Dual Batteries or one single

[Mitch.mccabe]

So for our camping needs, we might go 3 days without power( would be charging every 3 days, so I want to figure this out with your help and Please mind my lack of expertise in this area, So here is a question could you wire 2 x 95 amp batteries to give 190 amps, instead of using a single 130, thus giving more ampage? Would you have to run the 2 95's with a dual battery system or just a smart charger. A local nrma here in town, sell new 95amps for $130, they don't sell anything bigger,
Any thoughts or ideas would be good, I would be running lights, maybe some tunes, a water pump and maybe a fridge

[happygu]

Mitch,

I can flatten my battery in one day, by just having the radio on whilst working on the truck....

I would definitely look at the dual battery option, especially with a fridge on board - or at the very least, some sort of solar panel for daylight charging whilst you are still.

I have a dual battery system, so my natural inclination is to head for that and I have never been stuck ..... but we will see what the others say too

[threedogs]

If those 95ah batteries are out of an UPS, or for one leave them alone , they will rattle to bits
All I use is a 115 AH wet cell Trojan and an 80watt solar panel, its simple and it works.
This battery runs my 40 ltr Engel and some LED lighting which pulls very little power.
As I said been using this set up for 20 years and NEVER ran out of battery.
I have a camper with a 100ah battery for tunes at camp and additional lighting if need be.
Keep it simple.
I take an Ice box for every ones cool drinks, Engel only for food,
a good ice box will retain Ice for 3 days easy imo. If travelling you'll need fuel every day so you can top up ice as well
Water pump wouldn't be running for any extended periods I would think.
If those 95 batteries are ok you could install one under the bonnet ,
the other you could put in a plastic battery box, this way you can move your lights to say down by the river

[Drew]

Just remember that if you charge solely by the alternator they won't be fully charged so best use solar and/or a smart charger to get the most out of your batteries.

One setup I saw was have 1 battery under the bonnet topped up by portable solar panels and the 2nd battery charged while driving using a 240v smart charger via an inverter.

Maybe a ctek d250s that can be used to charge using panels and when driving its a dc/dc charger (no need for an inverter running in the car)

[Mitch.mccabe]

Sorry I probably should have mentioned that this is for my camper, I will be getting a decent system in the patrol,
So every 3 days I would be able to charge the batteries in the camper

[threedogs]

No problems then , a bit of LED lighting will use very little power.
later on get a dc to dc charger

[Cuppa]

At 12v 2x95Ah in parallel will give a total capacity of 190Ah (Amp hours, not amps).

If your batteries are 100% charged this will give you a useable capacity of about 100 AH, (less if you are drawing large currents from it). It is possible to use more, but if you take the batteries below 40/50% capacity you will be severely reducing their lifespan each time you do.

However as Drew says your alternator alone will not fully charge your batteries, it will only charge them to about 70% capacity, or 75 to 80% capacity for AGM’s.

Lets be generous & say you have new AGMs & that your alternator can get them to 80% capacity. This means you would have an effective total capacity of 152Ah. If you discharge them to 40% (of 190Ah/76Ah) this gives you a useable capacity of just 76Ah. (152Ah - 76Ah = 76Ah). So by following Drew’s advice & fitting a dc to dc charger & thus being able to fully charge your batteries you gain an extra 25% useable capacity, as well as ensuring that your batteries will have a much longer lifespan.

Ctek & Redarc both make good dc to dc chargers.

[Drew]

Cuppa always the literary genius :), couldn't have said it better myself suck suck grovel grovel :)

I have 240Ah in the van, charged with a DC/DC charger while on the road, can connect solar to it if I want (same charger) and then if I really need to, kick the genny in the guts and stick the 25A charger on it. Did you see the pic TD :P

Ultimately it comes down to what you connect up. I use a CPAP so that takes 20-30Ah (amp hours) out a day (or night) or even more if i have a nanna nap :). That's why I'm a bit fussy coz if I run out of juice I don't sleep. As TD says, LED's take nothing.

So for me at 240Ah & CPAP & lights I could squeeze 3 nights out before I hit 50% charge and need to charge (Assuming batteries were at 100% at the start). 5-6 nights with 120w portable solar panels charging during the day. If the batteries were at 80% then I lose a night :(

As far as what/how many batteries it comes down to what you run off them, for how long and how long you want to go before charging.

