Charge 2 batteries

[mellon man]

Hi again
This question has probably been asked loads of times before:-
Want to connect a top battery charger for the winter have a leisure battery fitted but no electric hook up to connect to
If I connect to the main battery to charger will both charge or visa versa or do I need to charge separately ?

[g8dhe]

Its not possible to say directly it depends on what sort of Split Charge Relay is fitted.
If its a Voltage Sensitive Relay, then charging just the Starter battery should charge both, provided the charger voltage does exceed the voltage trip point for the Split charge Relay.
If the Split Charge Relay is controlled by the Ignition switch then no it won't allow the single charger to charge both batteries. You will have to move it between batteries every few days.

[Velocette]

Its not possible to say directly it depends on what sort of Split Charge Relay is fitted.
If its a Voltage Sensitive Relay, then charging just the Starter battery should charge both, provided the charger voltage does exceed the voltage trip point for the Split charge Relay.
If the Split Charge Relay is controlled by the Ignition switch then no it won't allow the single charger to charge both batteries. You will have to move it between batteries every few days.

Do you know which set up the Willinton kit uses?

[g8dhe]

Yup Willinton uses the Voltage Sensitive Relay, you will some times here it clicking after you have switched off the engine, so provided the charger will put the voltage up above that of the relay switching point it will charge both batteries, some small mtce. type chargers might not get the voltage high enough so if your not sure just check after a day or two, also be wary of the 3 stage/phase type chargers they can get confused when the relay pulls in halfway thru the process!

[Velocette]

Ta for that. I will bear it in mind. I have a 10A charger but it does have a little brain unfortunately so can sometimes refuse to play if it detects anything unexpected.

[mellon man]

Back to my original question - as my post has been hijacked by others

When I disconnect the positive on my leisure battery the warning alarm that sounds when your ignition keys are left in is silenced, don't know if that gives you experts any indication on what type of system is fitted ?

[g8dhe]

No that just indicates that the Sound Warning System is connected to the L/B, which is normal Top Left fuse;

It doesn't tell us anything about the type of charging system fitted to the L/B. Do you know who fitted the Split Charge relay ?

[Velocette]

Sorry I thought the point of a forum was that everyone can increase their knowledge. Carry on.

[mellon man]

[quote][/quote]Sorry I thought the point of a forum was that everyone can increase their knowledge. Carry on.

Nothing malicious meant by my comment just me being sarcastic sorry if I offended you

[Velocette]

Sorry I thought the point of a forum was that everyone can increase their knowledge. Carry on.

Nothing malicious meant by my comment just me being sarcastic sorry if I offended you

No worries, I am a bit on edge this morning, I should have let it go...

[mellon man]

Happy Days

[mellon man]

Thanks Supreme Being - what should I look for to find this split charger you speak about to see if there is any I D on it
I know the last owner did not have it fitted but before that no idea, feel they were D I Y'ers looking at the Heath Robinson type leisure battery clamp fitted

[g8dhe]

Humm, that doesn't sound promising if they have made DIY clamps

What your looking for is, a cable (30Amp minimum rating) that starts at the +ve terminal of the Starter battery, has a fuse close to the terminal, rating suited to the cable size, this will go to one of the switched terminals on a relay, from the other switched terminal on the relay a similar cable running to the Leisure battery again with a fuse close to the +ve terminal of the leisure battery - the TWO fuses are essential. Now looking at the relay in the middle, you should have a minimum of one wire that will go to earth/chassis, if that is all there is then it will be a Voltage Sensitive Relay (VSR) type (often these will have an LED to indicate operation). However if there is another wire running from the relay, back into the vehicle and towards the fuse panel or ignition switch then the chances are its an Ignition switched relay.

Its handy to know what sort of charging system you have as if you should ever flatten the Starter battery and you have the Ignition switched type then you can operate the Ignition switch to the normal position, and leave it for 10-20 minutes and you can put some charge back into the S/B! You can't do that with a VSR !

[mellon man]

Once again a real big thank you Mr Supreme Being (fair play you really know your stuff)
will take a look "weather permitting" and report back because I wish to fit a charger to the hook up that I am installing and NEED TO KNOW which battery to connect to.

[mellon man]

Stopped raining - all seems to fit your excellent description, the one wire does seem to go back into the cab so guess it's an Ignition switched relay. So you've probably already explained this but can I charge both batteries from one if so which one