Help needed with leisure battery wiring

[Fande t25]

Currently fitting my leisure battery the alternator wiring way. My question is which wire do I connect to on the alternator.

If anyone can help I'd be very happy



Eric

[pionte]

when I did mine I didnt need to touch the alternator end, everything was done besides the main starter battery, From memory ( and it isnt what it was ) the kit I used utilised the existing charge circuit , extra link wires from starter batt to leisure batt controlled by a solonoid , I dont think you really want your alternator trying to charge 2 batteries without some sort of control circuitry . If you dont get any more intelligent replies then I will take some pics and try and describe fully the system I have. I may be able to find a link to the kit I bought online too if it helps.

Martin.

[Fande t25]

Thanks Pointe

I'm installing a relay and instructions are via alternator. I called a mate in the end who talked me through a process of elimination to figure out the connection.

Eric

[pionte]

Glad you have it sorted.

[California Dreamin]

I dont think you really want your alternator trying to charge 2 batteries without some sort of control circuitry .

Martin.

With respect: the control circuitry is the alternators regulator....the relay (solenoid as you call it) just connects the two batteries together, it doesn't regulate it just switches on or off with the engine.

The wire Fande t25 is looking for on the back of the alternator is the blue exciter/ignition light circuit....don't use scotchlocs, rather re-make the spade and add the second 'switch/trigger' wire, carefully routeing it to the split charge relay.

Martin

[pionte]

The system I went for was similar to this one.... http://www.ebay.co.uk/itm/SPLIT-CHARGE- ... %26ps%3D54" onclick="window.open(this.href);return false;



Because of the location of the second ' leisure' battery , IE close to the original starter battery ( 1.9 DG so starter battery under drivers seat, leisure under passenger seat ) I didnt want to run a 60 amp cable the length of the van, my 'intelligent' relay doesnt allow charging of the leisure battery untill the starter battery is charged, this stops the alternator from trying to supply to much amperage all in one go. I only have a weedy alternator so may be different on a diesel or a westy/leisurdrive conversion.

I had read about issues with 27 + year old original wiring getting very hot when 2 batteries being charged simultaneously with no ' intelligent ' relay being used.

Martin

[California Dreamin]

The system I went for was similar to this one.... http://www.ebay.co.uk/itm/SPLIT-CHARGE- ... %26ps%3D54" onclick="window.open(this.href);return false;



Because of the location of the second ' leisure' battery , IE close to the original starter battery ( 1.9 DG so starter battery under drivers seat, leisure under passenger seat ) I didnt want to run a 60 amp cable the length of the van, my 'intelligent' relay doesnt allow charging of the leisure battery untill the starter battery is charged, this stops the alternator from trying to supply to much amperage all in one go. I only have a weedy alternator so may be different on a diesel or a westy/leisurdrive conversion.

I had read about issues with 27 + year old original wiring getting very hot when 2 batteries being charged simultaneously with no ' intelligent ' relay being used.

Martin

With the greatest of respect it is clear that neither you or the seller clearly understand how these systems work.

1) I didnt want to run a 60 amp cable the length of the van YOU DON'T! the thin wire running from the alternators exciter/ignition light circuit to the front is just the switch for the split charge relay and carries less than 1 amp.

2) my 'intelligent' relay doesnt allow charging of the leisure battery untill the starter battery is charged YES IT DOES! The Durite SMART relay is set to 'CONNECT' both batteries when it senses 13.3 volts and as the BOSCH Alternator on your van is regulated (SET) to charge at between 13.9 - 14.2 volts, the INSTANT the engine starts up (regardless of how charged the battery is) switch voltage is exceeded and your Smart relay connects both batteries.

3) this stops the alternator from trying to supply to much amperage all in one go As said above, the alternators regulator is set at 13.9 - 14.2 volts so as soon as the engine starts the battery receives that amount of volts (check for yourself) which instantly connects both batteries being higher than the relays set 'switching voltage' of 13,3 volts.

4) I only have a weedy alternator so may be different on a diesel or a westy/leisurdrive conversion. a less powerful alternator works just the same, it's just that it can't deliver as much current to the batteries so they take longer to charge.

5) I had read about issues with 27 + year old original wiring getting very hot when 2 batteries being charged simultaneously with no ' intelligent ' relay being used. Interesting comment and YES the wiring is carrying more charging current BUT CONSIDER THIS:
With a 65amp alternator the maximum theoretical charge current is 65amps (although in reality it is nowhere near as high as that).
BUT
The same wires have to carry 'STARTER CURRENT' which for a petrol engine can be as much as 160 amps (in the depths of winter with thick oil or possibly jammed in gear) .....so in comparison, the charge current even at it's maximum doesn't come close to what the main POS wire can handle.
And....just to reiterate, intelligent or smart (relays) just means it switches at a set voltage, in no way does it infer regulation of current or charge voltage.