The other thing is what space you have and type of battery. I have sealed AGM in the van and can lay them on their sides if need be. I don't know where you are but guys like Batteries Direct deliver to most places I think so don't limit yourself if you can avoid it.

Just remember what Cuppa said, there's total capacity then there's usable.

This might help http://www.fridge-and-solar.net/agm.htm

[Mitch.mccabe]

Wow this is all mainly going over my head lol. Those weblinks are an awesome read Drew. Thanks aswell Cuppa, I have read quite a few of your posts and you seem very much in the know for auto electrics/batteries.
I think with what I'm going to be using in the led lights, and being able to use either 240volt ctek smart charger or my genie every 2-3 days I don't think I would go under the 50% capacity. Although may come close.
I'm going to get ARB to hook up a dual battery system up in the patrol with a better rated 12 volt plug for the fridge in the back( as I've read that the standard 12 volt cord/plug to the rear may be a little under powered for a full time fridge when it is on) , and also hook up a Anderson plug. (for a later date. To be able to charge the batteries in the trailer whilst we are driving)
My only problem might be with my genie, I only have a 1kva inverter genni, Would that be enough to use the ctek charger to charge the batteries? I read most of this link http://www.fridge-and-solar.net/gen_charge.htm but couldn't find out how big a genni I'd need
Also can you use the power (leds) as your charging the batteries?
Any more answers would be great if you can understand what I'm saying,
P.S Cuppa, How good is Copeton Dam

[Cuppa]

My only problem might be with my genie, I only have a 1kva inverter genni, Would that be enough to use the ctek charger to charge the batteries? I read most of this link http://www.fridge-and-solar.net/gen_charge.htm but couldn't find out how big a genni I'd need
Also can you use the power (leds) as your charging the batteries?


The 1Kva gennie is fine for use with a multi stage battery charger. I have a Honda Eu10i 1Kva which I bought in a rash moment & have only used it when our bus alternator died a long way from anywhere. I used it to charge our crank batteries every two or three days via a Ctek 14Amp/24v charger (equivalent of 25amp/12v Ctek) without any difficulty until I could get a replacement alternator sent to Broome).

Yes you can use power whilst charging.

If you are going to change plugs for the fridge (a good idea) replacing it with an andersen plug gives the most secure connection.

We enjoyed Copeton Dam, but it was bloody freezing when we were there, got down into minus temps. great whilst the sun was out, but like a freezer as soon as it went in.

Val at Fridge & Solar who wrote the article you linked to is a good mate of mine, top bloke always willing to help folks out.

[megatexture]

Save your coin at arb and wire it up yourself, that way you know how its set up in the event you may need to trouble shoot a problem in the future. its actually verry simple to do! Also you will have no shortage of info to help you along if needed.
if you plan to get a dual batt set up I would recommend a dcdc charger with built in solar regulator like ctek's ( my choice) or a red arc unit. The ctek is rated at 20amp can take up to 250w of solar pannel and capable of maintaining a battery bank of up to 300 amp, and who knows you may not need to run your genni .

[lucus30]

Save your coin at arb and wire it up yourself.

X2 do it yourself. I just did mine

[Cuppa]

A local nrma here in town, sell new 95amps for $130, they don't sell anything bigger,


That price sounds cheap if it is for 95Ah batteries. This leads me to suspect that they are most likely ‘wet’ batteries, & possibly not deep cycle?
For the use you are planning deep cycle batteries are the go. Cranking batteries will work, but will have a shorter lifespan.

If I’m correct & they are ‘wet’ batteries ...... DO NOT mount them inside the vehicle. Wet batteries when being fully charged on a smart charger (unlike when being only alternator charged) will bubble & release gas. You don’t want that inside your vehicle. It stinks & is unsafe. You will also need to regularly check their fluid levels & top up with distilled water.
AGM batteries can be placed inside the vehicle, don’t need topping up & are quicker to charge as a bonus.

