How to charge battery in camper as well as 2nd onboard battery

[POD]

I find myself with a new dilemma regarding auxilliary battery charging. I've bought a used Trayon camper that has a lithium battery installed. The previous owner seems to me to have connected the electrical system in all sorts of wrong ways; there's a 240v battery charger wired in so that it charges the lithium battery when 240v shore power is plugged in, however it is not a lithium charger (has no lithium mode) so I'm keen to do better.
I have two batteries in the Defender; the standard (wet lead/acid) starting battery plus an optima yellowtop that is the auxiliary, runs the engel fridge which I plan to continue to use in the back seat area. I have an early generation dual battery controller that has done a stirling job but adding a third, lithium battery to the mix now complicates things.

I have been using a solar panel that I plug into an anderson plug by the towbar, to charge the auxiliary whilst camping. This works a treat for the 2 vehicle batteries. The Trayon also has an anderson plug input connected direct to the battery.

I considered getting rid of the 2nd battery in the car so I am back to 2 batteries, but I want to be able to keep using the fridge in the car.
Considered deleting the battery in the camper, but it has a fridge too and I want to be able to run the fridge if I leave the camper free-standing.

What is going to be the best option to be able to run 3 batteries, one of which is a lithium, and be able to charge from alternator and solar? I've looked at the Ctek D250se but unsure if it will allow me to charge 3 batteries of different types? Would adding the ctek dc-dc charger to the camper, whilst leaving my existing onboard charging system as-is, work?

[trout1105]

As far as I am aware you will need a DC to DC charger to keep your lithium battery in the camper up to scratch (talk to Tim about this).
Also If you want to have the camper "Free standing" consider adding solar to the mix and run it through the DC to DC charger in the camper as most of these units are solar friendly [thumbsupbig]

[drivesafe]

Hi POD, how old is your defender?

[W&KO]

I’m thinking, leave your existing VSR that done a sterling job so far between your starter and optima

I’d than install a DC-DC in the camper…..nearly all would have two inputs for alternator and solar.

I would assume you’d have a Anderson between car and camper

I run a DC-DC but run the fixed solar through a separate controller, I do have the ability to plug portable solar into the DC-DC if required. Oh I only have start battery and one lithium. I didn’t bother installing an A/C charger.

[PhilipA]

I have similar setup to you in my D2 .
AGM house battery with simple solenoid, fridge in back and caravan.
I fitted a Renolgy 20 amp DC DC charger in the van.
I also have a 3 way fridge in the van and both fridge and lithium in van run from the solenoid through 4 gauge to the back of the car then 8 gauge to the fridge and Renolgy.
I control the Renolgy and fridge through a 200 amp relay triggered by a wire from accessory , in case I want to leave the charger and fridge on car battery power for some reason.
regards PhilipA

[Pedro_The_Swift]

A different view,,
any normal charger will still do lithium, just not very well. The money you spend on a lithium charger would be better spent on more solar.
This phobia we have about getting batts to 100% is an ancient lead acid hangup that is just not necessary with Lithium, in fact its best for Lithium to NOT reach 100

[drivesafe]

A different view,,
any normal charger will still do lithium, just not very well. The money you spend on a lithium charger would be better spent on more solar.
This phobia we have about getting batts to 100% is an ancient lead acid hangup that is just not necessary with Lithium, in fact its best for Lithium to NOT reach 100
This is why I want to know what defender POD has.

If it's an older one ( pre 2004 ) he can actually use nothing more than a standard solenoid, wire to his ignition switch, and leave everything else as is.

His alternator can safely charge the lithium battery with out having to spend up on a DC/DC charger.

Would save money and his lithium would charge faster.

[W&KO]

A different view,,
any normal charger will still do lithium, just not very well. The money you spend on a lithium charger would be better spent on more solar.
This phobia we have about getting batts to 100% is an ancient lead acid hangup that is just not necessary with Lithium, in fact its best for Lithium to NOT reach 100

By default our lithium returns to 100% nearly everyday…….i know in house setup they restrict full charge but in a tourer I don’t see it’s anywhere near as important. Our capacity hasn’t dropped yet, going off what the app tells me.

while it’s doesn’t bother us if we don’t see 100% on multi day stays I still prefer seeing 100% at some stage during the day, that way we have no limitation for our evening cook up on tie induction hotplate.

It seem ls lithium users are now more focus on how little they can use each day, like bragging rites.

Us, we use whatever is available in the tank and replace it the next day……traveller ask what did we get down, generally I have no idea.

[towe0609]

Hi POD, how old is your defender? I'm sure he'll be along soon, but it's a PUMA Defender.

[POD]

I'm sure he'll be along soon, but it's a PUMA Defender.

Yes 2008 model.
Thanks for the replies. I'll look into the chargers suggested. Thinking about it I can't see any reason to change the setup I have on the vehicle as I can input solar and it all works well, but seems i'll need a DC-DC charger to charge the camper battery from the vehicle. What about battery maintenance when the camper is not in use though? Do people keep their caravans etc plugged in to a mains charger all the time?

