Correct wiring and battery set up advice needed

[Bloodyaussie]

I need some advice as to best set up my batteries and what option would be best with what I have already here.

I currently have 3 batteries in my car and this is from when the car was petrol and could only fit a small battery as the aux but now I have a 105a under the bonnet but still have an 85a in the back.

I have a 90amp alternator (new) and a basic isolator (my redarc died).

The 105 and 85 are joined together on one side and then of course the cranking battery, Matty said I should join the 2 big batteries together permanently and have the 85a in the back as the aux with a DC to DC charger but I do not have the money to buy one at this point in time.

I have fridge, oven, and rear light plus lots of smaller stuff running from the 2 aux batteries.

A couple of people have told me to lose the third battery now I have a diesel?

I have a 40watt solar panel plus another 180w I will only use when camping for extended periods.

There are a few different ways to go but I struggle with electrics so would love some advice.

Cheers

[AB]

I would loose the third battery in the rear.


From my limited knowledge joining both batteries would mean your 105 battery will not fully charge.

Still take the 85 on camping with your solar panel if you want too. I take a spare 65 and my panel so Leah has power in the camper if we go off driving.

[macca]

I have been fiddling with this for many years, tried all sorts of systems and ended up with a system that works as we all want ours to.
BUT it is pricey, if I hadn't wasted so much on other systems the cost overall would be way less DOH
Simply if your keeping what you have do it right.
Cuppa and evil-twin both have good advice, and really know the solar side as well, I will defer to them.

http://www.nissanpatrol.com.au/forums/showthread.php?31290-Redarc-BCDC1240-Install&p=566836#post566836 post #23

[lucus30]

I would loose the third battery in the rear.


From my limited knowledge joining both batteries would mean your 105 battery will not fully charge.

Still take the 85 on camping with your solar panel if you want too. I take a spare 65 and my panel so Leah has power in the camper if we go off driving.

Chuck the 3rd battery in a battery box if it isn't already and only take it camping. Charge it at home on a trickle charge before you go and top it up with the solar while out.

If you hook the two batteries up assuming they are the same chemistry both should fully charge but I'd make sure they were fully charged before connecting them

[Bloodyaussie]

I already have another 105a as a spare given to me by a mate but thought had died during the engine conversion period but Matfew took it and gave it some love and it is alive.. I use it in a Ark battery pack.

I just found my glasses after weeks of searching so it makes it much easier to read through all of Cuppa's doctrines ...lol.

At the moment none of it is too useful as I cannot afford a dc to dc charger and most of it from what I have read so far is based around that sort of set up... I dont want to kill anymore batteries.

[Punderhead]

Don't know exactly what your chasing but here is an idea.

Dad has a 4.8 gu, with the abs pack and also LPG. With the both of those there was no room for a second battery under bonnet. As such, he set up his battery isolator etc under bonnet, and ran the wires to the back of the car. From there he teed off, and has placed one Anderson plug inside the back of the wagon, And an Anderson plug next to the trailer plug. When he takes the fridge somewhere, he slides the battery in box next to it, and just plugs it in. He also had a third battery in the camper, that again plugs in.

Takes a few seconds to install/remove, and not in the way at all when you don't need it.


As for the solar I have nothing

Cheers.

[Bigcol]

you could have a look at this
on a caravan forum I am on, this is the set up of one guy

55054

for the wiring of the car & Van

55055


may or may not help................

[threedogs]

When I spoke to Alan Johnson from Piranha about running a third battery
he said if I had a 100amp alternator it would be fine
Dont know how you would go with a 90 amp alternator

I ran three batteries without a problem in my other 4x4,with a 100 amp alternator

[BigRAWesty]

So I'm assuming the one in cab is not lead acid?

If that's correct then it's a dc-dc to get the best out of it or remove it as you'll just kill it being inline with your cranking battery..

I'd just run the 2 under bonnet with the simple voltage activated solenoid.. Given they are the same chemistry aswell

[Bloodyaussie]

So I'm assuming the one in cab is not lead acid?

If that's correct then it's a dc-dc to get the best out of it or remove it as you'll just kill it being inline with your cranking battery..