[Drew]

Wow this is all mainly going over my head lol. Those weblinks are an awesome read Drew. Thanks aswell Cuppa, I have read quite a few of your posts and you seem very much in the know for auto electrics/batteries.
I think with what I'm going to be using in the led lights, and being able to use either 240volt ctek smart charger or my genie every 2-3 days I don't think I would go under the 50% capacity. Although may come close.
I'm going to get ARB to hook up a dual battery system up in the patrol with a better rated 12 volt plug for the fridge in the back( as I've read that the standard 12 volt cord/plug to the rear may be a little under powered for a full time fridge when it is on) , and also hook up a Anderson plug. (for a later date. To be able to charge the batteries in the trailer whilst we are driving)
My only problem might be with my genie, I only have a 1kva inverter genni, Would that be enough to use the ctek charger to charge the batteries? I read most of this link http://www.fridge-and-solar.net/gen_charge.htm but couldn't find out how big a genni I'd need
Also can you use the power (leds) as your charging the batteries?
Any more answers would be great if you can understand what I'm saying,
P.S Cuppa, How good is Copeton Dam

I bow to Cuppa he's the exspurt ;) :)

Seriously mate, I hear you. It took me months before I did this the first time around and then oh wait took months the second time coz I couldn't my head around some stuff and being the Patrol and not the Navara, it was a little different. Enough to stop me.

When it comes to the car it's piss easy. oh am I allowed to say that ? easy ? :) As said, save some coin and do it yourself. The second battery, decide on which isolator (ton of options there sorry) get the cables mount, screw, done.

Running the power for the trailer, the way I did it, 6B&S cable, auto resetting fuse, relay (to prevent power going to trailer when ignition isnt on), plugs, connectors, cable ties and roll around on your back putting it all in.

Power to the cargo area, see my thread.

I am not a technically minded person, I couldn't tell you arthur from martha before I did mine but it is not as hard as it first seems. There are heaps of wisdom well knowledge here and really the difficult bit is choosing the kit and wondering if it's the right choice.

So to cut it short, stick the best battery you can afford in the trailer (something that can handle a bit of rough stuff), LEDs will draw bugger all so 3 days won't be a problem and if need be charge at home. If need be, as cuppa said a 1kva genny will be fine. Geez I've used mine more with power outages at home than camping :).

The next decision is whether you need 2nd battery next or run power to trailer. I'd go 2nd battery for peace of mind and fridge maybe, then power to trailer.

oh and keep in mind that if you do need to charge with the genny, the size of the charger (Amps) does matter. :) Well time wise that is. A 25Amp charger (or cuppas wiz bang charger) is way faster than a 7Amp. 20/20 hindsight, I should've saved a little and got the 25Amp I just got instead of the 7amp 2-3 years ago.

I must've missed it, where are you located mitch ?

[the evil twin]

So for our camping needs, we might go 3 days without power( would be charging every 3 days, so I want to figure this out with your help and Please mind my lack of expertise in this area, So here is a question could you wire 2 x 95 amp batteries to give 190 amps, instead of using a single 130, thus giving more ampage? Would you have to run the 2 95's with a dual battery system or just a smart charger. A local nrma here in town, sell new 95amps for $130, they don't sell anything bigger,
Any thoughts or ideas would be good, I would be running lights, maybe some tunes, a water pump and maybe a fridge

Hi Mitch,

Because the setup is for your camper...

I run twin 105AH deep cycle batteries with a similar load to your useage (lights, water pump, 60 litre frig etc) however I do use Solar charging (not Genset) if I camp up for a period, soooo...

1. Due to the chemistry and physics of lead acid batteries two batteries (say 50AH x 2 = 100AH) in parallel will actually have a better useable capacity and longer life than an equivalent single (say 100AH).
They will take up more room and weigh more however.

2. I have a feeling that the 95 AH jobbies that the NRMA are selling may not be deep cycle and if they are I would therefore definitely not recommend them for the camper if you are running them 3 days between charge cycles.
If they are deep cycle and you watch your 'state of charge' (SOC) they will be fine.

3.If you go Solar many of the regs will tell you power useage etc. however, whether you do or you don't, there are many quite cheap power monitors that attach to the battery/s and will tell you the power you are using, voltage, capacity used etc.
I would definitely fit one as they are very valuable tool for keeping an eye on what is going on.

