up questions like this on the forum, for the very same reason you posted. The answer may also be of assistance to others.

[Blknight.aus]

my guess

the traxide is keeping the batteries linked and depending on where your gauge is hooked up and what sort of gauge it is the voltage drop may not be instantaneous on the aux battery.

Additionally some digital volt gauges dont do continual measurements they only update every XX seconds

From memory if you have the newest unit it will allow back charging from the aux to the main so if the batteries are both disconnected, the main voltage dips, the aux is high enough that the permissable reconnect for charging the main battery threshold is exceeded it will reconnect the batteries.

This is part of the new system that lets you run solar straight to the aux battery and give it priority charging and then when its up at near fully charged the main battery gets a serve.

[winaje]

This is part of the new system that lets you run solar straight to the aux battery and give it priority charging and then when its up at near fully charged the main battery gets a serve.

Is this the case on all USI-160s?

[drivesafe]

Is this the case on all USI-160s?

Hi Will, REVERSE CHARGING is not yet available on the USI-160, only available on the DT90-L322 isolators and the new SC80

[rufusking]

Hi Will, REVERSE CHARGING is not yet available on the USI-160, only available on the DT90-L322 isolators and the new SC80

Tim, how do I know if I have a "NEW" SC80?

[drivesafe]

Hi refusing, if you placed an order in late March this year, all SC80-CB isolators shipped from the first of April are the new SC80 isolators.

Sorry for the delivery delays, and please note, there are still some delays with orders but as the new SC80 isolators are now in full production, I will be able to catch up and reduce the delivery times.

BUT, once I have delivery times back to under a week, I will be increasing most of my isolator and Dual Battery Kit prices.

[LRD414]

Tim I understood the older SC80 (mine is 2014) allowed for back-feed from aux to cranking that kept the cranking at a higher SoC all the time. So is the mentioned reverse charge something extra?

Cheers,
Scott

[wbowner]

Tim
I am sure I have misunderstood the reverse charging comment. I thought that was a feature if all sc80 units

I got my traxide set up in 2014. It was my understanding that the aux battery would supplement the main battery if the main is lower and visa versa.
With protections to not drain either.

Richard

[Briar]

Tim
I am sure I have misunderstood the reverse charging comment. I thought that was a feature if all sc80 units

I got my traxide set up in 2014. It was my understanding that the aux battery would supplement the main battery if the main is lower and visa versa.
With protections to not drain either.

Richard

Hi Richard
I'm in the same position as you. I ordered my Traxide system in Feb 2016 and installed it in March. I'm sure I discussed with Tim about how my caravan solar panels would charge up both car batteries through the SC80 when car and van are connected. I was certainly under that impression.

Trevor

[rocket rod]

Hi Rod and how much later is the auxiliary battery taking before it's voltage drops to the same level as the cranking battery?

BTW I to prefer people to post up questions like this on the forum, for the very same reason you posted. The answer may also be of assistance to others.

The main battery drops to about 12.4 when the door opens and a few seconds later so does the aux. Others here say the USI-160 (which I have) will go down to 12v before disconnecting in shared mode and I'm fine with that, I just wanted to make sure it is working properly. Thanks for all your replies.

[drivesafe]

Hi folks and yes, for the past 25 years, all my isolators have had the ability to allow REVERSE CHARGING and this has been the major difference between my isolators and all the others.

But the reverse charging was only available while the batteries were at or above 12.0v ( or 50% SoC ).

Once the isolator shutdown, the reverse charging was no longer available, unless you started and ran your motor for a minute or so

Over the past few years, more and more people were having problems, where something in the vehicle, discharged the batteries down to 12.0v.

This was usually caused by a fridge being used, but then once the isolator had shutdown, other factors would continue to discharge the cranking battery.

With D4s, this was usually people continually opening the doors and the tailgate, to access the fridge or to get things from the vehicle.

This sorts of use, on many occasions, lead to the cranking battery being discharged even further, and independently of the auxiliary battery.

