Triple battery setup run down.

[mudski]

So I have been searching our forum for triple battery setup's. As we get our camper in a few weeks and need to prepare the car...Read a fair bit but just want to ask to make sure I have it correct as per my current setup of what I have.
I have the cranking battery, connecting to the 105AH deep cycle aux battery via a Redarc SBI12 isolator.
Is it best to run the cable down the back of the car from the cranking battery or the auxiliary battery? I was first under the assumption its from the cranking battery, then I found a thread where it was from the auxiliary battery.
I have some 6B&S cable here I will use....

Cheers.

[MudRunnerTD]

Yeah I would think that it would come from the aux battery or split direct from the redarc. I have mine from the redarc to an Anderson plug at the rear.

My logic is that your battery management system (redarc) is designed to manage your cranking battery first as the primary battery then your aux battery or batteries once your primary is fully charged.

[BigRAWesty]

Will you be running a charger for both batteries?
If so run both of the cranking battery so the are both drawing raw voltage Off the alternator once the main cranking battery has charged.
But if you intend in running the trailer battery and aux battery off the same charger the run your cable from either the charger or the aux battery.

Any solar in the mix?
Also 6b&s?? What size mm is that?

[mudski]

Yeah I have got 180w solar panels for when we set up camp but will be selling them with the AGM I have now as firstly the panels are huge, too big to carry and second, the trailer comes with a battery fitted so I don't really need it anyhow. Pity, as I only bought it before easter and used it once...



Is your 3rd got a charger like your second? If so I'd go cracking battery.
If you go the 1st aux battvery then your 3rd has to wait for cranking to charge and then the 1st aux to charge before getting anything.
If On cracking then both aux batteries will charge at the same time.
But also your not wasting voltage. Your aux is already regulated by the first redarc, so charging 3rd will be slower again.

If not the as MR, run both from the redarc charger..

That's my theory.. Cuppa will probably disagree but he's been doing it longer than me... :p
Any solar in the mix?
Also 6b&s?? What size mm is that?
The third is the trailer battery Kallen. So now I have only two, one cranking and one aux battery. So I will have three all up in the end. Going by your first sentence it looks like you think I already have two aux batteries and are looking to instal a third???

[mudski]

Also 6b&s?? What size mm is that?
14 mm squared
stranding 168/0.32
6 gauge
125 amp rated

[MudRunnerTD]

Yeah I have got 180w solar panels for when we set up camp but will be selling them with the AGM I have now as firstly the panels are huge, too big to carry and second, the trailer comes with a battery fitted so I don't really need it anyhow. Pity, as I only bought it before easter and used it once...



Hey mudski when your ready I'd be interested in some details of your solar setup mate, might be interested.....maybe.

[BigRAWesty]

I got a bit confusing hay.
I'll change it to make it more understandable... Lol night shift...

I'd also run an isolator on the trailer line. So when it's not connected you can safely terminate the power from the rear of the car and eliminate any chance of a short..

[mudski]

Hey mudski when your ready I'd be interested in some details of your solar setup mate, might be interested.....maybe.
Its 3 80w panels that fold up, I have change the crappy reg that was on it to a Suntrans 20a reg and also change the 10m lead from the reg to the battery clips using 6 B&S cable.
I'll have to find the specs on the panels if you want more info....


I got a bit confusing hay.
I'll change it to make it more understandable... Lol night shift...

I'd also run an isolator on the trailer line. So when it's not connected you can safely terminate the power from the rear of the car and eliminate any chance of a short..
Good point there....

[Cuppa]

"That's my theory.. Cuppa will probably disagree but he's been doing it longer than me... "

Half. :)
I would connect the trailer battery to the crank battery, & because it is way back in the trailer I wouldn't use an isolator like the SBI12, instead I would use a DC to DC charger. 6B&S is good, but with length & connections there is still a possibility of resistance/voltage drop. A DC to DC charger will take care of this if mounted near the battery in the trailer. A second SBI12 would work, but not very efficiently compared to a dc to dc charger. (The SBI12 only allows for standard alternator charging which will only seethe trailer battery charged to about 70% capacity ).

