What battery for AUX

[KraftyPg]

Where's the Website Krafty?

Awe crap now I have to make the damn thing to ensure the facts remain true.

 

[KraftyPg]

ok well this is quite a large thread on aux batteries.

And we are still waiting for FB to make his work

so here i go. im still truggling ot find a spot for my redarc isolator under my already completely packed bonnet.

Does it have to be redarc? There are other alternatives and they are usually all different sizes which make make a difference to your mounting
point.

do i keep the 2 cranking batteries OR remove one of the batteries and install a AGM battery in the tub and integrate it into my draw system with a switch panel and fuse box to run easy wiring off for lights etc?

Personally (and note this is personal opinion I'm not saying it's fact...yet) providing the main battery is sufficient for the cranking I'd remove the second one and put one in the tub where it's of more use.

so do i keep 2 batteries and add another to the tub(AGM)? OR
remove 1 battery and add 1 to tub(AGM)

As above if 1 is adequate I'd remove 2, as to whether you want AGM that's your choice, I'd hate to give the wrong advice and suggest you don't get an AGM when you need it

is it true thhat having 2 different batteries wont work properly when it comes to charging with just a redarc isolator in place? does this have to run 2 identical batteries for it to work properly?

My two aren't the same and both charge fine, but also neither of mine are AGM, ones a 9 volt Duracell and the other is 6 AA's soldered together.

 

[FatBoy89]

And we are still waiting for FB to make his work

Does it have to be redarc? There are other alternatives and they are usually all different sizes which make make a difference to your mounting
point.

Personally (and note this is personal opinion I'm not saying it's fact...yet) providing the main battery is sufficient for the cranking I'd remove the second one and put one in the tub where it's of more use.

As above if 1 is adequate I'd remove 2, as to whether you want AGM that's your choice, I'd hate to give the wrong advice and suggest you don't get an AGM when you need it

My two aren't the same and both charge fine, but also neither of mine are AGM, ones a 9 volt Duracell and the other is 6 AA's soldered together.

I'm too lazy now. Work and finding any good excuse to go away is easier than working on thr Nav.
Down to vincentia this weekend to water ski . And bit of wheeling (not that Krafty would undertand the fun of offroad)

Krafty.... Solder? You should know better! Aa's have the ability to produce mass amounts of heat in turn causing that solder to melt and possibly cause you nav to catch fire and explode! Yes I said it! Explode! While doing 96kph on the freeway! Thought you'd know better!!
Use chicken wire!

 

[KraftyPg]

IAnd bit of wheeling (not that Krafty would undertand the fun of offroad)

And you city folk take yours on dirt once every few weekends and think you can 4wd with the best of them

Krafty.... Solder? You should know better! Aa's have the ability to produce mass amounts of heat in turn causing that solder to melt and possibly cause you nav to catch fire and explode! Yes I said it! Explode! While doing 96kph on the freeway! Thought you'd know better!!
Use chicken wire!

I have eliminated the heating issue by running 4 x 240 volts fans, it's productive because I can run multiple inverters to power the fans and then use the wind power to generate power for the charger to charge the aux battery and keep it in tip top shape.

 

[FatBoy89]

And you city folk take yours on dirt once every few weekends and think you can 4wd with the best of them

I have eliminated the heating issue by running 4 x 240 volts fans, it's productive because I can run multiple inverters to power the fans and then use the wind power to generate power for the charger to charge the aux battery and keep it in tip top shape.

It's true. I'm a Wog, but I'm a Bush fella at heart. I've considered moving out west a few times to be honest. Work loads out there aren't permitting for comfortable living for myself an the girl just yet.

I see that you have used multiple separate inverters to negate shorting between the fans and I applaud your fore thought!

Back on topic. What type of aux battery is being charger via the wind speed charge you are using? And is it capable of supplying that 15volts to "fully" charge that battery to 100% could Krafty's design of windspeed charging solve our problems of low charge?
Just the issue of having space after the fitout. Dual canopy setup with maybe B double trailer setup? All for good charge. Because lets face it. If you haven't charge that battery correctly to 100% shits just not gunna work!
You got it down pat sir!
Hop Roo

 

[KraftyPg]

Come down here, great country place and a Nissan dealership where you will be the smartest person in the place (although that may not be a compliment because dog shit is smarter than the guys at this dealership)

The aux battery is the 6 AA's, I do pump 15 volts into them but never for longer than 3 hours at a time because as you rightly pointed out they get hot.

Dual canopy....hmm I hadn't thought of that, it would be a way to make a bit more room. But seriously B double Nav, now you are just being silly

 

[FatBoy89]

Here exactly are? I
Might swell run the joint down there. I've proven to be amazing a handling dog shit. My backyard spotless!!
Scared of reversing a B-Double Krafty?
Man up princess.
D22 Road trains will be the next big thing!