Quite a few occasions have occurred where the cranking battery was flattened to the point you could not unlock the vehicle.

Now, with the new SC80, simply plug a battery charger or solar regulator to the Anderson plug at the rear of the D4, if fitted, and you can now first charge the auxiliary battery, then the SC80 will turn on and the cranking battery will be charged, allowing entry to the vehicle again.

You could even connect an Anderson plug jumper lead to another vehicle, and charge/jumpstart the D4 that way.

The isolator specifically charges the AUXILIARY battery first, and then turns on to charge the cranking battery.

The isolator has been programmed to work this way so that if the cranking battery is not just flat, but has dropped a cell, the auxiliary battery will still be ?NEAR? fully charged and should still allow you to start the motor.

This operation was devised after some discussions with Blknight, Thanks mate.

[LRD414]

The isolator specifically charges the AUXILIARY battery first, and then turns on to charge the cranking battery. The isolator has been programmed to work this way so that if the cranking battery is not just flat, but has dropped a cell, the auxiliary battery will still be ?NEAR? fully charged and should still allow you to start the motor
Thanks Tim, good to know & an excellent explanation.

So rather than replace my less-than-two-year-old SC80 that I'm very happy with, I have done the following to deal with the risk of a very low cranking battery:

- Lead with Ctek-12S to charge cranking battery through 12S (white) plug
- Lead with Ctek-Anderson to charge aux battery through Traxide rear Anderson plug
- Short cable on each positive terminal c/w 75A Anderson powerpole to allow aux battery to start vehicle if required by connecting the two leads together
Note: yet to actually build the last one but idea taken from <this Disco3 thread> (http://www.disco3.co.uk/forum/topic56911-15.html)

How does that all sound? Obviously the newer SC80 is more straightforward but do I have most scenarios covered?

Cheers,
Scott

Photos: Ctek-12S lead ----------------------------------------- and Anderson powerpole charge cable
https://www.aulro.com/afvb/images/imported/2016/06/721.jpghttps://www.aulro.com/afvb/images/imported/2016/06/722.jpg

[Mungus]

Hi Tim, Is this function something you will be introducing to the USI-160 in the near future?

[drivesafe]

Hi Mungus and yes, but not for some time.

I was originally intending to phase in the new SC80 on the 01/07/15 but because of the high numbers of orders I have been receiving for the past 18 months, it has taken this long to get the new SC80 up to full production.

I now will start on the upgraded version of the USI-160, but again, with the huge volume of work coming in, at this rate, it will not be till at least some time into the new year before an upgraded USI-160 is near ready.

[LRD414]

Tim, could you have a look at my post, just before Mungus.

Thanks,
Scott

[Blknight.aus]

Thanks Tim, good to know & an excellent explanation.

So rather than replace my less-than-two-year-old SC80 that I'm very happy with, I have done the following to deal with the risk of a very low cranking battery:

- Lead with Ctek-12S to charge cranking battery through 12S (white) plug
- Lead with Ctek-Anderson to charge aux battery through Traxide rear Anderson plug
- Short cable on each positive terminal c/w 75A Anderson powerpole to allow aux battery to start vehicle if required by connecting the two leads together
Note: yet to actually build the last one but idea taken from <this Disco3 thread> (http://www.disco3.co.uk/forum/topic56911-15.html)

How does that all sound? Obviously the newer SC80 is more straightforward but do I have most scenarios covered?

Cheers,
Scott

Photos: Ctek-12S lead ----------------------------------------- and Anderson powerpole charge cable
https://www.aulro.com/afvb/images/imported/2016/06/721.jpghttps://www.aulro.com/afvb/images/imported/2016/06/722.jpg

That'll mostly work for you...

however I would suggest that in place of the very short cables for linking the 2 batteries in an emergancy if the main battery is flat you install a more permanant connection and a 100a relay with a remote access momentary, time delay or keyed switch to energise the relay from either the main or AUX battery. The logic being that if the main battery goes flat or drops a cell and the vehicle is locked you cant get into it to open the bonnet to connect the batteries.

