Battery charging with a Willinton Kit

[keycare]

I have had a bit of a poke around but can't seem to find any answers...

I have a Willinton Kit installed and I need to charge my starter battery. I have a meaty CTEK charger mainly for charging and topping up the Leisure battery between trips as the Bongo isn't used every day.

If I connect the CTEK to the starter battery, the Willinton Kit keeps switching. Presumably because the charger pulse charges the battery. Is this likely to damage the Willinton kit? I imagine it will wear our the solenoid after a while. So that being said, should I disconnect the willinton kit from the start battery when charging? Or is there an easier way to keep both batteries topped up through the winter months?

Cheers.

[g8dhe]

How often is it pulsing and for how long is each pulse ? The relays are good for a LARGE number of operations, but if you don't need to charge the L/B the easiest way to stop it would be to just remove the fuse nearest the S/B going to the Willinton relay.

[madmile]

Alternatively, you could charge the leisure battery first, then charge the starter battery. The relay clicks on and off as the low state of charge of the leisure battery drops the main battery below the cut off voltage pretty much instantly, so you get a clicking relay.
If the leisure battery has just been brought up to a reasonable state of charge, and you swap the charger to the starter battery - When the relay opens, the likelyhood is that it will stay open, and you can charge both batteries from there on via the split relay.
I quite often do this if we have a van in the workshop for a while and want to keep the batteries topped up.

[dave_aber]

Do you have mains hook-up installed as well, i.e. a fixed charger / power supply wired to the L/B?

If so, then you can exploit a (probably unintentional) feature of the Willinton kit.

Connect up your mains hook-up. L/B Voltage goes to +13.8v or similar. Start the engine, main battery voltage rises to 13.8v or similar, and the willinton relay closes. Stop the engine. Since the Willinton kit relay is closed at this point, the main battery voltage will be the same as the L/B, around 13.8v or so. In this state, the Willinton kit will hold itself 'on' since the L/B voltage never drops below the switching threshold - hence both batteries will charge in parallel.

[cozmo1589]

In my experience and as a rule of thumb, when charging a car battery it is advisable to disconnect it from the cars electrical system.
Only just purchased a new vehicle battery charger at the weekend and it is written in the instruction/guidine booklet that was in the box.

[mikexgough]

Do you have mains hook-up installed as well, i.e. a fixed charger / power supply wired to the L/B?

If so, then you can exploit a (probably unintentional) feature of the Willinton kit.

Connect up your mains hook-up. L/B Voltage goes to +13.8v or similar. Start the engine, main battery voltage rises to 13.8v or similar, and the willinton relay closes. Stop the engine. Since the Willinton kit relay is closed at this point, the main battery voltage will be the same as the L/B, around 13.8v or so. In this state, the Willinton kit will hold itself 'on' since the L/B voltage never drops below the switching threshold - hence both batteries will charge in parallel.

That does work well...... if you connect your mains as soon as you arrive home.....then the above plays out easily...as the Willinton will still be "live"..

[hembramacho]

Do you have mains hook-up installed as well, i.e. a fixed charger / power supply wired to the L/B?

If so, then you can exploit a (probably unintentional) feature of the Willinton kit.

Connect up your mains hook-up. L/B Voltage goes to +13.8v or similar. Start the engine, main battery voltage rises to 13.8v or similar, and the willinton relay closes. Stop the engine. Since the Willinton kit relay is closed at this point, the main battery voltage will be the same as the L/B, around 13.8v or so. In this state, the Willinton kit will hold itself 'on' since the L/B voltage never drops below the switching threshold - hence both batteries will charge in parallel.

What a great tip - cheers for that. I was always worried that if I had my LB on charge via my CTEK charger, and then started the engine, the extra charge then given from the Willinton might be too much and damage the battery. Shows my ignorance really. I'll give that a go.
I have in the past though charged my starter battery with the CTEK, and when it gets to a certain voltage the Willinton starts charging the LB too via the relay clicking on/off for a bit before finally staying on - is this still OK to do also?

Cheers

Andrew