[drivesafe]

Yes 2008 model.
Thanks for the replies. I'll look into the chargers suggested. Thinking about it I can't see any reason to change the setup I have on the vehicle as I can input solar and it all works well, but seems i'll need a DC-DC charger to charge the camper battery from the vehicle. What about battery maintenance when the camper is not in use though? Do people keep their caravans etc plugged in to a mains charger all the time?
This will depend on how often you use the van.

Lithium batteries can be left in a charged state for many months, up to a year and need no maintenance.

With adding a DC/DC to the van, because you have a SMART alternator in your Puma, you will need to source an IGNITION circuit in the defender and run this to the IGNITION input on the DC/DC.

Not sure whether your Puma comes with a Black ( N12 ) and White ( S12 ) sockets on the back.

If you have the two socket, then in the WHITE socket is the FRIDE circuit. Run a connection from this to your DC/DC IGNITION input.

JOB DONE.

SPECIAL NOTE, do NOT set the DC/DC to VOLTAGE sense as this can result in very pour charging of the lithium battery because of the way your SMART alternator works.

[trout1105]

Do people keep their caravans etc plugged in to a mains charger all the time?

I have always had solar panels on the roof of my vans/campers that maintain the batteries in them perfectly when they have been parked up.
IF you don't have solar on your camper you can always set up a portable panel for the camper when not in use[thumbsupbig]

[PWat]

I would recommend adding some solar panels to the camper: we have a 100A/hr lithium, 300w of solar and don't need to use the car to charge the battery. (I've actually done it the other way round - connected the car's aux battery to the solar to top it up when we've been parked for a few days.) Solar panels on the roof of the camper will also provide some extra insulation from the sun, a bit like a safari roof.

One thing I've noticed when traveling is that people tend to under-spec their fixed solar panels and then need to supplement with fiddly fold-up ones - do it properly the first time and only do it once!

[POD]

I have a bit of a different philosophy with my solar panels- I like to camp in the shade and have the panel on at least 10 meters of cable so it can be on it's pat malone in the sun. Solar panels on the roof of the Trayon would be a bit pointless as the roof flips over and points to the ground when camping! I've used a 120w portable panel for some years and generally find the overnight battery drain from the fridge and lights has been recharged by around 9am, scored a second, larger panel with the camper purchase (about 200w I think). One thought has been to make a temporary mount for the portable panels so they pay their way whilst travelling, but we also carry a canoe which casts quite a shadow over the length of the vehicle.

[towe0609]

Peter - one feature to consider ... I have a Ctek D250S and run my portable solar into it. Something it does not do is charge the 'starter' battery, even if the 'house' battery is fully charged. I was frustrated by that for many years.

I recently acquired a second hand Ctek smart pass and one of the side benefits of that is that it will direct charge back to the 'starter' battery - so this shortcoming is no more.

I only carry 1 portable panel, and want it to be able to charge the house battery, and when that's full, also charge the starter. If you continue with just a single source of solar, then you may want to make sure that whatever does the 'isolating' of your starter and house batteries allows charge to flow to the car to keep the battery servicing the car fridge in tip top shape.

[POD]

It really is first world problems, isn't it- worrying about how I'm going to use my two portable solar panels to charge my 3 batteries to run my 2 fridges whilst holidaying.....:)

I've seen the smartpass gizmo advertised with the Ctek dc-dc charger, was wondering what the point of it was so that makes sense now. $800-ish worth of gadgets to manage the batteries is a bit daunting though. I guess there's no reason why I can't keep doing what I've always done with the 2 batteries in the car 9i.e. existing dual-battery management plus existing solar), and add the second solar panel and the dc-dc charger for the camper. Or am I missing something?

[trout1105]

What are you running in the camper?
If its only a fridge and a few lights maybe you can get away with simply using an MPPT controller with a lithium profile to keep the lithium battery in it topped up via your mobile solar panel alone [thumbsupbig]

[towe0609]

It really is first world problems, isn't it- worrying about how I'm going to use my two portable solar panels to charge my 3 batteries to run my 2 fridges whilst holidaying.....:)

I've seen the smartpass gizmo advertised with the Ctek dc-dc charger, was wondering what the point of it was so that makes sense now. $800-ish worth of gadgets to manage the batteries is a bit daunting though. I guess there's no reason why I can't keep doing what I've always done with the 2 batteries in the car 9i.e. existing dual-battery management plus existing solar), and add the second solar panel and the dc-dc charger for the camper. Or am I missing something?

I'm no advocate for the Ctek combo ... and certainly not for RRP ... I only bought the smart pass because I came across a second hand one for $100 and it solved my problem (as well as speeding up charging from the Alternator) and it fitted in with what I already had (I wish I'd never bought it but that's another story). I'm sure there are cheaper and better ways to solve your problem ... I just wanted to highlight that if you were only going to take 1 solar panel, then you'd want to consider how its output is made available to both your camper and car battery systems given the draw of the fridges.