In theory the ideal place for the relay is across the traxide sc80's cables to save you running extra cable.

[Milton477]

I have been meaning to ask, what is the significance of the LED on the new SC80? Mine flashes 4/5 reds then green steady for a couple of seconds, repeated when the vehicle has been standing for a while.

[drivesafe]

Hi Milton.

The operation of the LED in the new SC80 has been enhanced.

The old SC80 LED operation was a solid constant GREEN meant the isolator was on, and a flashing GREEN LED meant the isolator had shut down.

The new SC80 has a BiColour LED.

When you first install and power up the system, ( before your start your motor ) if the State of Charge ( SoC ) of the cranking battery is above 12.0v ( 05% SoC ) the SC80 will display a short GREEN flash every 2 seconds.

If the cranking battery is below 12.0v, then the SC80 will display a short RED flash, to indicate your cranking battery is in a low state.

Once you start your motor and the voltage at the cranking battery rises above 13.2v, the SC80 will display 2 short GREEN flashes for 15 seconds and then the SC80 and the LED will glow constantly.

NOTE after one minute, the LED will go to a DULL constant glow. More on this later.

When you turn your motor off, there will be a SURFACE charge in your batteries.

Once the SURFACE charge dissipates, the battery voltage settle and then the SC80 will indicate the SoC of the batteries by giving a number of RED flashes and one long GREEN pulse.

5 RED flashes means the batteries are between 85 and 100% SoC.

4 RED flashes and the batteries are between 70 and 85%

3 RED flashes means the batteries are between 60 and 70%

2 RED flashes indicates the batteries are between 50 and 60% and the SC80 is about to shut down.

Also, if the voltage at the SC80 exceeds 15..1v, the LED will glow a constant RED for 15 seconds.

If the voltage remains above 15.1v for more than 15 seconds, the SC80 shuts down and displays a continuos rapid flashing GREEN > RED > GREEN > RED.

The SC80 will not turn on again, until the voltage drops below 14.75, and it then returns to normal operations.

A Second version of the new SC80 will be available very shortly and this version, the SC80-M will be supplied with a small in-cab module with the BiColour LED in it and a couple of dip switches that will allow you to make a number of charges to the way the SC80 operates.

This is why the GRRED LED goes DULL 60 after the SC80 turns on, so as not to be a distraction at night.

[LRD414]

So rather than replace my less-than-two-year-old SC80 that I'm very happy with
Hmmmm, maybe I'll take that comment back. This new version sounds very good and subject to cost may be a worthwhile upgrade.

Scott

[Blknight.aus]

If you're going to put a solar system on or use a maintenance charger it will be.

[danialan]

I'm happy with my old style SC80 and seem to be missing the advantages of the new updated one?


The isolator specifically charges the AUXILIARY battery first, and then turns on to charge the cranking battery.
Surely priority should be given to the Start battery?

With my SC80, I simply connected the solar panels (and ctek charger) to the Start battery. So long both batteries are above 12V they both receive charge. If for whatever reason they drop below 12V and the isolator shuts down and separates the batteries, then in my case the solar (or ctek) would be charging the start battery and once it's up to 13.1V the isolator would rejoin them and charge both batteries again anyway.


Quite a few occasions have occurred where the cranking battery was flattened to the point you could not unlock the vehicle.
If both batteries have low voltage, and only limited charging is available from solar etc, surely it would be better to have that charge going first to the start battery, to have the maximum chance of unlocking and opening doors and bonnet? With charge going to the Auxillary battery, but voltage still below the isolator cut in, no charge would be going to the flat start battery. Wouldn't you still be in a situation of not being able to unlock the doors?


The isolator has been programmed to work this way so that if the cranking battery is not just flat, but has dropped a cell, the auxiliary battery will still be ?NEAR? fully charged and should still allow you to start the motor.
Surely there is an equal probability of the aux battery dropping a cell?