 

[KraftyPg]

Never shied away from three trailers it's unlikely two would ever be an issue.

As if a D22 could pull hard enough to be a road train, only their owners pull that hard

 

[FatBoy89]

Never shied away from three trailers it's unlikely two would ever be an issue.

As if a D22 could pull hard enough to be a road train, only their owners pull that hard

I guess we are lucky enough that we can ride the clutch a couple times and not need a new one.
But what would I know.
What we lack in power. We gain in reliabilty.
But for the life of me I can't choose what's more important.

 

[KraftyPg]

I only need a new clutch when the current one doesn't match the dress I'm wearing but I've never worn one out.

You gain in reliability? So it's true, D22 drivers can get too 99 and change hands?

 

[FatBoy89]

Now your playing games. We all know 99 is not a real number!

 

[Old.Tony]

i run 2 differnt batteries off my red arc and no dramas at all. with your setup id just put an isolator between the 2 batteries and run a supply cable down to the rear for outlets or whatever you need, thats what iv seen done a couple of late model d22's

This is probably the easiest and most cost-effective method to put power in the tub.

1) Use LARGE cables to the tub to avoid voltage drop. You should be using large cables anyway, even if you were trying to charge a second/third battery in the tub, so there's no difference here.

2) Use a fuse at the start of this large cable to protect the car and battery. You'd also do this regardless of setup.

3) Make a small junction box in the tub with switches, outlets etc instead of a huge one that contains a battery.

Eventually though your second battery will die (they all do, SLI batteries last 2-5 years depending on use). Using it as a deep cycle (longer discharge times) will kill the SLI battery quicker.

Once this happens you have the option of replacing that SLI with an identical battery that will have a similar lifespan, or using an AGM battery which will cost 3x the money and last 2x the time and provide you with 2x the capacity.

The AGM will not enjoy the under-bonnet temperatures so the move to AGM will probably be accompanied by a move to the tub - utilise the same wiring, just increase the size of the box down the back.

At the same time you SHOULD move from an isolator-only to a charging unit like the C-Tek D250S which will provide the AGM with a 100% charge.

The difference in capacity? Let's assume both the SLI battery and AGM are 100Ah batteries for ease of calculation.

Under the bonnet the best charge you're likely to get on the SLI is 75% of its actual capacity, so your STARTING point is "75Ah remaining". SLI batteries should never be discharged below 50% (doing so causes dramatic sulphation rates and plate warpage) so your battery's usable capacity is 25% or 25Ah.

The AGM (charged by a D250S, or an inverter-supplied MXS-7, for example) has a STARTING point of "100Ah remaining" because these charges can and will fully charge them. An AGM (particularly the spiral wound ones) can be discharged to 20% of their capacity, so your AGM's usable capacity is 80Ah.

Quite a staggering difference but the means of achieving the difference costs money - AGMs are much more expensive and the chargers are not cheap either.

You have the option of doing this in stages which is good news!

 

[Rich64]

This is probably the easiest and most cost-effective method to put power in the tub.

1) Use LARGE cables to the tub to avoid voltage drop. You should be using large cables anyway, even if you were trying to charge a second/third battery in the tub, so there's no difference here.

2) Use a fuse at the start of this large cable to protect the car and battery. You'd also do this regardless of setup.

3) Make a small junction box in the tub with switches, outlets etc instead of a huge one that contains a battery.

Eventually though your second battery will die (they all do, SLI batteries last 2-5 years depending on use). Using it as a deep cycle (longer discharge times) will kill the SLI battery quicker.

Once this happens you have the option of replacing that SLI with an identical battery that will have a similar lifespan, or using an AGM battery which will cost 3x the money and last 2x the time and provide you with 2x the capacity.

The AGM will not enjoy the under-bonnet temperatures so the move to AGM will probably be accompanied by a move to the tub - utilise the same wiring, just increase the size of the box down the back.

At the same time you SHOULD move from an isolator-only to a charging unit like the C-Tek D250S which will provide the AGM with a 100% charge.

The difference in capacity? Let's assume both the SLI battery and AGM are 100Ah batteries for ease of calculation.

Under the bonnet the best charge you're likely to get on the SLI is 75% of its actual capacity, so your STARTING point is "75Ah remaining". SLI batteries should never be discharged below 50% (doing so causes dramatic sulphation rates and plate warpage) so your battery's usable capacity is 25% or 25Ah.

The AGM (charged by a D250S, or an inverter-supplied MXS-7, for example) has a STARTING point of "100Ah remaining" because these charges can and will fully charge them. An AGM (particularly the spiral wound ones) can be discharged to 20% of their capacity, so your AGM's usable capacity is 80Ah.

