I'm working on best way to get a charge to my exped trailer. But I'm led to believe that my 2013 Facelift model Diesel 2.2 XS may have a smart alternator and therefore may need to consider a dc to dc charger. Also worth noting I have a 7 pin and not a 13 pin plug.

I'm after more of a trickle charge than a boost charge.

Any thoughts/ideas/suggestions greatly received.

Thanks.

You have a 7pin 'N' black socket.

What you would do best to fit is the 7pin 'S' grey socket, as used for towing caravans.

Do you know if there Is there a dedicated socket for 12s in the boot space like there is for 12n?

The LR wiring provides for either 12N and 12S or 13 pin. As already said, you'll need either a 12S socket or convert to 13 pin.

For a DC to DC trickle charger this Optimate DC to DC charger might do the trick - https://www.optimate.co.uk/products/optimate-dc

If you’re looking for something that can properly charge a trailer battery then this Votronic 20A charger is specifically designed to connect to a 13 pin trailer plug - https://www.votronic.de/index.php/en/produ...-1212-20-c

I have two 9amp Victron DC-DC chargers (they can be in parallel) in the boot, but I don't tow. They should be near the auxiliary battery so put it in the trailer. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Can you give a link to the 9 amp charger? I can only find their 30 amp one.

Lightwater wrote:

I have two 9amp Victron DC-DC chargers (they can be in parallel) in the boot, but I don't tow. They should be near the auxiliary battery so put it in the trailer.

Would you want to charge a trailer battery from the starter battery without the engine/alternator running? If so, the Optimate one I linked to above is designed to charge a small battery from a larger one without any alternator but it should, in theory, work if connected to a live pin of the trailer socket.

My charging requirements were to charge up 104ah of auxiliary batteries when moving between campsites. Usually a couple of hours driving & we move most days. I have set the DC output to 13.87 volts. A compromise between charging at a typical 14.4v & a trickle charge as I am not using the batteries all the time.. Typically I get 7 to 12 amps output for the 2 units & when the batteries are fully charged it's about 3 amps.

The size of DC-DC charger will depend on what you are trying to achieve. If it is a larger capacity you will need to run a dedicated power supply from the starter battery.


https://www.victronenergy.com/dc-dc-conver...#downloads

One DC-DC mounted on top of the other, MPPT above which has custom heat sinks front & back.

Click image to enlarge

An interesting setup. Thanks for the info. I had looked at a variety of chargers for a trailer battery and the Victron ones seemed better suited to a situation where you could directly connect the charger to the source battery with quite heavy duty cables which doesn’t really work for a detachable trailer with a battery.

The Votronic one is one of only a couple of devices that I found that are designed to connect to the trailer wiring and thus are designed not to draw more than about 20 amps maximum from the tow vehicle, i.e. within the rated capacity of the trailer wiring. Their 30 amp output model should be more than capable of charging any leisure or winch battery on a trailer. I plan to get the 20 amp version as my winch battery is only 22 AHr.

why not just use solar panels during 'stop' time to recharge batteries ? and split charger during 'running' ?

I have indeed got a small solar panel on the roof of the trailer which keeps the battery topped up when not in use and currently I use a voltage sensitive relay - split charge is a misnomer - to charge while towing. But this setup wouldn’t work with a Euro 6 engine - hence the plan to fit the Votronic unit in due course.

I have to set up the portable panels, it's not difficult, but I only need to do it if camping for longer periods. For 2 days I wouldn't bother unless it was a very short drive from the previous campsite. Our fridge uses 15ah per 24 hours. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

I guess it’s horse for courses. My needs are modest. If I’m using the trailer to take my car to an event the winch is only used a couple of times so the recharging requirement is minimal. The solar panel - only 20W - will probably top up the battery over the two or three days of the event, and the tow car will finish it off if necessary on the way home. KISS!