4. Be a tad wary of "technology solutions" and how you use them.
Some are brilliant, some are smoke and mirrors, some are brilliant but totally unnecessary.
The manuf advertising blurb and tech reps will try to sell you anything they make whether you need it or not.
Take "smart" battery chargers for example.
Even many of the top brands don't work correctly due to their algorithms and programming if there is equipment operating from the battery.
The presence of the load (esp high current intermittent loads like a water pump) confuses them in regard to the SOC and charge acceptance rates for what they think is a battery.

5. Try and firm up exactly how your system will work best for you and purchase the gear around that method and your budget as it permits.
So, get a power monitor, then
Solar - Good quality Reg and size the Solar Panels matching your battery useage (to small and you end up with no power, to big is pointless and expensive)
Genset or Mains - Good brand smart charger and, budget permitting, a power supply so you can charge the battery/s off load
Vehicle - DC/DC charger (mounted as close to the camper batteries as possible). As posted by others the good brand combo Solar / DC/DC jobbies are versatile and ost effective if used with Solar.

6. ALWAYS keep the camper batteries as close to fully charged as is practical when the Camper is not in use.
Batteries are a chemical device. The electricity is just a byproduct.
When the battery is not fuly charged the chemistry is such that sulphation etc is accelerated reducing the life and even more importantly the capacity of the Battery and the whole idea of the exercise is to have and keep as much available capacity as you can.

Bottom line is that 'simple is best' and as long as you aren't pulling your batteries down to a low SOC it is pretty hard to balls anything up.

[Ronin]

apologies for hijacking the thread.. but what do the experts think of this ? Ark Pak (http://www.arkcorp.com.au/p/3231/arkpak-12v240v-battery-box)

We go camping for like 3 days every two to three months. So dont wanna lug a battery in the Patrol all the time.

[the evil twin]

apologies for hijacking the thread.. but what do the experts think of this ? Ark Pak (http://www.arkcorp.com.au/p/3231/arkpak-12v240v-battery-box)

We go camping for like 3 days every two to three months. So dont wanna lug a battery in the Patrol all the time.

There are quite a few variations of that theme around but that is the first time I've seen that particular one.

Given your useage pattern then it will be fine and no better or worse than a hard wired installation
Essentially it will be as good as the Battery you put in it and they have gone for versatility with connectors etc so ticks a lot of boxes I spose.

Cost might be a bit of an eye opener

[Ronin]

There are quite a few variations of that theme around but that is the first time I've seen that particular one.

Given your useage pattern then it will be fine and no better or worse than a hard wired installation
Essentially it will be as good as the Battery you put in it and they have gone for versatility with connectors etc so ticks a lot of boxes I spose.

Cost might be a bit of an eye opener


yeah they are not cheap.. just the unit itself is 450 and u have to add a battery to it. But they do have all the connections I could need including a 240v output.

[megatexture]

yeah they are not cheap.. just the unit itself is 450 and u have to add a battery to it. But they do have all the connections I could need including a 240v output.

450$ sounds like a lot but if you were to make it yourself it adds up fast but I bet you would get a better unit at the end of the day. if you were to get a battery monitor also the ark wouldn't be such a bad option though mind you i added a bit on these prices as I'd be using baintech plugs and USB and cheaper parts could be used.

battery box $74 20 if you get a blank one
Merit,cig cig plugs 60
Anderson plug 20$
Inverter 60$- 300$
Dual USB plugs 65$
Ctek 7amp charger 145$ ebay
Isolator switch 30$

Around $450

[Ronin]

thanx for the reply Megatexture.

I was reading their FAQ (http://arkcorp.com.au/t/akpakfaq) and saw that they do not have Pure Sine wave inverter. Although they say its ok, but I am not entirely convinced.

----------------------------------------------------------
What type of inverter is in the ArkPak?

The ArkPak has a built in 150W modified sine wave inverter.


Will the modified sine wave inverter damage my electronic equipment?

Unfortunately there is a misconception about modified sine wave (MSW) inverters in the market; in short most portable electronic equipment that you will be using with the ArkPak while out camping, use a transformer which generally converts your home’s 240V AC power to 12V DC then charges the device. So whether you are using a Modified Sine Wave inverter or a Pure Sine Wave (PSW) inverter, the appliance’s transformer is giving the electronic device the necessary current and voltage it requires to operate safely.