The SBI12 does not regulate anything, nor is it a 'charger'. It is basically a voltage controlled on/of switch to prevent the crank battery being inadvertantly flattened. A DC to DC charger will regulate the charge boosting the voltage if necessary to ensure that optimum charging from the available source (crank battery) will occur ensuring the trailer battery is charged to 100% capacity. This also assists if their is any voltage drop from the length of cable/connectors.It also functions as a 'crank battery protector' like the SBI12. Whilst an aux battery under the bonnet, used primarily for winching with the motor running, or small loads can get by with only being charged to 70%(ish), a battery in the trailer used to run a fridge while camping, without running the vehicle really needs to be fully charged, or you will find that you either have less running time than you would like, or you will end up prematurely murdering your battery through over discharging it. Whilst a dc to dc charger costs a bit more to buy than a Voltage Sensitive Relay (VSR) like the SBI12, in the longer term it will save you money (batteries aren't cheap) as well as making camp life a bit easier. VSR's have become largely superseded these days.

Cuppa

[megatexture]

I've got mine much like you are describing only I have a crank and aux on the car and two aux on the camper, both on the trailer bum off the aux batt on the car via Anderson plug and I've never had an issue. I've also got a 120w panel for longer stays with plans to purchase a second 120w

Edit:I use a ctek 250 dual on the car

[Cuppa]

I've got mine much like you are describing only I have a crank and aux on the car and two aux on the camper, both on the trailer bum off the aux batt on the car via Anderson plug and I've never had an issue. I've also got a 120w panel for longer stays with plans to purchase a second 120w

Edit:I use a ctek 250 dual on the car

I assume you mean that the two camper batteries are connected to the aux under the bonnet via the Ctek?

[Cuppa]

There are 'many ways to skin a cat' , particuarly when setting up mobile charging systems. All work, but some work better than others. When using battery power for camping aiming for maximum efficiency makes sense as it enables longer overall battery life, & greater camp convenience. Which is chosen is best determined by usage patterns, but more often is determined by the thickness of the wallet. Life is full of compromises. Some better than others.

[megatexture]

I assume you mean that the two camper batteries are connected to the aux under the bonnet via the Ctek?

The ctek is charging the aux under the bonnet then onto the camper via Anderson

As we do trips without the camper I've put the ctek in the car not camper and connect the solar panel to the ctek if needed. When the campers in storage its maintained with a ctek mxs15 so its at max to start with and once we get to our destination the panel is out.

[BigRAWesty]

The ctek is charging the aux under the bonnet then onto the camper via Anderson

As we do trips without the camper I've put the ctek in the car not camper and connect the solar panel to the ctek if needed. When the campers in storage its maintained with a ctek mxs15 so its at max to start with and once we get to our destination the panel is out.

Just touching On what I mentioned before, have you fitted an isolator to the line going to trailer?

[megatexture]

Its used as a Power supply to the rear fuse block for the fridge and other accessories I can't put an isolator on it

[BigRAWesty]

Yea fair enough on that one.

[Cuppa]

The ctek is charging the aux under the bonnet then onto the camper via Anderson

As we do trips without the camper I've put the ctek in the car not camper and connect the solar panel to the ctek if needed. When the campers in storage its maintained with a ctek mxs15 so its at max to start with and once we get to our destination the panel is out.

Aha, so the ctek in the car 'sees' the three batteries as a single unit. How do you manage when camped but have disconnected the vehicle from the camper to go off for a drive? I would wonder if there might be occasions when you want to hook up & drive, immediately after a drive without the camper connected. In which case the aux battery would be fully charged, but the camper batteries would be depleted (from running the fridge etc whilst you had been off driving without the camper). Most times this wouldn't be an issue as given time the three batteries would balance themselves once reconnected. But what happens when you reconnect & drive away immediately? would't the ctek see the aux as charged & not in need of charging, not charging the camper batteries until the voltage in all three had dropped (balanced). This may not be an issue, but I can imagine a possibility where on occasions you stop set up camp & find the batteries are not as fully charged as you need? I suppose it depends upon how quickly the batteries balance themselves & how long you drive for & how long you intend to camp without driving again (The capacity of three batteries would likely give a reasonably sufficient 'buffer' if the next stop was only a short one & the sun was shining). Those three factors could make it a non issue for you, where for some it may be. A fine example of how 'pattern of usage' varies what will work for some & not others I suspect, & a reason to always ask what the pattern of usage is as well as 'what does the user want to run'?