[Ben_Vapid]

I've got the old SC80 and installed a Projecta dual battery monitor to try get a better idea on the SoC, but it really only gives me voltage numbers. Any tips for using it to gauge the level of charge via the SC80, especially of the aux battery?

[Blknight.aus]

I'm happy with my old style SC80 and seem to be missing the advantages of the new updated one?


Surely priority should be given to the Start battery?

With my SC80, I simply connected the solar panels (and ctek charger) to the Start battery. So long both batteries are above 12V they both receive charge. If for whatever reason they drop below 12V and the isolator shuts down and separates the batteries, then in my case the solar (or ctek) would be charging the start battery and once it's up to 13.1V the isolator would rejoin them and charge both batteries again anyway.


If both batteries have low voltage, and only limited charging is available from solar etc, surely it would be better to have that charge going first to the start battery, to have the maximum chance of unlocking and opening doors and bonnet? With charge going to the Auxillary battery, but voltage still below the isolator cut in, no charge would be going to the flat start battery. Wouldn't you still be in a situation of not being able to unlock the doors?


Surely there is an equal probability of the aux battery dropping a cell?

the concept logic is to do with protecting the aux battery and allowing it to recieve the highest charge. As most people who install the traxide use it with the intent of a camping setup and a lot of people now do solar as well it gives priority of charge to the aux battery and when it is fully charged (near enough) then it connects up and cross charges to the main battery. this is to exploit "unused amps" that might be available from a camper trailer or caravan mounted solar/plug in charge system when the plug in aux batteries are nearly fully charged where the normal role for the traxide is to charge the aux batteries from the alternator.


with a good main battery, with the reversed setup even if the traxide remains disconnected and no charge goes into the start battery you should still be good for about 5 days without starting the engine and still be good for a start. What power is available for the aux systems from the panels all goes to those prolonging the life of your aux battery. this leaves your aux battery in a higher state of charge incase the main battery does die on you.

in a well used system the start battery is a little more likely to be the one that fails first especially if you do a lot of short run driving.

but lets not get confused here, the primary working of the traxide still works if you hook up to the main battery and it charges up to the point where the older traxide would connect the batteries, that still happens. With the new version it now cuts both ways. and heres the little extra kick for you..

if you wire it up right and use an external heavy duty anderson style connection for your aux battery connection without having the aux battery you can now use this to boost charge the main battery for an assisted start and power up the main battery powered systems even if its dropped a cell.

[drivesafe]

I've got the old SC80 and installed a Projecta dual battery monitor to try get a better idea on the SoC, but it really only gives me voltage numbers. Any tips for using it to gauge the level of charge via the SC80, especially of the aux battery?

Hi Ben, this should be of some help to you.


https://www.aulro.com/afvb/images/imported/2016/06/640.jpg

[drivesafe]

Hi danialan, just adding to what Dave has posted above, which is spot on the money.

With the original SC80, the batteries remain connected till the voltage dropped, through what ever reason, to 12.0v, then the isolator shut down.

With fully charged batteries, this could be 3 to 4 weeks after you last had the motor running. This was all good and well with vehicles used everyday but was a waste of battery power if you were leaving the vehicle used for long periods.

But this did meant that in most situations, if you connected an external power supply to the auxiliary battery, whether this is direct to the battery or via the Anderson plug at the rear, the two batteries were charged at the same time, AS LONG AS THE SC80 WAS STILL ON, when you connected the external power supply.

If, for what ever reason, the SC80 had shut down, the only way to charge the cranking battery was by applying a power source directly to the cranking battery.

With the new SC80, to avoid wasting battery power, if the vehicle is left for long periods, like the USI-160 and DT90 isolator, the new SC80 automatically shuts down after 72 hours, even though the batteries will most likely still be in a high state of charge.

In the vast majority of situations, this 72 hour TIME-OUT feature will do as intended and save battery power. But there will, and have been, situations where being able to REVERSE CHARGE the cranking battery would be advantageous. Like for people who may be storing their vehicle and only applying a maintenance charger every few weeks.