[threedogs]

apologies for hijacking the thread.. but what do the experts think of this ? Ark Pak (http://www.arkcorp.com.au/p/3231/arkpak-12v240v-battery-box)

We go camping for like 3 days every two to three months. So dont wanna lug a battery in the Patrol all the time.
You may be better off building your own battery pack, I did. inside mine is an 18AH battery about the size of a motorbike battery.
It will last all weekend running my LED lights, I decent battery pack with different outlets cig,merit and Anderson should set you back around $100.
or buy a plain one and fit all plugs etc yourself

EDIT::::: must fit a USB port to it in the future, already have one inside the Patrol

[Mitch.mccabe]

So I went down to our local tyre shop, they can get batteries, and he is pricing me up a 145 or 160ah deep cycle. Might have a look at these 160w solar deals on ebay, and a ctek 25amp smart charger. Should be set then, just have to make up a small simple controller/accessories box, If anyone else has any pics of their set ups, please feel free to put them on here.
P.S threedogs, I got to use your front recovery points a couple of weeks ago, getting my mate and his paj out from sloppy mud up to his axle!!!! Sweet as

[Mitch.mccabe]

Drew, I'm in lightning Ridge, nsw atm

[the evil twin]

Drew, I'm in lightning Ridge, nsw atm

I have had some AWESOME short term memory losses there (nearly friggin' drowned in the Tank one night)

[Drew]

Drew, I'm in lightning Ridge, nsw atm

Noice, I'll get there one day :)

[Mitch.mccabe]

http://www.onlinebatteries.com.au/crown-supreme-cr165-p-409.html

Does this look allright or something smaller?

[Drew]

http://www.onlinebatteries.com.au/crown-supreme-cr165-p-409.html

Does this look allright or something smaller?
Um are you aware that's an 8volt battery ? TBH I didn't even know they made them.

Are you looking for a deep cycle or AGM ?

[Mitch.mccabe]

bahahahaha howd I get that wrong?

[Drew]

bahahahaha howd I get that wrong?

Dunno but my excuse is oldtimers :)

[Mitch.mccabe]

42190Oh yeah, some toys rocked up this afternoon, 3 days until I get the camper, and then let the games begin

[Mitch.mccabe]

http://www.ebay.com.au/itm/130AH-AMP-HOUR-BATTERY-AGM-SLA-12-VOLT-12V-DEEP-CYCLE-DUAL-FRIDGE-SOLAR-/400634846771?pt=AU_Car_Parts_Accessories&hash=item5d47b29e33 what about this one??

[lucus30]

http://www.ebay.com.au/itm/130AH-AMP-HOUR-BATTERY-AGM-SLA-12-VOLT-12V-DEEP-CYCLE-DUAL-FRIDGE-SOLAR-/400634846771?pt=AU_Car_Parts_Accessories&hash=item5d47b29e33 what about this one??

I think that one would be ok and knowing that seller and his turn over rates it should be relatively fresh stock. The thing will be heavy though.

Might be better to head to a retail outlet like battery world or something though

[Drew]

Free Freight. Trustworthy seller. Just not sure about the brand, never heard of them but that doesn't mean much:)

[Ronin]

a bit heavy at 32.5 KG.

[Drew]

Not unusual for that size/type of battery. Lucky he's got a patrol :)

[the evil twin]

Free Freight. Trustworthy seller. Just not sure about the brand, never heard of them but that doesn't mean much:)

I buy a fair bit of gear off that seller... never been disappointed yet.

Jeeez that looks like a Full River case... might be a knock off 'cept the discharge ratings are higher so maybe not.
The weight is good (I can barely lift the bloody Full Rivers I use) the lighter the battery the crappier it is in the Lead Acid technology

I'd be happy enough to buy it.

[Mitch.mccabe]

42907 Battery arrived today, now I can start to figure out how I'm going to set it all up

[Mitch.mccabe]

Whats everyones thoughts on voltage meters? They seem cheap, so are they worth it, I just dont want to guess and stuff the battery by undercharging or overusing, If yes, then what are your suggustions?