Cuppa

[mudski]

O.k so I keep my SBI12 and buy a dc to dc charger and mount this in the trailer or in the rear of the car? Any recommendations on what charger?

[threedogs]

What are you running that's requires all these batteries??

[mudski]

What are you running that's requires all these batteries??
I have the standard setup in my car. Cranking and Auxilary battery. Our Camper that we have bought will have its own battery aswell. Which will run my 75L combi and a couple of strip lights. I ran my combi for fours days plus two lights on my current 110AH AGM I have, no solar charging too. Was quite impressed really.

[Cuppa]

O.k so I keep my SBI12 and buy a dc to dc charger and mount this in the trailer or in the rear of the car? Any recommendations on what charger?

What capacity trailer battery?
What is the average daily power usage (amp hours) of your fridge, plus any other power usage (lighting, music, water pump etc)
How often do you intend to drive?
Is this for weekends away, a couple of weeks away or longer?

The two name brands are Ctek & Redarc.
I have no experience of the Ctek, but others who have them are happy with their purchase.
I have a Redarc & am happy with my purchase.

Here is the Redarc range (http://www.redarc.com.au/products/category/4wd-dc-battery-chargers/) (ignore the prices, they can be bought a lot cheaper). The size which would suit you best depends upon the answers to the questions above.

A larger amperage unit will bring the charge of a depleted battery up to around 70% more quickly (less driving time) than a smaller amperage unit, but to get that all important top 30% into the battery will take the same amount of time regardless of the amperage of the charger, so choice is dependent upon how much you expect to take out of your trailer battery between (percentage of battery capacity) driving with the trailer attached.

eg. if driving (with trailer attached) all day most days it is likely that a smaller unit would do just as well as a larger one, but if stopping for a couple of nights at a time & taking more out of your battery, & then only driving (with trailer attached) for half a day a larger unit may be better.

In my case my batteries being charged by the Redarc 40 amp charger are 3 x 120Ah, possibly being taken down to 50% capacity over several days. In my case it makes sense to have a larger unit because the batteries would be able to accept the full 40 amps for 3 hours plus in such circumstances, & a reduced charge until full for the rest of the driving day. Most of the time my batteries would not be taken down to 50% (using solar) & the full capacity of the charger not used, but the set up takes into account worst case scenarios, much more important if full time on the road.

Cuppa

[Winnie]

I have the standard setup in my car. Cranking and Auxilary battery. Our Camper that we have bought will have its own battery aswell. Which will run my 75L combi and a couple of strip lights. I ran my combi for fours days plus two lights on my current 110AH AGM I have, no solar charging too. Was quite impressed really.

Hugely depends on the weather, I've only got a cranking battery in mine and in winter my 40L fridge can run for a week and I can still start the car, but in warmer season it will be flat after 3 days.

[threedogs]

Some nights like last time we went away we didn't need camp lighting , only stars and campfire.
In the desert you can nearly read a book when the moon is full,
Some say during winter to turn your fridge off and leave lid open.
Never tried it but makes a little bit of sense

[mudski]

What capacity trailer battery?
What is the average daily power usage (amp hours) of your fridge, plus any other power usage (lighting, music, water pump etc)
How often do you intend to drive?
Is this for weekends away, a couple of weeks away or longer?

The two name brands are Ctek & Redarc.
I have no experience of the Ctek, but others who have them are happy with their purchase.
I have a Redarc & am happy with my purchase.

Here is the Redarc range (http://www.redarc.com.au/products/category/4wd-dc-battery-chargers/) (ignore the prices, they can be bought a lot cheaper). The size which would suit you best depends upon the answers to the questions above.

