Page 1 of 1
Auto matic split charge relay!
Posted: 13 Nov 2006, 20:29
by DiscoDave
i know wbout the normal triggered from the alternator method but i have seen a voltage sensative relay that is triggered above 13v for split charging! anyone got any info???
Posted: 13 Nov 2006, 22:10
by mabrick
Posted: 14 Nov 2006, 13:13
by dbroada
you're thinking about a Smartcom relay. Towsure do them...
http://www.towsure.com/product.asp?p=1828
I've heard mixed reports about their quality, but not for a couple of years now - I think they are all behaving now.

Posted: 14 Nov 2006, 23:22
by DiscoDave
cheers folks, i've got one of those smart com things, not big enough in my opinion! might just have to go down the normal route!
Posted: 16 Nov 2006, 22:47
by diviy
go to your local towbar centre they charge about a tenner come on at 12.8 volts turns off when no voltage from relay
Posted: 17 Nov 2006, 07:18
by Dan Wood
Dave,
It shouldn't be too hard to knock up something using a normal relay and some reverse biased zener diodes. Probably need a transistor or two as well, depending on the coil resistance of automotive relays...
I've gotta go to werk now, but let me know if you want more info.
Posted: 17 Nov 2006, 07:37
by matt
geek alert geek alert geek alert
Posted: 17 Nov 2006, 07:54
by Mocki
dave, dont waste your time, (nor Dans) do it properly, those automatic things fail sooo oftern, and if you have other big draws on power ( Fridge, Transmitter radio, real mans driving lamps ect) it wont trigger or will drop out........... been there, done that, threw it away.....
Posted: 17 Nov 2006, 20:47
by Ian Hulley
Nah then, I believe tha's already seen the 'subtle' T'ulley Durite industrial split charge system. NOT designed by me,I hasten to add, but by a lorry,dumper,loading shovel and boat electrician. Not saying it's fool-proof but it works for us, even with the fridge working off the 85a L.battery while driving (I know it's not as per the book but .....)
Ian.
Posted: 17 Nov 2006, 21:06
by Sven
So whats the answer then chaps!!!
Posted: 22 Nov 2006, 02:28
by Vanagonman
Get this.
http://www.busdepot.com/details.jsp?partnumber=1738
Cheap to order. Will ship to the UK, and I use it and works extremely well.
Best $25 dollars (appx. 13 quid) I ever spent and a doddle to install!

That's not a voltage sensing one
Posted: 22 Nov 2006, 19:22
by cumbriankeith
Sorry to risk quelling your well-intentioned helpfulness, vanagonman....
but that one from busdepot is just a basic battery-isolating relay setup rather than a fancier voltage-sensing one that Dave is seeking - no need to import from US as they are widely available in caravan shops everywhere for a few pounds - or JK for usually a
few quid more!
There is a fancy gizmo for the job on fleabay at the moment:

It's a:
2 WAY 70 AMP DIODE BATTERY SPLITTER BY PROFESSIONAL MARINER OF CALIFORNIA USA
New spec @
this website
Re: That's not a voltage sensing one
Posted: 22 Nov 2006, 21:39
by Vanagonman
cumbriankeith wrote:Sorry to risk quelling your well-intentioned helpfulness, vanagonman....
but that one from busdepot is just a basic battery-isolating relay setup rather than a fancier voltage-sensing one that Dave is seeking - no need to import from US as they are widely available in caravan shops everywhere for a few pounds - or JK for usually a
few quid more!
There is a fancy gizmo for the job on fleabay at the moment:

It's a:
2 WAY 70 AMP DIODE BATTERY SPLITTER BY PROFESSIONAL MARINER OF CALIFORNIA USA
New spec @
this website
That's an
isolator. They require fiddling about removing the voltage regulator out of the alternator and all sorts (like very thick wires running through your vehicle, etc). The one they sell in the RV store next to my house actually comes with instructions for the Vanagon. But why bother? (unless you need the extra power for high drain)
The one I bought from the Bus Depot is simple, does the business, and is cheap as chips.
Where are you?
Posted: 22 Nov 2006, 21:55
by cumbriankeith
Ok, I take your point, v.man - maybe Dave wants much power to listen to his music or something.
Where do you hail from anyway - I take it from your moniker and your using Busdepot that you are far away from most of us - but your profile is not at all revealing - give us a clue, I'm just curious cos I've travelled quite a bit in the States...
Posted: 25 Nov 2006, 15:00
by DiscoDave
i was just after a quick simple way to run a split charge, was just an idea, but what mocki has said has forced me in to the traditional method! hey ho, more wireing to do! thanks for all your help!