I'd just run the 2 under bonnet with the simple voltage activated solenoid.. Given they are the same chemistry aswell

No it is not but it is vented... I forgot I also have a big sine wave inverter.

[the evil twin]

I have made a few guesses about your setup in coming up with the following suggestions
The main factors you mention for sure are-
That you have an Oven and Sine Wave Inverter (both use high current when they are running)
That a DC-DC charger is not in the budget at the moment.
A 90 amp Alternator is used (not much advantage in a bigger one anyway really)
You have 180 watts of Solar for camping that must have some sort of Reg already
Not sure what you have for the 40

Sooo,
I would do the following
-keep the basic Isolator under the bonnet
-in the existing leads that supply the rear (3rd) battery disconnect the battery and fit an Anderson Power Pole or mini Anderson or similar plug.
-remove the rear battery and for whenever you need it make a small fly lead for it that plugs into the Anderson.
-keep the existing power distribution to accessories in the rear however you have it set up so it runs on the under bonnet aux if the 3rd battery isn't fitted.
So far you have spent about $10
- not sure what you have with the 40 or what you intend but if it is going on the vehicle permanent then a cheaper PV reg will be all you need for floating the batteries
Maybe $30 so that is $40
- keep the 3rd battery charged up at home on a decent mains or solar charger (use the 40 panel and reg if it isn't on the truck) every week or so
- regularly (once a monthish) and after any major use of the Aux put a mains charger on the vehicle for 24 hours or so
- if it is feasible and you can use one reg and swap it between the 40 and the 180 panels then even better.

Remember, a Solar Panel and Reg is a DC/DC charger so use it whenever it is available

Advantages to you
Cost
Simplicity
Versatility
The aux's will charge quicker to 80%-85% off the Alternator than a DC/DC if they are well down on charge

Disadvantages to you
You need to remember to isolate the Cranker and reconnect the Aux/s
You may lose a small amount of battery capacity (maybe 10% max) in some circumstances of low solar availability and higher power useage

Hope that helps

[BigRAWesty]

I have made a few guesses about your setup in coming up with the following suggestions The main factors you mention for sure are- That you have an Oven and Sine Wave Inverter (both use high current when they are running) That a DC-DC charger is not in the budget at the moment. A 90 amp Alternator is used (not much advantage in a bigger one anyway really) You have 180 watts of Solar for camping that must have some sort of Reg already Not sure what you have for the 40 Sooo, I would do the following -keep the basic Isolator under the bonnet -in the existing leads that supply the rear (3rd) battery disconnect the battery and fit an Anderson Power Pole or mini Anderson or similar plug. -remove the rear battery and for whenever you need it make a small fly lead for it that plugs into the Anderson. -keep the existing power distribution to accessories in the rear however you have it set up so it runs on the under bonnet aux if the 3rd battery isn't fitted. So far you have spent about $10 - not sure what you have with the 40 or what you intend but if it is going on the vehicle permanent then a cheaper PV reg will be all you need for floating the batteries Maybe $30 so that is $40 - keep the 3rd battery charged up at home on a decent mains or solar charger (use the 40 panel and reg if it isn't on the truck) every week or so - regularly (once a monthish) and after any major use of the Aux put a mains charger on the vehicle for 24 hours or so - if it is feasible and you can use one reg and swap it between the 40 and the 180 panels then even better. Remember, a Solar Panel and Reg is a DC/DC charger so use it whenever it is available Advantages to you Cost Simplicity Versatility The aux's will charge quicker to 80%-85% off the Alternator than a DC/DC if they are well down on charge Disadvantages to you You need to remember to isolate the Cranker and reconnect the Aux/s You may lose a small amount of battery capacity (maybe 10% max) in some circumstances of low solar availability and higher power useage Hope that helps
What about the mixing of chemistry between 2nd and 3rd batteries??

[Cuppa]

What follows is for your consideration, as usual it just my flow of thoughts so may or may not be as coherent as I’d like. :)

Macca is correct when he suggests ya gotta spend some money to get an ideal/efficient system where you know it will ‘just work’.