There is also the ever increasing situation where people are camping and charging their batteries using a generator/battery charger setup to charge their batteries once every few days.

In this type of situation, with the original SC80, if it had shut down, you had to connect direct to the cranking battery, to recharge it.

With the new SC80, this is no longer necessary, just plug the charger into the Anderson plug at the rear and you can now charge all the batteries.

NOTE, the OVER VOLTAGE protection has been added for these types of situations, to protect the cranking battery from erroneous charging supply voltages.

[Ben_Vapid]

Hi Ben, this should be of some help to you.


That does, thanks Tim!

[LRD414]

That does, thanks Tim!
I keep a print out of Tim's SoC table in the car for reference.
You probably already know but these voltages are resting, so you need to wait awhile after charging and/or running the vehicle so that the surface voltage/charge has gone.
Another related point is that the 12.7V will drop to 12.4V with ignition on but engine off for a healthy cranking battery.

(NOTE: all knowledge interpreted from Tim in another thread).

Cheers,
Scott

[Mungus]

, the only way to charge the cranking battery was by applying a power source directly to the cranking battery.

There is also the ever increasing situation where people are camping and charging their batteries using a generator/battery charger setup to charge their batteries once every few days.

In this type of situation, with the original SC80, if it had shut down, you had to connect direct to the cranking battery, to recharge it.

With the new SC80, this is no longer necessary, just plug the charger into the Anderson plug at the rear and you can now charge all the batteries.

.


Tim,
Please correct me if I am wrong, but;

When saying the Isolator/s has 'Shutdown', it is in the 'Isolated' state, as in the two batteries are disconnected?
When shutdown (batteries isolated), the cranking battery only, can be charged, be it from a generator/charger, solar via regulator etc., via the white 12S trailer plug?
When Shutdown (batteries isolated), the Aux. battery only, can be charged via your Anderson plug?
When batteries above 12.0V and Isolator is On (as in two batteries connected) charging via your Anderson plug will charge both batteries?
With batteries connected, charging to both batteries can still be done through the White 12S socket?
So if my assumptions above are correct, the newer SC-80 with reverse charge and future USI-160, whilst having advantages for certain scenarios, your current model USI-160 will be sufficient for my needs?

[letherm]

Another related point is that the 12.7V will drop to 12.4V with ignition on but engine off for a healthy cranking battery.

Just for clarification. When I get into the car and the voltmeter I have in the accessories port says 12.70 that's an accurate reading if I haven't yet turned the engine on or pressed the start button (ie switched on but engine not started). Just asking cause I know that opening the door wakes the beast up so to speak. :)

Martin

[rufusking]

I'll throw this into the mix. A while back I got in touch with Optima USA regarding the SOC voltages for Optima batteries and this is there response.

State of charge for an Optima deep-cycle battery, while not under a load:
100% charged is 13.18 Volts
75% charged is 12.69V discharge up to 750 times
50% charged is 12.28V discharge up to 600 times
25% charged is 11.72V discharge up to 450 times
0% charged is 11.27V discharge up to 300 times

I assume the difference in SOC voltages is due to the different style of battery.

[LRD414]

When I get into the car and the voltmeter I have in the accessories port says 12.70 that's an accurate reading if I haven't yet turned the engine on or pressed the start button (ie switched on but engine not started).
Martin, the 12.7 I stated earlier was a proxy for 100% SoC on a connected battery as per Tim's chart.

My actual figure is usually 12.5 from an accessory socket voltmeter, probably due to my lots-of-short-trips-in-city typical use.
When it "wakes up" voltage drops to 12.4

With your 12.7, is this in a socket connected to Traxide/aux or just factory/crank and does it stay at 12.7 without dropping?

Scott

[letherm]

Martin, the 12.7 I stated earlier was a proxy for 100% SoC on a connected battery as per Tim's chart.