Quite a staggering difference but the means of achieving the difference costs money - AGMs are much more expensive and the chargers are not cheap either.

You have the option of doing this in stages which is good news!

All sound advice Tony and based on sound principals, however I fear you have wasted your time, as it seems people just don't want to listen.

 

[BravoBrad]

2) Use a fuse at the start of this large cable to protect the car and battery. You'd also do this regardless of setup.

Fuse both ends of the cable (ie at the starter battery and at the Aux Battery)

 

[FatBoy89]

All sound advice Tony and based on sound principals, however I fear you have wasted your time, as it seems people just don't want to listen.

That's harsh, I listen, take it on board and then discard it and go with what I originally was going to do

 

[Old.Tony]

All sound advice Tony and based on sound principals, however I fear you have wasted your time, as it seems people just don't want to listen.

There are two problems here.

First, I'm not a shareholder in a battery or a charger company, I'm just a guy that reads a shitload of stuff and tries to coherently regurgitate it where it might help, so without an agenda I'm probably pushing the wrong barrow around.

Second, in trying to save money in the first instance, people are going to take shortcuts and make choices that, once they have made the choice and completed the purchase they will be disappointed and then "try the next level up". For some of us, we've already done that, spent the money, frowned at the poor performance and spent MORE money improving it, usually to end up where we're saying "this is how we'd do it".

Those of us that are just trying things out for the first time are the ones asking the questions and a lot of the responses vary. However, there are limits to these things - there's no better battery than an AGM, for instance, but in order to GET the better battery and KEEP it you need to spend the money up front and use it sensibly (for example, not have it in your engine bay and don't discharge too far).

Whether anyone bothers to listen, read, learn or just assume any thread is "a nice coincidental arrangement of alphabet soup, shuddup and bring on dessert" is completely their business. If they bother to ask a question that's half the miles travelled - some go right ahead blindly stabbing in the dark. Some don't have the confidence to ask the question at all, preferring to sit on the sidelines and see if their question is answered. Some ask and don't get an answer that matches with their expectations so they ignore everything (which is not always a bad thing) and some ask, get an answer and act on it.

Often when I'm explaining something I'll do it for the base level - I might know that someone is aware what a certain item is, but for the sake of other readers I might explain a certain point a little more clearly. It makes posts larger, but hopefully more complete - so that the guys who don't ask but still read can get some value out of it.

Whether we get what we came for or not is entirely up to us. Our involvement in this forum is to be a part of the community that this forum created. We are here with a common goal. Whether any individual member wants to actually contribute, or learn from, or just be a larrikin, is up to them and as long as the majority of the people are enjoying themselves and getting something from the place, the place will thrive.

/soapbox

 

[KraftyPg]

And I'm a guy that's been doing it for 20 years or more with zero failures, done the electrical theory, studied both 240 and 12 volt theory extensively and work with people who between them have a collective total of over 150 years of experience in automotive technology and automotive electronics.

What you subscribe to is your own choice but people should do themselves a favour and not just rely on internet theory and call it fact. Fine people want to charge their batteries 15 different ways and build in over priced redundancies but to claim it's the best and or only way things should be done is stupid, there is always more than one way to do things.

There is several major flaws in alternators not being good enough to charge a battery to 100%, there is several flaws in electrical theory claiming 6mm cable is adequate but if people aren't smart enough to see those flaws then fine but be happy to accept the fact that some people in this world are smart enough.

 

[terryc]

There is several major flaws in alternators not being good enough to charge a battery to 100%,

"Please explain"

and I think "There are several" is proper grammar.

<now wtf is the mistake I've made >

 

[Old.Tony]

Krafty's right in that most alternators WILL charge a battery to 100%. It's just that they'll never do it under normal - or even extended use - conditions. It's designed NOT to. Fully charging a lead-acid battery in a reasonable time period requires around 15V applied to the battery and the maximum output of a car alternator should be 14.7V.

It WILL charge the battery to full, but it will take a VERY long time to do it, much longer than most car engines are left running.

Not to mention that the D40's alternator actually shuts down as the battery reaches its nominal 70-75% charge level anyway, making it nearly impossible to fully charge the SLI battery. It's yet another reason to employ either a good DC-DC charger like the D250S or an inverter-powered house charger for any aux battery.

I'm going to graph my battery voltage on my next long trip and see what the result is, just so I can be certain what's going on. My 2009 D40 may NOT shut down its alternator - looks like the 2010 model does, perhaps to conserve engine power (and fuel economy) as well as extend the battery/alternator life?

 

[terryc]

Tony

You have basically posted what I understand happens with car alternators