On the subject of split chargers

[Chris]

Ok maybe a bit of a daft one this, but nothing new there. I have a new split charge as I battered the old one. Four wires. Two to the main battery, one to the terminal on the solenoid and the last one goes to the spare battery. So I have three wires to connect all within inches of each other and one blooming miles away in the boot. So the question is, is it essential that the wire is connected DIRECTLY to the lead terminal on the battery? This wire senses the voltage of the spare battery, but as I have mine wired with 50 mm cable and I measured the drop along it's length as effectively zero (two dec places on my meter) can I just connect the wire to the dead side of the solenoid under the bonnet?

When the solenoid closes, effectively the cable will be at whatever the voltage of the two batteries connected together is - yes? So, the readout will say what the battery is getting. When it disconnects, it will then show what the standing voltage of the spare. Difference is that I can connect the whole thing up in minutes if I don't have to mess about. If I run the sensing cable all the way to the battery terminal, I shall probably get more loss down that thin wire than I would on the big cable! I only need to know what the voltage in the battery is, when it isn't charging, don't I? When charging the voltage will always be somewhere between 12 and 14.4v.

I have jerry rigged it this lunchtime and it all seems to fire perfectly.

Eh?

Chris

 

[Jon Wildsmith]

I would / have connected it at the solenoid the way you're thinking Chris. With the wires you have there's no real difference unless you have massive current draw down that cable and even then it won't be a very big drop.

 

[Chris]

That'll do for me Jon. Could this be the shortest thread in history. Quick let's get it locked

Heigh Ho Heigh Ho it's off the Garage I go...

Chris