Battery charging from the car

[RoyForster]

Hi there,

I am going on my first CC rally at Easter.

As there will be no hook up, I will be using the vans battery for five days. I am concerned that the battery will be depleated when I need to use the caravan mover when I get home. (Sloping driveway and round the corner of the house)

The van has a inbuilt charger.

Does the vans battery recharge during the drive home?

If so do you have to tow the van with the vans on/off power switch in the ON position or does it not matter?

Many thanks

 

[ProfJohnL]

Hello Roy,

Your caravan instruction manual should tell you what you need to know.

Unfortunately we can't give you specific instructions as there are many different makes and models of distribution and switching systems used.

Perhaps if you were to be more specific about the make, model (and year) of caravan, and the make of switch panel you have if someone has the same they may be able to help you.

 

[Chris_374413356]

Hi Roy, plug the caravan in to the car and connect a multimeter (DC Volts) to the caravan battery. Get someone to start an rev the car engine and you should see the voltage rise to 14 volts (ish). That will tell you if the car charges the caravan battery whilst driving.

 

[Gafferbill]

...and if you do not have a multimeter you can repeat Chris's test but disconnect the caravan battery and wire a test bulb (12-volt) across the two battery leads.

The bulb should light up when you start your car engine to confirm charging is taking place when the battery is connected.

 

[waffler]

Welcome to rallying. The car should charge the battery but remember that the current used by the mover is huge and and you need a good battery with a good charge for it to work. First solution is to ask the stewards if there is a charging facility at the rally. If so take you charger and remove the battery for a few hours on the last but one day and give it a charge. If you are going to rally regularly I suggest you get a spare battery. You will find that the ralliers are helpful an if you express your worries someone will probably offer a generator to help you. (Offer to pay for fuel and when they refuse make a donation to the centre's charity.) Have a good time.

 

[GrahamDerby]

On my old Maxi i used to use what i think was called a split charger. I had a battery in the back of the car and when the car battery was charged it would trip over and charge the one in the back. Dont know if this type of thing is still around !!

 

[ProfJohnL]

In response to Waflers reply;

It is true that caravan movers will pull a large amperage from the battery, BUT, it is only for a relatively short length of time - in the order of a fraction of a second whilst the mover starts to turn its motors, but as soon as they are running the amount of current drops back to a far smaller amount.

In total most people only use about 1Ah of power when positioning the caravan, to put that into perspective, just one 12V-12W light fitting will use the same amount of power in just one hour!

Most caravan batteries provided they are in good condition should power a mover quite satisfactorily. Poor condition or low charge will affect the performance of a mover or may prevent it from working.