That said you do have a system you can use even if it is less than ideal & is inefficient. If I’ve understood correctly you have a collection of batteries of unknown condition & remaining capacity by virtue of their past life, but sounding likely that they have been abused & are not in the greatest condition. If that is so, then the aim is just to keep them going until you can afford new batteries. Luckily what they need to keep them going as long as possible is the same as what a new set of batteries will need to ensure a long life.

One thing I will emphasise - DO NOT BELIEVE ANYONE who tells you you can ‘flatten’ any battery, deep cycle or not, & then recharge it...... at least not if you want your batteries to last. Letting your batteries get down to the point where the fridge cuts out or the inverter low voltage alarm sounds is seriously bad for your batteries health. I repeat do not believe anyone who says different, regardless of whether they are a fridge manufacturer or the bloke who claims his batteries are just fine doing so (ask him in 12 to 18 months time why he’s bought new batteries). Discharging batteries to 40% to 50% is the go. That means not below 12.1v or 12.0V at the lowest!

There is nothing wrong with having the third battery in the back as you have ...BUT.... you need some seriously heavy cable between the aux under the bonnet & the aux in the back. (Consider that ‘standard’ battery cables under the bonnet ar 35mm2 - the greater the distance between batteries the heavier cable required) The idea would be to allow sufficient current flow between the under bonnet aux & the rear aux so that they effectively charge as a ’single’ battery. If the cable is not heavy enough much of the ‘charge’ to the rear will be lost in warming up the cable. Bigger is better but can get very expensive. I used 70mm2 cable in my front to rear setup not cheap ........ unless you know of a source of used heavy duty welding cable. Move the rear battery closer to the front if you can to reduce cable length. You can use the chassis for earth, but this is less reliable than direct cable.

You will have read about my thoughts on installing Dc to Dc chargers. Generally I consider them to be a good thing because of their ’multi stage’ charging capability (aka ’smart charging’). At risk of being boring by repeating myself, their advantage is they have the capability of charging batteries to 100%, alternators alone will not do so in everyday use. The point is that if you can’t charge your battery to 100% (& can only discharge it to 40% to 50% if you want it to last) this is significant. Smart charging can as much as double your ‘useable capacity’. Batteries which are only ever charged to 70% to 80% (which is what an alternator or any ‘dumb’ charger will do) will not last so long. 4 years is an average life of a starter battery - smart charged deep cycle batteries commonly see 10 years.

There are alternative ways of ’smart charging’ aux batteries other than DC to DC chargers. Whether they are cheaper depends upon what you already have or can get at reasonable cost.
1. All solar regulators will be smart chargers. ‘Bulk charging’ the batteries from the alternator & then ’topping them up’ from solar is quite a reasonable option. I wouldn’t worry overly about MPPT but I would suggest you use a regulator better than the pieces of crap that commonly get supplied on the back of panels, also the regulator should be close to the batteries & be preferably temperature compensated. These things make a difference to how much of the panel’s output gets’s squeezerd into you batteries rather than wasted. Little differences are cumulative.

2. If you have an inverter & a multi stage mains charger, you can set up your own version of a dc to dc charger. Not quite as efficient, but used widely in motorhomes before dc to dc became commonplace. Essentially you run the inverter (modified sine wave is ok & cheaper than pure sine wave) off the crank battery, plug the mains charger into the inverter & charge the aux from the mains charger. The ‘risk’ with this set up is that when driving you have a cable (between inverter & mains charger) which is live 240v. The risk is in an accident situation - if this cable were shorted to the vehicle body it could electrocute someone - possibly the SES bloke who has come to cut you out of the mangled wreck, possibly occupants of the vehicle. The generally acceted way to mitigate this risk was to place the inverter & mains charger very close together to keep the 240v cable as short as possible (& to armour it if possible). There would still be plenty of motorhomes getting around with this system.

All of your batteries will be lead acid, but among these you may have a mix of wet, AGM or Gel. Not ideal, but I had wets & AGM’s paralleled for years without problem - so I wouldn’t worry about that. Different if you have a Calcium type (also lead acid) battery though.

DO NOT smart charge a wet battery INSIDE the vehicle. When wet batteries are fully charged they will bubble & gas - inside the vehicle this stinks as well as representing an explosive risk. Using AGM or Gel batteries inside is ok.

If smart charging a wet battery it will need regularly checking & topping up with distilled water or it will dry out (a surefire method of battery killing too).