[megatexture]

I've got a baintech dual volt meter and its easy to see and is backlit I looked around a bit and this was the best IMO and I like a digital readout that displays .1 of a volt not a needle to keep me guessing http://www.baintech.com.au/meters-monitors/baintech-voltage-voltage-meter-surface-mount

From memory it was like 60-70$

[Cuppa]

Using a voltmeter as a battery 'fuel gauge' is fraught with problems. It can give an indication ofa battery's state of charge but only in certain circumstances to someone who is a little knowledgeable about such things. Some people sell them, telling folks that x voltage equals a specific state of charge. Unfortunately trusting folks accept this, but it just isn't true. Such readings require a battery to be rested (no load or charge for a minimum of half an hour & preferably several hours), which virtually never happens. Where voltage readings are useful is to assist the user in becoming familiar with their setup & thus being able to recognise what is normal & able to be aware of any deviations from this. For the majority of folk this isn't very practical because they simply don't spend enough time on a regular basis with the system to establish that familiarity. We lived & travelled in our bus for 18 months, & every morning when I got up in the early hours, before dawn, for a pee i would check the voltage readout on the solar regulator. Doing this gave me a very good idea of what was 'normal', & if it was lower than usual, i could predict it because, for example I knew the previous day had been cloudy, or we had watched a lot of tv the previous night. Such familiarity enabled me to know if we ever had a problem, & gave me a reasonable idea of the relative state of charge.

There is no perfect way to measure state of charge because batteries are based upon chemical reaction. However the most accurate type of battery gauge (& what most people want, & unscrupulous sellers let them think they are getting with a voltmeter) is an ammeter installed with a shunt. The battery monitors basically keep count of amp hours in & amp hour out & with the full capacity of the battery set by the user, are able to tell them how full/empty the battery is most of the time. I say most because certain conditions will still cause false readings, but overall it is the most accurate method available. Unfortunately such battery monitors are several hundred dollars to buy.

I tend to observe the PWM function readout on my solar reg as a means of monitoring when my batteries are getting full during the day. PWM is shown as a percentage of available input from the solar panels being 'allowed' through to the nattery. As the battery becomes more full the percentage drops. Once down to 10% or less I know the batteries are close to full. Once full they go into 'float' mode, which tells me they are full, although most of the time this does not occur because the loads from the fridge & freezer cut in & prevents float occurring, but I'm happy enough to see the single figure PWM percentages by around 1pm each day.

Of those Baintech meters, the voltmeter alone is really doesn't tell you much of use. Their voltmeter ammeter is much more useful. In conjunction with showing battery voltage, it shows amps coming in/going out in real time. This means that if you know how many amps to expect to see coming in when the battery is discharged you can see this figure drop as the battery becomes fuller, & after a short amount of familarising yourself with the norms, you can make a reasonable judgement about how full the battery is by how many amps it is accepting.

[megatexture]

Yea if I was going to be that concerned i would buy a management system. Though with everything I have running off my batteries I don't expect my batteries to reach full charge during the day, I just like to see either that my alternator or solar panels are functioning correctly and that my batteries don't go below 11.8 and are above 12.2 minimum after dark if so I adjust my consumption.

[Cuppa]

Sounds like you have the familiarity with your system that I referred to MT.

In my case (in the bus - haven't used the Patrol enough to gain that familiarity yet) I expect to see the battery voltage at 12.6 or 12.7 after dark without the fridge cycling on. Most mornings before dawn & with the fridge not cycling on I expect to see 12.4v or 12.5v. Lowest it has ever been is 12.3v (reg has history since installation) & that was after a week of poor solar weather. My wife has been living in the bus for the past 3 weeks & has been recording these voltages & they are still remaining pretty constant, not bad for batteries & panels now approaching 9 years old!
This is a standalone solar system 300ah/375w running a 130 litre fridge, water pump, extractor fan, lights, radio/cd, phone & computer charging via an inverter & satellite tv via another inverter.

[Mitch.mccabe]

Thanks Cuppa, I knew you would spell it out for me in an easy to understand way, Since i'm really only using Led lights, and maybe a Waeco fridge, then my 130 amp hour AGM battery shouldn't get to stressed.
Cuppa, With the AGM batteries are you only suppose to run them down to half? so i would only have 65 usable amp hours when it is full. Is that correct?
I remember seeing a chart somewhere or calculator? for energy consumption?

