Adding a third battery.

[TheDocAUS]

Kings 160w panel on roof. Cannot remember if solar blanket is 160w or 200w, as I did not need to use it on my last Outback trip. I have a Bushman fridge which has a low draw. I use battery power for key gear like fridge, camera batteries and pie oven. No coffee machines, inverters, etc.

I run Anderson plugs for the fridge from the aux battery.

The CTEK250SE can charge the main and aux batteries from solar (aux battery has priority).

@ninetubes installed a lithium as his aux battery, he maybe able to comment.

From what you describe a 30 minute drive each day should be enough to keep the Moll batteries running fine, assuming you are also using solar.

I have come to realise the CTEK and the batteries can charge at very high rates, with no issues so far. In my Patrol I had to change batteries every 2-3 years, very hot under the bonnet in a Patrol. So if I get 3.5 years from the IG I will be happy.

When parked keep the doors shut and use a Faraday bag for the remotes, so the car cannot see them and drain the battery. Faraday bags are easy to get from eBay. I have not tested my Faraday bag yet with the remotes, but it should work. I found keeping the doors shut worked on my trip

 

[Rok_Dr]

Thanks for your comments @TheDocAUS.

Interesting that you have found the onboard power sufficient. What's the watts output of your solar panel? and what's the amp draw of your fridge?

I have noticed significant depletion of the battery just by opening and closing doors without running the fridge or any other load drawing consumers from the onboard batteries. I have a 200W solar blanket that I have fed directly to the Crank battery (because that is where all the loads are coming from), via a 20A Victron MPPT controller. This set-up seems to work ok but not sure what is happening to the second battery. I probably should have got the CTEK250SE instead for solar input as I presume that would balance both batteries from solar?

I run my 225 watt solar panel through a Victron MPPT 75/15 solar controller and its output voltage is sufficient to open the smartpass to start charging the Aux battery as well as the starter. Voltage cut in/outs are in my earlier post. As you already have a Victron solar controller there is no practical advantage to going to a Ctek D250se. Plus if your solar panel VOC is >23v, the Ctek D250SE will not support your panels. That is why I went Victron.

Noting @TheDocAUS's comment above a small tin will achieve the same effect as a fancy faraday bag at minimal or no cost.

I have seen the system show a charge rate of 189A when the battery is under 50% SoC (and have a photo to prove it) after sitting camped for 3 days, it still started no problem, but I will never do that again. I presume that charge rate is just to the primary battery, regardless, it is a healthy rate so I wonder what advantage the 250SE DC-DC provides over the current system other than solar input? Obviously a lithium service battery would not be able to be charged at that higher rate so a DC-DC would be needed in that case.

The cars system only monitors the state of charge for the starter battery. There is no monitoring of the Aux battery. You'll need to install a shunt on the Aux battery to monitor its SOC, or a cheap bluetooth monitor if you only want to track voltage. You're right for the standard setup the DS250Se only effectiverly adds a solar input.

I like the idea of using the already onboard system, but I've been concerned (which is probably also why many are sceptical) about killing both batteries, particularly with potentially deep discharging/charging often. I carry a lithium jump starter, but relying on that often seems also dangerous. Hence my thought to upgrade the service battery to a larger Ah lithium to expand total Ah capacity already onboard so I don't need to be checking the SoC so often . However, not sure what the implications will be to the system's function. i.e. Would a lithium still assist cranking if needed? and will the trickle charge of crank battery still work?

The advice I've received (Ctek via Ineos) is that the smartpass will disconnect the Aux battery when its SOC is <50%. I have not tested this, but periodic checking of the Aux battery with a volt meter over a number of days and not starting the car doesn't show much voltage drop.

Just for context... I have been using a similar, but smaller arrangement to yours, I use a pair of 40Ah Companion power stations in rotation to run the fridge, which has worked to this point... but it is close to the wire. One 40Ah will run my current fridge for about 24hours but if I upgrade to a bigger fridge (which I need to do for longer trips) and add Starlink, plus any other tech consumers that my daughter insists on bringing , I'm going to struggle particularly if solar input dips, so I need to increase capacity. I've looked at battery boxes but they are BIG! and space is of a premium on longer trips (I travel with swag/RTT only). I had identified an area beside the fridge to attempt building my own battery compartment, but wondered if there is a way to better utilise the Ineos system and not have to add a large 3rd battery.

Appreciate others thoughts, particularly if anyone has (and I'm sure people have) changed over to a lithium service battery.