A larger amperage unit will bring the charge of a depleted battery up to around 70% more quickly (less driving time) than a smaller amperage unit, but to get that all important top 30% into the battery will take the same amount of time regardless of the amperage of the charger, so choice is dependent upon how much you expect to take out of your trailer battery between (percentage of battery capacity) driving with the trailer attached.

eg. if driving (with trailer attached) all day most days it is likely that a smaller unit would do just as well as a larger one, but if stopping for a couple of nights at a time & taking more out of your battery, & then only driving (with trailer attached) for half a day a larger unit may be better.

In my case my batteries being charged by the Redarc 40 amp charger are 3 x 120Ah, possibly being taken down to 50% capacity over several days. In my case it makes sense to have a larger unit because the batteries would be able to accept the full 40 amps for 3 hours plus in such circumstances, & a reduced charge until full for the rest of the driving day. Most of the time my batteries would not be taken down to 50% (using solar) & the full capacity of the charger not used, but the set up takes into account worst case scenarios, much more important if full time on the road.

Cuppa
Hmm O.k Trailer battery is said to be a 100AH.
Uses will be a fridge 75L Combi, specs say it draws 4.2amps maximum. Also running a small water pump for the kitchen tap and a couple of led strip lights (Which we don't leave on at night, only turn them on when we need to)
Music via my car...
Usage would be weekends and longer stays...
I do have the portable solar setup too but like I said I am considering selling it as its bloody massive, 3 panels hinged together, and heavy and getting something smaller and easier to carry. Either that or I will separate the panels so I can move them around individually. dunno yet...


Hugely depends on the weather, I've only got a cranking battery in mine and in winter my 40L fridge can run for a week and I can still start the car, but in warmer season it will be flat after 3 days.
My cranking battery is just that, a cranking battery. Apart from the radio everything else runs of my second aux battery.
Its funny how say ten years back I had everything running off a 9KG gas bottle. Now I only use a 2.5kg bottle and that lasts me all year... How times have changed.

[mudski]

I just got off the phone with the guys at Redarc. As I had my eye on the BDCD1220. He asked if I had solar panels. I do, so he advised I go for the BCDC1225 which is 25A and has a built in MPPT solar regulator. So the hunting begins....

[Cuppa]

I just got off the phone with the guys at Redarc. As I had my eye on the BDCD1220. He asked if I had solar panels. I do, so he advised I go for the BCDC1225 which is 25A and has a built in MPPT solar regulator. So the hunting begins....

Here ya go.
http://www.ebay.com.au/itm/REDARC-BCDC1225-DUAL-BATTERY-ISOLATOR-SYSTEM-DC-TO-DC-MPPT-SOLAR-4X4-4WD-AGM-/300914060803?pt=AU_Car_Parts_Accessories&hash=item460fe02e03&_uhb=1

Seller is an authorised Redarc reseller. beware of others on ebay who are not. Redarc will only honour their warranty if the item is purchased from an authorised reseller. If an ebayer says 'return it to me if a warranty claim is required" forget it & look elsewhere. If purchased from an authorised reseller you deal directly with Redarc if there is any problem.

Cuppa
Ps. make sure you don't get a BCDC1225LV

[BigRAWesty]

I just got off the phone with the guys at Redarc. As I had my eye on the BDCD1220. He asked if I had solar panels. I do, so he advised I go for the BCDC1225 which is 25A and has a built in MPPT solar regulator. So the hunting begins....

Do your panels have a built in reg? If so there is no need for the 1225. Just connect your panels to the battery..
Father in-law has just gone threw the same thing now thinking about it..
He was looking at the c-tech equivalent of the 1225 A's he has an 80W pannel, but went the standard as the panel is regulated. He decided against cutting the reg Off as it is handy for the car when the trailer is not in tow.

