Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[TheBoy]

Oh, I'm devastated, I can't tow a burger wagon. Oh well

It's not that you can't, just that your burgers will defrost in the 'fridge.

No, I'm pretty sure the man who lives in the glovebox that fixes everything said not to use for towing.

Camping is fine, as the fridge can plug into any of the 12v sockets scattered throughout the car.

[TD]

Cars that have this variable voltage alternators and risk running the van battery low during towing surely the option would be to leave the 12S socket not connected... 

Ok the fridge wont be working during towing but is that really necessary if you put some ice blocks in there for the journey. 

For vans like AA's with a power mover, surely if the van battery is fully charged at the beginning of each trip, then the battery must have enough juice to move the van at each end of the trip I would have thought....if you have a high enough power rated one 

[Andy B]

Cars that have this variable voltage alternators and risk running the van battery low during towing surely the option would be to leave the 12S socket not connected... 

Chances are if a car is new enough to have a 'smart' alternator, then it'll have a 13 pin socket

Ok the fridge wont be working during towing but is that really necessary if you put some ice blocks in there for the journey. 

Depends how long the journey is 

For vans like AA's with a power mover, surely if the van battery is fully charged at the beginning of each trip, then the battery must have enough juice to move the van at each end of the trip I would have thought....if you have a high enough power rated one 

that's part of the problem .... a 'flatter' battery won't move the caravan as far 

[Auto Addict]

The solution, I suppose, would be to isolate the caravan battery, from the cars 12v system.

That way it would be fully charged when I left home, get charged up again on site, and would still be fully charged when I got home.

This would allow me to use the mover to put it onto my drive.

The fridge could possibly be able to look after itself, I always get it cold before the star of a journey by running it on mains for 24 hrs plus.

Probably have to forget about taking frozen stuff with us.

Any ideas on a suitable relay to stop the feed going back to the car?

[Bigron]

Would a suitable (20 amp?) diode upset your car's charging system?

Ron.

[steve6367]

yes but you could still keep the battery at full charge and use the surplus amps to power everything else .

That's exactly what a conventional alternator does. Floating the battery at 13.8-14.4 V = keeping it fully charged and powering everything else from the alternator - all of the time the engine is running.

What a "smart" alternator does is to allow the engine ECU to reduce this voltage to perhaps 12.5V during cruising and acceleration conditions. Not low enough to seriously deplete the battery, but low enough that the battery will take no charge whatsoever unless it's pretty flat and, if it's fully charged, it will supply the car electrical loads. When braking, the voltage can be raised higher than the normal alternator output, to perhaps 15 volts or so, rapidly charging the battery and taking over all electrical load.

Don't forget that such a vehicle will probably be cursed with "stop-start" technology, so the loads on the battery are going to be quite high during normal driving as the battery repeatedly starts the engine and runs the accessories while the engine is stopped. By only replenishing such loads when the car is braking or when the battery does get low enough to cause concern, you save a little fuel.

Granted, the battery is going to keep getting cycled between partially discharged and fully charged, which will shorten its life, but since when have environmentalists been able to see the big picture?

I would love to know how much, but I suspect very very very little...

[Doctor Gollum]

Is there any room to fit a second, conventional, alternator to power the trailer?

[Jimbob]

You cant be the first to be trying to fix this?  Have the caravan club or similar got any advice?

[Andy B]

.......  Have the caravan club or similar got any advice?

You must be joking ..... they cant manage a decent web site

[TheBoy]

Does the fridge really need to be cold upon arrival?

Get the fridge powered up on arrival, nip to supermarket for supplies, it should be cool by the time you're back.

This caravanning malarkey seems a hell of a lot more effort than camping, for the gain of being more cramped, restricted on travel speed/distance, drink huge amounts of fuel, and storaing the bloody thing

[Auto Addict]

Does the fridge really need to be cold upon arrival?

Get the fridge powered up on arrival, nip to supermarket for supplies, it should be cool by the time you're back.
This caravanning malarkey seems a hell of a lot more effort than camping, for the gain of being more cramped, restricted on travel speed/distance, drink huge amounts of fuel, and storaing the bloody thing

Fridge is not really a problem, we get it cold before we set off, and will probably get the odd current from the alternator on the journey.

The main problem would be the caravan battery draining to the same voltage as the car battery.

I think the simple solution would be to fit a battery isolator switch (caravan battery end) to stop this happening as you don't need the 12v system on the caravan whilst towing.

Err cramped? Don't think so, fixed bed, all mod cons, hot & cold water on tap, waste straight into drain, central heating if it gets cold, own spacious shower, loads of storage space, never gets damp in the pouring rain, I could go on............

[Andy B]

   ....
 I could go on............

... and toilet for those night time visits 

[Auto Addict]

   ....
 I could go on............

... and toilet for those night time visits 

I said I could go on

[Auto Addict]

   ....
 I could go on............

... and toilet for those night time visits 

I said I could go on

Don't you just love watching people putting up/taking down large tents in the pouring rain from the comfort of your caravan

[TD]

A quick google and I found this article.....tho they aint cheap...

http://www.12voltplanet.co.uk/battery-to-battery-chargers.html