Maybe add an extra solar panel. On my Camper trailer I use 2, 225w panels. It has 2x100 amp hr lithium batteries and after 3 days running with one panel, the combined SOC was down to 35%. Adding the second panel resulted in everything being fully charged in 1/2 a day. Major power draw in the trailer was the fridge @ 5 amps when running, plus the days were warm. At the end of the day having a large battery bank is useless if your charging capacity is less that your daily draw.

So as a first step I'd strongly recommend working out what your power usage actually will be. Once you know what you use in a day then you can design a charging system to suit. There are a few spreadsheets on line that you can use.

I don't think changing over to a lithium starter battery is feasible, principally because the vehicles battery management system charging profile can't be modified for Li. Changing the Auxiliary battery is possible but my understanding is the smartpass by itself it doesn't support different charging profiles and mixed battery chemistries. You'd need to add a D250SE (keeping in mind its solar VOC limitation) and run the vehicle input through it (with a 20amp charge limitaiton) or better still rip it out and fit some redarc or victron gear. Also keep in mind that not all Li batteries will be able to support the Amp draw needed to start a vehicle.

Cheers
Steve

 

[blighty001]

I run my 225 watt solar panel through a Victron MPPT 75/15 solar controller and its output voltage is sufficient to open the smartpass to start charging the Aux battery as well as the starter. Voltage cut in/outs are in my earlier post. As you already have a Victron solar controller there is no practical advantage to going to a Ctek D250se. Plus if your solar panel VOC is >23v, the Ctek D250SE will not support your panels. That is why I went Victron.

Noting @TheDocAUS's comment above a small tin will achieve the same effect as a fancy faraday bag at minimal or no cost.


The cars system only monitors the state of charge for the starter battery. There is no monitoring of the Aux battery. You'll need to install a shunt on the Aux battery to monitor its SOC, or a cheap bluetooth monitor if you only want to track voltage. You're right for the standard setup the DS250Se only effectiverly adds a solar input.



The advice I've received (Ctek via Ineos) is that the smartpass will disconnect the Aux battery when its SOC is <50%. I have not tested this, but periodic checking of the Aux battery with a volt meter over a number of days and not starting the car doesn't show much voltage drop.


Maybe add an extra solar panel. On my Camper trailer I use 2, 225w panels. It has 2x100 amp hr lithium batteries and after 3 days running with one panel, the combined SOC was down to 35%. Adding the second panel resulted in everything being fully charged in 1/2 a day. Major power draw in the trailer was the fridge @ 5 amps when running, plus the days were warm. At the end of the day having a large battery bank is useless if your charging capacity is less that your daily draw.

So as a first step I'd strongly recommend working out what your power usage actually will be. Once you know what you use in a day then you can design a charging system to suit. There are a few spreadsheets on line that you can use.

I don't think changing over to a lithium starter battery is feasible, principally because the vehicles battery management system charging profile can't be modified for Li. Changing the Auxiliary battery is possible but my understanding is the smartpass by itself it doesn't support different charging profiles and mixed battery chemistries. You'd need to add a D250SE (keeping in mind its solar VOC limitation) and run the vehicle input through it (with a 20amp charge limitaiton) or better still rip it out and fit some redarc or victron gear. Also keep in mind that not all Li batteries will be able to support the Amp draw needed to start a vehicle.

Cheers
Steve

Thanks for sharing your thoughts @Rok_Dr Valuable info and good advice.

Jake from Challenge batteries in Osborne park (WA) has been really helpful, he talked me into the Victron mppt controller because it can take higher VoC when I get multiple solar sources I can series them for longer charging days so it was good advice. I’d forgotten the 250SE is limited in that regard. I may continue with Victron Orion dc-dc when I decide how I'm going to do the upgrade.

Good advice to get a good understanding of daily consumption and design capacity and charging to suit. Makes perfect sense.

I love the tip about the Faraday bag or better still a small tin. The Gren starts making noises when I simple walk by with the key in my pocket so it's certainly doing something... consuming those Amps.

Lots to digest and consider. Thanks again.

 

[Rok_Dr]

Thanks for sharing your thoughts @Rok_Dr Valuable info and good advice.

Jake from Challenge batteries in Osborne park (WA) has been really helpful, he talked me into the Victron mppt controller because it can take higher VoC when I get multiple solar sources I can series them for longer charging days so it was good advice. I’d forgotten the 250SE is limited in that regard. I may continue with Victron Orion dc-dc when I decide how I'm going to do the upgrade.

Good advice to get a good understanding of daily consumption and design capacity and charging to suit. Makes perfect sense.

I love the tip about the Faraday bag or better still a small tin. The Gren starts making noises when I simple walk by with the key in my pocket so it's certainly doing something... consuming those Amps.

Lots to digest and consider. Thanks again.

I've used Challenge batteries in the past and they have a good reputation so you are in good hands there.