My actual figure is usually 12.5 from an accessory socket voltmeter, probably due to my lots-of-short-trips-in-city typical use.
When it "wakes up" voltage drops to 12.4

With your 12.7, is this in a socket connected to Traxide/aux or just factory/crank and does it stay at 12.7 without dropping?

Scott
Hi Scott.

I just had a look and it's 12.3 ATM (I quoted 12.7 to not confuse the issue). It's factory/crank. Dropped for a moment to 10.9 when I started the engine and then ran up to 13.3 and settled at 13.1 with engine running. I let it close down and it only went down to 11.7 compared to the first time. The voltmeter doesn't show anything when the car has closed down. I too do mainly very short trips so I put it on a charger occasionally, probably every 2 months. I mean to do it monthly but don't get to it. :p

I bought the voltmeter to keep a bit of an eye on it but I'm not very knowledgeable about these things. At least Tim's chart gives me an idea so I can take preventative action if needed.


Martin

[LRD414]

We could be twins except mine is sitting a bit higher SoC initially and also sits higher when the car is running (at 14.1).

[rufusking]

Try measuring the voltage using the pins on the white trailer plug (pins 3 -ve, 4 +ve) first thing in the morning or after it has been sitting for a couple of hours (locked). Measure before you unlock it and wake it up. This should give a more accurate reading and SOC of the cranking battery.

[letherm]

We could be twins except mine is sitting a bit higher SoC initially and also sits higher when the car is running (at 14.1).

Mine does get into the 14 range sometimes but usually when I'm on the road instead of idling in the driveway. I haven't been constantly monitoring it, just looking now and then.

[drivesafe]

Tim,
Please correct me if I am wrong, but;

When saying the Isolator/s has 'Shutdown', it is in the 'Isolated' state, as in the two batteries are disconnected?
When shutdown (batteries isolated), the cranking battery only, can be charged, be it from a generator/charger, solar via regulator etc., via the white 12S trailer plug?
When Shutdown (batteries isolated), the Aux. battery only, can be charged via your Anderson plug?
When batteries above 12.0V and Isolator is On (as in two batteries connected) charging via your Anderson plug will charge both batteries?
With batteries connected, charging to both batteries can still be done through the White 12S socket?
So if my assumptions above are correct, the newer SC-80 with reverse charge and future USI-160, whilst having advantages for certain scenarios, your current model USI-160 will be sufficient for my needs?




Hi Mungus and the USI-160 in it's present form still has features not available in the new SC80.

The main one being the ability to select either SHARED Mode, as the SC80 operates, or IGNITION Mode.

And your "assumptions" are correct.

[drivesafe]

I'll throw this into the mix. A while back I got in touch with Optima USA regarding the SOC voltages for Optima batteries and this is there response.

State of charge for an Optima deep-cycle battery, while not under a load:
100% charged is 13.18 Volts
75% charged is 12.69V discharge up to 750 times
50% charged is 12.28V discharge up to 600 times
25% charged is 11.72V discharge up to 450 times
0% charged is 11.27V discharge up to 300 times

I assume the difference in SOC voltages is due to the different style of battery.
Yes and no, It has little to do with different battery types under normal use and is what is known as OPEN VOLTAGE readings.

My chart is pretty accurate for use with any type of lead acid battery, with a moderate load applied to it, like say a compressor fridge.

The voltage readings Optima supplied you are OPEN CIRCUIT voltage readings, and yes, this type of voltage reading will differ from one type of battery to another but is next to useless.

The reason a state that OPEN CIRCUIT voltage readings are next to useless is because they are only accurate once the battery has been sitting in a "No-Load/No-Charger" state for a least 24 hours.

this does not apply to an battery in a vehicle, because there is nearly always a load, even a very small load, applied to the batteries at all times, even when the motor is off.

Another problem with OPEN CIRCUIT voltage readings is that you must know that the battery is in good health when you take the readings otherwise, you may get a reading that shows the battery is fully charged, but the instant you apply a load, even something as small a load as a fridge, but the battery can go flat in a few minutes.