EDIT. I see ET has posted whilst I’ve been writing, so I’ll nw have a read of his stuff to see if we are or are not in agreement. LOL. There’s always more than one way to skin a cat!

[the evil twin]

What about the mixing of chemistry between 2nd and 3rd batteries??

If one of the batteries isn't full Calcium, Lithium or other exotic technology it won't matter as worth a damn

[Bloodyaussie]

I have made a few guesses about your setup in coming up with the following suggestions
The main factors you mention for sure are-
That you have an Oven and Sine Wave Inverter (both use high current when they are running)
That a DC-DC charger is not in the budget at the moment.
A 90 amp Alternator is used (not much advantage in a bigger one anyway really)
You have 180 watts of Solar for camping that must have some sort of Reg already
Not sure what you have for the 40

Sooo,
I would do the following
-keep the basic Isolator under the bonnet
-in the existing leads that supply the rear (3rd) battery disconnect the battery and fit an Anderson Power Pole or mini Anderson or similar plug.
-remove the rear battery and for whenever you need it make a small fly lead for it that plugs into the Anderson.
-keep the existing power distribution to accessories in the rear however you have it set up so it runs on the under bonnet aux if the 3rd battery isn't fitted.
So far you have spent about $10
- not sure what you have with the 40 or what you intend but if it is going on the vehicle permanent then a cheaper PV reg will be all you need for floating the batteries
Maybe $30 so that is $40
- keep the 3rd battery charged up at home on a decent mains or solar charger (use the 40 panel and reg if it isn't on the truck) every week or so
- regularly (once a monthish) and after any major use of the Aux put a mains charger on the vehicle for 24 hours or so
- if it is feasible and you can use one reg and swap it between the 40 and the 180 panels then even better.

Remember, a Solar Panel and Reg is a DC/DC charger so use it whenever it is available

Advantages to you
Cost
Simplicity
Versatility
The aux's will charge quicker to 80%-85% off the Alternator than a DC/DC if they are well down on charge

Disadvantages to you
You need to remember to isolate the Cranker and reconnect the Aux/s
You may lose a small amount of battery capacity (maybe 10% max) in some circumstances of low solar availability and higher power useage

Hope that helps

Ok this is what I have done for now.... all your assumptions are correct and I have basically done everything you mentioned.

I already had an anderson plug set up so only made minor changes there.. the 40w has a reg and I am using the 40w on the cranking battery and the 180w on the aux right now charging the car.

I already had the larger gauge wire running through the car as I was warned about voltage drop over a long distance.

The power from the aux is going into a junction that is feeding the accessories at the back plus the inverter and I have redone the earth as I had my doubts.

I cannot see me spending the money on a redarc and will probably buy one of those Ctek jobs when I can afford it but for now I think this set up will get me through as I think I may need a good battery charger at home or will the panels do for now?

I had the intention of running the 40w on the roof but for the sake of safety of my cars it is now parked where the roof rack must come off and is only put on when really needed.

Thanks so much for the help so far I really appreciate it.

[threedogs]

why not use your panels free power .
I have a 20watt panel the does my lighting and radio in the back yard,
Then I make sure that battery pack is full and take it away for camp lights.
Never ran out of 12v power yet at camp
I take it you only use the Travel Buddy on the move they
draw a hell of a lot a power to be used stationary

[the evil twin]

Ok this is what I have done for now.... all your assumptions are correct and I have basically done everything you mentioned.

I already had an anderson plug set up so only made minor changes there.. the 40w has a reg and I am using the 40w on the cranking battery and the 180w on the aux right now charging the car.

I already had the larger gauge wire running through the car as I was warned about voltage drop over a long distance.

The power from the aux is going into a junction that is feeding the accessories at the back plus the inverter and I have redone the earth as I had my doubts.

I cannot see me spending the money on a redarc and will probably buy one of those Ctek jobs when I can afford it but for now I think this set up will get me through as I think I may need a good battery charger at home or will the panels do for now?

I had the intention of running the 40w on the roof but for the sake of safety of my cars it is now parked where the roof rack must come off and is only put on when really needed.

Thanks so much for the help so far I really appreciate it.

