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

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Originally Posted by POD

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?

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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.

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

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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]

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!

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.

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.

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?

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]

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Originally Posted by 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?

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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.

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Originally Posted by 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]

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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.

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.