[mudski]

Here ya go.
http://www.ebay.com.au/itm/REDARC-BCDC1225-DUAL-BATTERY-ISOLATOR-SYSTEM-DC-TO-DC-MPPT-SOLAR-4X4-4WD-AGM-/300914060803?pt=AU_Car_Parts_Accessories&hash=item460fe02e03&_uhb=1 (http://rover.ebay.com/rover/1/705-53470-19255-0/1?campid=5336709507&toolid=10001&mpre=http%3A%2F%2Fwww.ebay.com.au%2Fitm%2FREDARC-BCDC1225-DUAL-BATTERY-ISOLATOR-SYSTEM-DC-TO-DC-MPPT-SOLAR-4X4-4WD-AGM-%2F300914060803%3Fpt%3DAU_Car_Parts_Accessories%26 amp%3Bhash%3Ditem460fe02e03%26amp%3B_uhb%3D1)

Seller is an authorised Redarc reseller. beware of others on ebay who are not. Redarc will only honour their warranty if the item is purchased from an authorised reseller. If an ebayer says 'return it to me if a warranty claim is required" forget it & look elsewhere. If purchased from an authorised reseller you deal directly with Redarc if there is any problem.

Cuppa
Ps. make sure you don't get a BCDC1225LV
I can get Redarc products direct from a wholesaler cheaper than any Ebay seller so I'm right there...


Do your panels have a built in reg? If so there is no need for the 1225. Just connect your panels to the battery..
Father in-law has just gone threw the same thing now thinking about it..
He was looking at the c-tech equivalent of the 1225 A's he has an 80W pannel, but went the standard as the panel is regulated. He decided against cutting the reg Off as it is handy for the car when the trailer is not in tow.
Yes my panels now have a Suntrans 20A regulator on the back of the panels....This is where I am stuck now. The trailer we are buying comes with a kit supplied and fitted which has the Anderson plug and lead running into a charger of some sort. It's a Repco branded charger, and I don't know of the specs but I think it wont be much chop. But the charger supplied also has a 240V connection on it which maybe be for charging from 240V???
My two options here...


Too remove the already installed Repco charger and buy a Redarc charger BCDC1225
Leave the Repco charger in, and move my Suntrans reg from the panel and mount it in the trailer and somehow connect it into or along side the Repco charger...I'm not sure how this will all work though...

[BigRAWesty]

First up, details on the repco charger.. You may not need to spend a cent..
But why remove the reg?? Why limit your panels to only charging the trailer. I'd leave reg on panels to allow solar charging of any battery me matter where it lays..

[mudski]

First up, details on the repco charger.. You may not need to spend a cent..
But why remove the reg?? Why limit your panels to only charging the trailer. I'd leave reg on panels to allow solar charging of any battery me matter where it lays..

Having the reg as far away from the battery isnt ideal. Plus having the reg under the panel it gets hot quicker and therefor will cut out earlier. So I have told anyway... as for specs on the Repco charger, I have failed to find anything on their website. I might have to just wait until I get the trailer, then worry about it. Not what I want but....

[janderson]

this may help

[mudski]

this may help

I have that but am unsure how the setup will be on the trailer though. Or how I can use their set up and add too it.

[Cuppa]

Any reg supplied stuck on the back of the panel is going to be cheap junk & is best replaced. Even if it was any good, which it isn't, being stuck on the back of the panel is not a good place. It will read the output from the
the panel rather than what is actually reaching the battery, which is likely to be less because of cable losses. A better quality regulator would treat your battery better & help it last longer.
The Repco charger, if it has a 240v lead is a mains charger, intended to be used where you can plug into mains power (i.e.. at home or in a caravan park). It may be convenient to retain the Repco mains charger, but it wont do the job of an in car charger, (dc to dc), nor will it do the job of a solar regulator. The BCDC1225 will do both, do it well, & provides an 'elegant'solution. You could leave the regulator on the back of the panels for emergency use should you ever need to get some charge into another battery like Kallen suggests. Just disconnect it & reconnect should you ever want to use it.

Cuppa

[mudski]

I dunno cuppa as this Repco charger did have a connection on it to connect up an Andersons plug and lead to charge from the car aswell. So it can charge both via the car and 240v. How I would add a BCDC1220/ 25 into the mix is another question.... Still trying to find specs but the Repco site doesn't show squat.

[mudski]

All it says on the trailer spec sheet is 12v/12Amp 240Volt Mains charger....Why doesn't Repco show any specs of their products on their website. Hopeless.