Awesome...

Only comments I have are;
-Unless you have recently used the Aux/s then all you need for the 'backyard' is the 40 on the cranker and use the isolator to connect the aux.
(I have 300 A/H of battery capacity in my van and it floats happily on a 50 watt panel when not in use)

-If you are set up as described why even bother with a Ctek
You have Solar with regs
You have a battery isolator that allows back feeds for starting/winching off the Aux if needed
You have heavy cable with no voltage drop

A DC/DC charger won't do much to improve that setup.
It will put all your eggs in one basket if it fails
It will mean you cannot backfeed (unless you leave the existing solenoid and wiring in there as well)
It won't charge your Aux's any quicker overall
It will ensure the best charge on the road but won't do any better than the existing Solar when stopped/camped

[Bloodyaussie]

So with the 40w panel connected to the Cranking battery the isolator will switch over and charge the aux as needed?

Also what volts should be showing while its charging the batteries?

And yes I had an issue with an isolator and the aux ran flat??? It happened last week when shooting... my beer got warm!!!

Thanks for the advice on the ctek...

[AB]

So with the 40w panel connected to the Cranking battery the isolator will switch over and charge the aux as needed?..

Yes, my piranha system switches over.

[the evil twin]

So with the 40w panel connected to the Cranking battery the isolator will switch over and charge the aux as needed?


Uuuummmm, I thought when you said your Redarc went cactus you meant an SBI12 Redarc and now had fitted an ordinary solenoid?
If that is the case all you need do is connect the panel to either battery and energise the solenoid
If you still have a smart solenoid in there it is possible the solar isn't reaching the cut in voltage so just use the override facility



Also what volts should be showing while its charging the batteries?


Depends on the reg but they should absorb charge at about 13.6 to 14.0 volts (13.8 nominal) and float at about 13.2 ish Volts and there should be minimal current flow.
When the sun isn't on the panel the battery should have about 12.6 to 12.9 volts "surface charge".




And yes I had an issue with an isolator and the aux ran flat??? It happened last week when shooting... my beer got warm!!!


Any electrical device that does that when I have a weapon in my hand is usually immediately subjected to high kinetic energy impact field testing.

[Bloodyaussie]

The other 105ah battery I have is stuffed.

I put it on load using the oven and checked the voltage and it dropped to 10v but it is 4 years old and I did not care for it properly.
The isolator is a cheap switching type and is working fine but will replace with a proper one when I can.

I checked and both batteries are charging from the 40w panel.

[the evil twin]

If you do choose to replace the Solenoid may I recommend a dual sensing one such as Intervolt or Redarc SBI12D.
What that means is no matter where a charging source is connected it will charge all batteries.
Costs a little more but handy

Yeah, that battery is now a door stop

[Bloodyaussie]

Cheers mate I was looking at those intervolt ones.. look like a good bit of kit.

There are a couple of units I am keeping my eye on and see if I can get on soon... I have been lazy and have a heap of crap I will put on ebay as faceache keeps stuffing me about dealing with dickheads so should have a little cash??

[Bob]

I have been lazy and have a heap of crap I will put on ebay as faceache keeps stuffing me about dealing with dickheads so should have a little cash??

I have also had a fair amount of success selling on Gumtree BA

[Bloodyaussie]

I have just checked the 85ah that was in the very back of my car and is now in a portable battery box and the multi meter says it is charging at 12.96v ??

The panel is the 180w and it is in full sun.

The other 40w panel is hooked to the cars cranking battery and it is sitting at 13.30v..

Any ideas?

[the evil twin]

Assuming the regs are smart enough and the bateries in question are not down on charge thru useage the most likely scenario is...

The 180 Watt 85 AH combo is charged and the reg is in the float phase.
The 40 Watt vehicle combo is in the absorption phase and the reg is loaded down to 13.3.

[Bloodyaussie]

Assuming the regs are smart enough and the bateries in question are not down on charge thru useage the most likely scenario is...

The 180 Watt 85 AH combo is charged and the reg is in the float phase.
The 40 Watt vehicle combo is in the absorption phase and the reg is loaded down to 13.3.

I will put the 85ah under load with the oven and see what it does.

I will wait until the sun goes then test it.