charging battery

[joner818]

how does your car charge battery on caravan does trickle charge or keep giving short bursts of charge as mine does battery was flat and volt meter in van was going up and down on the burst of power but battery did not charge how long till it would be charged when driving

 

[rayc]

simon, this is only a guess but it is possible that there is a problem with the car supply . The bursts that you see could be due to the relay in the car, which controls the feed to the fridge on pins 6 & 7 of the 12S socket. The fridge supply also switches a habitation relay in the van which will feed the supply from the car on pins 4 & 3 of the 12S to charge the battery or supply the van 12v when engine not running. The habitation relay could be dropping in and out as a result of the relay in the car beeing set too tight. Does the bursting stop if the car revs are increased?

 

[RogerL]

"Short bursts" sounds like relay chatter - some relays can be adjusted.

 

[antrimboy]

Ray- I think you'll find that the fridge supply and battery charging are on two completely separate relays. The fridge relay being in the car, and the habitation relay for the internal 12v./battery charging is in the 'van.This of-course is for post 1998 caravans.

Pre 1998 'vans have their batteries charged via pins 2 & 3 on the 12S socket with the relay being in the car.

Simon- the supply should be a steady flow, instead of the pulsed flow that you are getting, and if the battery is dead flat, you would be better trying to charge it with a mains charger initially.

 

[rayc]

Eddie, thanks for the info BUT I think you will find they are inter related. The fridge supply on pin 6(+) and pin 7(-) feed the fridge but also operates the caravan habitation relay. The permanent feed / battery charging on pin 4(+) and pin 3(-) is switched by the habitation relay either to the battery when the engine is running or to the van 12v system when it isn't.

If there were no fridge supply on pin 6 & 7 then the habitation relay would not operate and the supply on pin 4 &3 would never be sent to the van battery but remain being fed to the van 12v system.

 

[antrimboy]

Many thanks for that Ray. I wasn't aware that the hab. relay received a supply from the fridge feed. It's definitely one to remember in case of future needs.

 

[rayc]

Many thanks for that Ray. I wasn't aware that the hab. relay received a supply from the fridge feed. It's definitely one to remember in case of future needs.

Eddie, many thanks. Out of interest in these days of a voltage operated relay in the car it is fairly common for the adjuster to be set too tight which leads to "pulsing2 as the relay operates and then the fridge starts to draw current and this causes a volts drop which drops the relay out and the cycle is repeated. I have found that setting the relay so that it is operated with the engine ticking over with the haedlights on is normally ok. The other problem with the relays is they hang on when the engine is swiched off. People going into the van at a stop find the lights do not work. If this happens the trick is to pull out the 12S plug which drops the habitation relay out.

 

[joner818]

simon, this is only a guess but it is possible that there is a problem with the car supply . The bursts that you see could be due to the relay in the car, which controls the feed to the fridge on pins 6 & 7 of the 12S socket. The fridge supply also switches a habitation relay in the van which will feed the supply from the car on pins 4 & 3 of the 12S to charge the battery or supply the van 12v when engine not running. The habitation relay could be dropping in and out as a result of the relay in the car beeing set too tight. Does the bursting stop if the car revs are increased?

dont no ray as did not rev it car is in storage at moment so took bat off and was flat

 

[joner818]

"Short bursts" sounds like relay chatter - some relays can be adjusted.

i will have to wiat till wife gets home with car if the relay is changable how do i set it high or low