[Cuppa]

I'm 99% sure it'll just be a mains charger. A 12 amp one for a 12v battery.
If I'm correct there is no reason why you can't connect the BCDC to your battery as previously mentioned & leave the Repco charger connected to it as well. Plug in to the mains when available, charge whilst driving, & connect solar when camped out in the bush. Use the mains charger you already have at home to charge your crank battery (& aux battery via the SBI12).

Cuppa

[BigRAWesty]

Yea fair call on the solar panel reg guys.
You mention you wanna sell that Anyway mudski so yea, 1225 it up and grab an unregulated panel, will be cheaper..

But running the repco 240v charger and the redarc side by side is easy.. You just connect both to the battery..
If your worried about back current into either of the 2 chargers run either isolators or plugs on the battery side of them but I don't think that's necessary.

[mudski]

I'm 99% sure it'll just be a mains charger. A 12 amp one for a 12v battery.
If I'm correct there is no reason why you can't connect the BCDC to your battery as previously mentioned & leave the Repco charger connected to it as well. Plug in to the mains when available, charge whilst driving, & connect solar when camped out in the bush. Use the mains charger you already have at home to charge your crank battery (& aux battery via the SBI12).

Cuppa
Unless they are using this Repco jobbie just for mains and nothing for 12V??? Direct from the Anderson plug to the trailer battery? Might have to wait until I get the trailer maybe to see exactly.

[megatexture]

If its a mdc trailer its a 240 - 12v charger for caravan parks and storage as a mate has just bought one .

[mudski]

If its a mdc trailer its a 240 - 12v charger for caravan parks and storage as a mate has just bought one .

You dont happen to know the specs of the charger?

[megatexture]

Aha, so the ctek in the car 'sees' the three batteries as a single unit. How do you manage when camped but have disconnected the vehicle from the camper to go off for a drive? I would wonder if there might be occasions when you want to hook up & drive, immediately after a drive without the camper connected. In which case the aux battery would be fully charged, but the camper batteries would be depleted (from running the fridge etc whilst you had been off driving without the camper). Most times this wouldn't be an issue as given time the three batteries would balance themselves once reconnected. But what happens when you reconnect & drive away immediately? would't the ctek see the aux as charged & not in need of charging, not charging the camper batteries until the voltage in all three had dropped (balanced). This may not be an issue, but I can imagine a possibility where on occasions you stop set up camp & find the batteries are not as fully charged as you need? I suppose it depends upon how quickly the batteries balance themselves & how long you drive for & how long you intend to camp without driving again (The capacity of three batteries would likely give a reasonably sufficient 'buffer' if the next stop was only a short one & the sun was shining). Those three factors could make it a non issue for you, where for some it may be. A fine example of how 'pattern of usage' varies what will work for some & not others I suspect, & a reason to always ask what the pattern of usage is as well as 'what does the user want to run'?

Cuppa

I've got dual volt gauge on the car and a single on the trailer that I regularly monitor and Can't say I've seen my batteries lower than 11.9, average would get down to 12.2 over a week, that's running a 80l and a 40l Waeco and lights when needed. I do put the solar out ASAP and if camped and I'm not going for a day trip I plug the trailer to the car with 2x 10m extension leads depending on how close I can get the car to the trailer. only once have I needed to run the car to top up the batteries and that was only due to bad weather before we were told to evacuate the beach.

[megatexture]

You dont happen to know the specs of the charger?

Ill see if I can find out for you

[megatexture]

Here is a pic of the unit fitted inside his toolbox , it had no specs on it that he saw unless its printed on the back but from what I can see this is the same unit. My mate has also put another batt infont the one you can see in the bottom of the pic.

http://www.biasboating.com.au/Powertech_12_Volt_12_Amp_Battery_Charger_p/3234.htm

[mudski]

Here is a pic of the unit fitted inside his toolbox , it had no specs on it that he saw unless its printed on the back but from what I can see this is the same unit. My mate has also put another batt infont the one you can see in the bottom of the pic.

http://www.biasboating.com.au/Powertech_12_Volt_12_Amp_Battery_Charger_p/3234.htm
Thanks for the info mate. I'm just trying to figure out how they have the 12v charging setup then. I assumed this charger they supplied does both. But it looks like it doesn't.

