Intelligent split charging relay

[cavey]

Anyone used one of these?

http://www.samlex.com/site/products/pro ... 100%20DUAL

I have a bog standard relay at the mo, and fancy fitting a voltage sensing one. This seems to be very clever and works both ways...

[g8dhe]

Should be fine and the price is good at £35 (42 Euro).

[Dodgey]

Personally I would not change it if I were you. A standard alternator activated relay has no electronics to go wrong, and if the relay fails, it's a super simple job to replace.

VSRs exist because they bypass the need to find the correct wires to tap into from the alternator - ie. they are super simple to install. You already have the hard work done, so undoing it doesn't make a whole lot of sense.

They both do the same thing;

Start your engine and your existing one connects the two batteries. Stop the engine and they are disconnected.

The VSR will do exactly the same. Your starter battery will jump to the trigger voltage in seconds when you start the engine and then link the batteries, and it will drop below 13.8 volts a few minutes after stopping the engine.

VSRs don't do anything better - they just make installation a whole lot easier.

The two way element is curious. The only application I can think of is if you have a dicky starter battery and you want it to charge when you are charging your leisure battery when on hookup / with solar. Most of the time you want the LB to take all the charge just for itself, to get the max out of your charging. If your SB is dicky you'd connect your charger to the SB instead, and then the VSR will trigger and also charge the LB when the SB is full. But charging a battery will take it over 13.8v well before it is really full, so you'll end up charging both batteries all the time....

[cavey]

Thanks Dodgey, I'd never looked at it from that perspective before. My mantra is K.I.S.S. so I think I'll stick with what I've got after your explanation! Cheers, Dave.

[Dodgey]

You are more than welcome

[Bongoed]

Very interesting reply. I have a Durite "intelligent" split charger, which has been described as 2 way. It occasionally behaves oddly, for instance it sometime clonks away in the early morning's bright sun, presumably something to do with the 180 watt solar panel. It eventually settles down. I have put a switch onto the solar panel so that I can use the solar panel on-site, and switch it out when driving.This is partly so that I can tell which device is working at any one time.It seems to happen mostly when the solar panel is switched in. Durite and the supplier seem to be at odds on this, Durite themselves say that it should be OK without the switch, the supplier advises a switch.

I realise that the clonking noise is the split charger working, but it can do it continually for a good while, which doesn't seem right to me. It is wired correctly, by the way.

The solar panel provides such a good supply in the spring and summer, I am wondering whether I need the split charger at all, but presumably in the winter it will be useful.

So the questions are, is the Durite 2-way? Does the clonking with bright morning sun show it is working correctly or incorrectly? What are the implications of using the Durite with the solar panel switched in or out? And how can I tell which unit is supplying the charge at any given time?

[g8dhe]

None of the versions here http://www.durite.co.uk/pdf/2014/5/05.1 ... lators.pdf
seem to indicate which side or sides of the circuit are sensed.

[Dodgey]

Only way you can really tell is to put a meter on the batteries and watch the voltages as the relay switches.

The clonking of the relay going mad is your solar charger topping off your LBattery to 14.8 odd volts, then backing off . The battery sags, the relay clicks off, the solar charger kicks back in, the relay switches back on, etc etc. This could be exasperated in cloudy weather where the charging current is negligible. With 180W you'll be getting good power in most weather though.

I never install panels with a switch. I also never use two way split charging relays.

It's always good to have a split charging system on top of solar as you are covered in bad weather etc. You'll always arrive at your camping location with a full battery, regardless.