So who is right ME or the guy selling the stuff on ebay? ME.....and I hate saying this but I do teach motor vehicle technology in a college, the other guy just sells stuff on ebay that he clearly doesn't fully understand.....that's not to say everything he wrote was inaccurate .

Martin

[pionte]

Martin, thank you for you in depth and educated reply, as said in my first response to the O/P I was just hoping to help and someone more intelligent would hopefully respond further.

It was a long time ago that I passed my auto electrical and mechanical qualifications so I would never consider myself an authority but do feel that I have a greater grasp on how things work than someone with no or little experience, hence why I will always TRY and give advice where I can.

I still dont agree with your comments on the alternator wiring having to carry the starter current of upto 160 AMPs, surely the the charging circuit and starter circuit is completely separate?

This is how I see it

battery connected to starter motor , via great big heavy duty cable capable of very High Amperage , switched by a solenoid, alternator charges battery via thin cable with max load rating not exceeding 50 AMPS ( i HAVE A 45 AMP alternator) The alternator will supply load as demanded by the battery , now I fit a shiny new leisure battery, I turn on my fridge, stereo, lights water pump, headlights etc etc the alternator tries to supply enough current to keep both batteries charged, I still think that having the system I fitted will be a better bet than just connecting additional batteries and hoping the alternator doesnt overload my vans wiring .

I am finding this thread really interesting, I am NOT suggesting that I am 100% correct and you are wrong, the way I see it is I am always looking to learn.

Martin

[California Dreamin]

Quote:
I still think that having the system I fitted will be a better bet than just connecting additional batteries and hoping the alternator does'nt overload my vans wiring .

So your alternator is now charging two batteries with the engine running, YES? and what wiring is it using to do this? the connecting wire between the two batteries, YES?
But where is the charge coming from to charge the starter battery? the alternator wiring to the starter battery YES? have you changed that wiring? NO? so you are using the original wiring to charge both batteries, YES!
The traditional type of split charge relay does exactly the same as a smart relay, there is no difference at all apart from how the relay is triggered.


Point is, add 5 batteries and the alternator can only ever charge at a max output of the alternator (in your case 45 amps) because that's what it is rated at.
Yes, charging higher perhaps for longer periods but you haven't uprated your alternator so there is always a ceiling on what can be delivered.
It is also worth noting that the alternators regulator sees the two batteries as one and takes a collective voltage reading and charges (based on PD, potential difference) between charge voltage (13.9 - 14,2) compared to collective battery voltage (that is why there are often long term issues charging two different capacity batteries in this way (but then that is another story).

Martin

Martin

[kevtherev]

I charge two leisures in parallel with a circuit taken from the wiki
(Thanks Martin)
With a 45 amp alternator, and a simple relay (not solenoid??)
I have two 60 amp wires from the alternator to the batt boxes, to offset voltage loss over the distance

After a weekend of hookless winter camping, the amperage draw from the alt has never gone over 30 amps upon initial engine start...according to the ammeter across the alt output.. for both batteries.
A faulty battery would draw a lot more, I imagine.
Intelligent chargers are pointless unless you have the power and the need to recharge quickly

Ever heard of traction batteries

Solar power is the future, it's cost has plummeted to allow it to be considered over the prehistoric and fuel sapping alternator method

[pionte]

Nope never had any dealings with traction batteries, Im sorry if my 'advice' was wrong in any way.

Just to clarify as I did use the wrong word in my original post.

extra link wires from starter batt to leisure batt controlled by a solenoid


I actually meant 'intelligent relay '

later on I said that the Starter motor was operated by a solenoid , I still believe this to be the case, it is piggy backed on the starter motor, triggered by a 12v feed from the ignition switch.

with these vehicles as in most things in life, there are usually more than one way to achieve the same goal, I chose the kit similar to the one I linked to on Ebay, for me it did what I needed it too.

I dont believe that it was wrong/better just different.


I do agree with you Kev that solar is the future.... unfortunately my drive is directly under the flight path of flocks of incontinent birds that seem to eat a diet akin to cattle.... I fear that solar panels would become covered within a few days...

[kevtherev]

Traction batteries are highly engineered batteries designed for huge amounts of amperage delivered over extended periods of time
They power fork lift trucks, golf carts etc
Trojan batteries lead the field in this technology.
for example two 6v trojan batteries wired in series offer almost 380 amp/hr.
the batteries are no bigger than a 110 amp hour "leisure or marine" battery.

so you can forget charging it up with the alternator, one charge up ...and you'll be powered up for a week.

[California Dreamin]

Pionte....your opinions are valued on here, please don't be put off in any way by my replies, it's just healthy debate which leads to a consensus on a problem.

Kindest regards
Martin

[pionte]

none taken ! im always up for debate and different ideas.

[Fande t25]

Hi all,

I've been reading this debate with interest. Much of it has been way above my head but I've been learning so thank you.

It has raised a question though. My relay kit was supplied with 6mm cable which I'm running from under the seat to the main battery. Should I upgrade the wiring whilst all the interior is out ( it's going back in next weekend). If so what wire should I use ?

Eric