[megatexture]

Na they just have an Anderson plug to the batt and the charger to the batt also , then running off the battery is a aim fuse going to a small fuse box then splits off to cig plugs . Its a basic setup but easy to add to also

[megatexture]

Just sent him a txt and its definitely only a 240v charger

[mudski]

Thanks for the info. Much appreciated.

[mudski]

Ok. Finally got the trailer last weekend. Now. I have run the cable from front to back of the car and put an Anderson plug on it to connect to the Anderson on the trailer. Still a tad confused whether I can hook straight up to the cranking battery in the car direct (no dc to dc charger). Can afford one right now so it has to wait.
Am I ok to go directly to this battery for now? Should I run a fuse inline aswell? If so what size?
Thanks

[threedogs]

I ran some 8mm from my AUX battery to rear bumper terminating with a 50 amp Anderson with a thermo fuse at battery end.
In the end I could of just ran some 6mm from the rear power outlet, but works a treat self contained so to speak.
This charges the battery in my camper as well as my AUX in 4x4. as long as alternator is 100amp you should be fine charging three batteries
I like to leave the start battery alone and leave it for starting only, one less thing to go wrong

[megatexture]

You can run straight from the starter temporaraly just rember to unplug it when ou get to camp so you don't drain it or if you have an isolator/ dual batt set up put it on the aux batt in the car

[mudski]

Do I need to run an inline fuse?

[megatexture]

Probably should though I haven't as of yet but I do have a mega fuse waiting for when I get time. Mines twincore insulated and in split tube in the chassis rail till the rear wheel so I didn't bother but I will be.

I have a thermal circuit breaker on the camper in the tool box.

[Matt195583]

I read through a few pages of this and thought I might be able to offer some advice.

If you hook 2 or 3 battery banks up via a VSR you will greatly decrease the life of your batteries as when hooked up the battery in the worst condition will cause the alternator to over charge and kill the better batteries. You really need a Dc to Dc charger to manage the charging. I've had this happen on my boat which has one start battery and two house batteries together, one of the house batteries was replaced just be fore I bought it and within a year that new battery was shagged due to over charging.

[mudski]

Yes I know I need a dc to dc charger but I wanted to know if I could hook it up direct for now. Then I'll fit the charger later.
cheers.

[Yendor]

Yes you can. Just remember it won't fully charge the battery in the camper.

I would make sure the camper battery is fully charged before you leave and put it back on charge again as soon as you get home.

For safety, fuses or circuit breakers should be used. The fuse is there to protect the wire, so use fuses suitable for the rating of the cable.

[mudski]

Thanks bud. This is just so i can get it working, not as it should but working in the meantime. I have a 30amp ciruit breaker sitting here. Would that be efficient for 5mtrs of 8b&s cable?

[Yendor]

That should be fine. If you had to go out and buy one I would say make it a 40amp.....the 30 amp should do the job.

Should also be fused at both ends.

[mudski]

Thanks. Should I run one of those massive inline fuses that people use on their car amps. The clear jobbies with the gold plated fuse. The only reason I'm asking is because of the cable I'm running. 8b&s. I might see whats available at Jaycar too. I need something that can accommodate the larger cable.

[Winnie]

I used a 40A maxi fuse for 8mm cable.

[Yendor]

Thanks. Should I run one of those massive inline fuses that people use on their car amps. The clear jobbies with the gold plated fuse. The only reason I'm asking is because of the cable I'm running. 8b&s. I might see whats available at Jaycar too. I need something that can accommodate the larger cable.

That's up to you if you want to spend the money. Either will work fine.

With 8B&S you should be using battery lugs.

[threedogs]

I have plenty of large lugs here if you get stuck.

[mudski]

That's up to you if you want to spend the money. Either will work fine.

With 8B&S you should be using battery lugs.
Yeah I will be using lugs and I'll sweat solder them in.