[POD]

What are you running in the camper?
If its only a fridge and a few lights maybe you can get away with simply using an MPPT controller with a lithium profile to keep the lithium battery in it topped up via your mobile solar panel alone [thumbsupbig]

The electrical loads in the camper are fridge, some LED lights, diesel heater, water pump, water heater (gas water heater so presumably very low electrical load for ignition).
Times when charging with just the solar is not ideal are when on the move for a day (or multiple days) and camping at night, not much opportunity for putting out the portable panels and need tp take advantage of the alternator. As mentioned, I carry a large canoe on many trips so the roof is shaded.

STOP PRESS I discovered this afternoon that the battery in the camper is in fact an AGM; seller stated it was lithium and it was mounted with the label facing a bulkhead. Turned it around today and it's a chinese AGM! At least this means the 240v charger he had set up is compatible with it. I think I still need a dc-dc charger though.

[drivesafe]

Hi again POD, if your current setup adequately charges your auxiliary battery, then as long as you have decent sized cabling running from your auxiliary battery to the house battery in the van, then there is a very good chance that is all you will need .

This will allow you to use both the auxiliary and house battery together while camping, if you keep the vehicle and van connected.

Then when driving, you should be able to recharge both batteries.

This setup will also allow you to charge both batteries with your solar setup while camping.

Just a suggestion and might be worth testing.

[POD]

Hi again POD, if your current setup adequately charges your auxiliary battery, then as long as you have decent sized cabling running from your auxiliary battery to the house battery in the van, then there is a very good chance that is all you will need .

This will allow you to use both the auxiliary and house battery together while camping, if you keep the vehicle and van connected.

Then when driving, you should be able to recharge both batteries.

This setup will also allow you to charge both batteries with your solar setup while camping.

Just a suggestion and might be worth testing.

That's interesting, I thought that the whole idea behind dual-battery isolators was that you couldn't just hook up two batteries in parallel and expect to charge both? Long time since I last looked into this and it is way outside my expertise. it would certainly simplify things if I can just connect the camper into the vehicle via the (already insitu) anderson plugs.

[drivesafe]

That's interesting, I thought that the whole idea behind dual-battery isolators was that you couldn't just hook up two batteries in parallel and expect to charge both?
Hi POD and yes there is a lot of B/S out there.

You can connect any type of lead acid battery with any other type of lead acid battery in PARALLEL. ( totally different story with batteries connected in SERIES )

Plus, when charging with an alternator, all the batteries will charge pretty well independently of each other and if you drive long enough, all the batteries can be fully charged.

[oldie]

Hi Pod

We have had a Trayon (#715) on our 110 cab chas for 11 years now and have found it wonderful. We have done over 100,000 km mostly in the outback and it has been a great set up.
I added a simple battery isolator to the truck and a simple dc-dc to the "Box" and that worked well for many years. I then swapped out the 3 way fridge to a compressor one and added a light weight semi flexible solar panel to the roof to allow charging while pulled up but not camping. This was fastened with wing nuts so that after we opened the Box up, it was easy to remove the solar panel and put it out in the sun. This charged the battery through an older PWM regulator.
After the 2nd SLA battery died I decided to go lithium (200 ah ) and also moved the batteries into the back left hand cupboard. The people at Itek told me I would not need to change any of the other parts of my system.
The Box is stored in a shed so no solar. I have found I need to put a charger on the batteries every couple of months as it seems the various amp and volt meters take a bit out.
We sometimes go camping with our kids and grandkids and we act as "Mother ship" often running 3 fridges for up to 4 days using an additional portable solar panel. All good.
Hope you get as much enjoyment from your Trayon as we have.
Keith, Oldie

[prelude]

Peter - one feature to consider ... I have a Ctek D250S and run my portable solar into it. Something it does not do is charge the 'starter' battery, even if the 'house' battery is fully charged. I was frustrated by that for many years.

I recently acquired a second hand Ctek smart pass and one of the side benefits of that is that it will direct charge back to the 'starter' battery - so this shortcoming is no more.

I only carry 1 portable panel, and want it to be able to charge the house battery, and when that's full, also charge the starter. If you continue with just a single source of solar, then you may want to make sure that whatever does the 'isolating' of your starter and house batteries allows charge to flow to the car to keep the battery servicing the car fridge in tip top shape.

Personally, I am very pleased with the CTEK combo. It costs a heck of a lot less then a certain red colored brand and can do practically the same. The D250SE I have does charge the starter battery from solar, eventually. When the aux battery has been fully charged and is in float operation basically then the solar input will have nothing to do basically and charge the starter battery every 3 seconds. The smartpass does the same but the D250 should do this as well when stand alone.

-P

[POD]

I've bought the D250se, have not managed to get it installed yet. I have a fair bit of work to do to marry the Defender to the Trayon camper (like building a tray to put it on) so might be a while before I get to try the setup out properly, but it appears that it should serve the purpose.