If i can have the solar system on every afternoon and can use the 240v 25amp ctek every 5 days or so to fully charge it up I shouldn't have an issue.

I'll put up some pic during the construction of my battery box, Still trying to decide whether i'm mounting it under the bed in the camper, or buy a new lockable box and mount on the front of the camper?

[Cuppa]

Yep, 50%. They can handle 40% reasonably well, the important thing is not to leave them in a discharged state, if you can recharge within 24 hours you should ensure a long life. One reason (there are others) I have more battery capacity & the means of recharging them on a daily basis is so that they dont generally get discharged below 70% which should make them last even longer. 50% is a reasonable compromise. Your plan of attack sounds pretty reasonable given the space & weight constraints in a 4wd.

Given the battery weight of 35kg to 40kg keep your camper's weight distribution in mind when deciding where to put it. Also make sure you have sufficiently heavy cables between battery & fridge. Many fridge problems are caused by too light supply cables causing voltage drop & use circuit breakers rather than fuses. (Just lately I have heard several accounts of melted cables, one causing a fire, resulting from blade fuses which developed 'high resistance' without blowing).
Also don't use the thin cables supplied with many solar panels, invest in some thicker ones. There are charts on the net to suggest what gauge wire to use with what size panel/cable length. http://hobohome.com/news/?p=581

Whilst I'm at it here is a rather neat, easy to understand explanation of why voltmeters are not a reliable means of determining a battery's State of Charge I came across whilst looking for that solar wire gauge table. I thought it worth sharing. http://hobohome.com/news/?p=685

[Mitch.mccabe]

http://www.ebay.com.au/itm/281162804550?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 Cuppa this is the solar unit I bought, I know you cant see the cable size, but shouldn't I just be able to hook this up straight to the battery? I was going to change the clips (of the solar unit) with an Anderson plug so when I'm charging the battery I can disconnect from everything else. I might draw up a bit of a diagram and post it on here to see if I'm on the right track or if I'm going to zap myself. haha,
By one of those tables , I have 160 watt solar panels, with a 5 mt cable , so I'd need to make sure that the cables are 4mm? is that right?

[megatexture]

Bit deals panels aren't too bad, a few mates have them but you will still benefit from a wire upgrade. I'm running 8mm on mine and I have 2x 10m (if needed but rarely used)extensions as overkill because not every campsite is ideal. Work out the recommended and add to it IMO, but that panel has got a reg though probably not a great one but it can go straight on your battery.

[Cuppa]

http://www.ebay.com.au/itm/281162804550?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 (http://rover.ebay.com/rover/1/705-53470-19255-0/1?campid=5336709507&toolid=10001&mpre=http%3A%2F%2Frover.ebay.com%2Frover%2F1%2F705-53470-19255-0%2F1%3Fcampid%3D5336709507%26amp%3Btoolid%3D10001 %26amp%3Bmpre%3Dhttp%253A%252F%252Frover.ebay.com% 252Frover%252F1%252F705-53470-19255-0%252F1%253Fcampid%253D5336709507%2526amp%253Btool id%253D10001%2526amp%253Bmpre%253Dhttp%25253A%2525 2F%25252Frover.ebay.com%25252Frover%25252F1%25252F 705-53470-19255-0%25252F1%25253Fcampid%25253D5336709507%252526amp% 25253Btoolid%25253D10001%252526amp%25253Bmpre%2525 3Dhttp%2525253A%2525252F%2525252Fwww.ebay.com.au%2 525252Fitm%2525252F281162804550%2525253FssPageName %2525253DSTRK%2525253AMEWNX%2525253AIT%25252526amp %2525253B_trksid%2525253Dp3984.m1497.l2649) Cuppa this is the solar unit I bought, I know you cant see the cable size, but shouldn't I just be able to hook this up straight to the battery? I was going to change the clips (of the solar unit) with an Anderson plug so when I'm charging the battery I can disconnect from everything else. I might draw up a bit of a diagram and post it on here to see if I'm on the right track or if I'm going to zap myself. haha,
By one of those tables , I have 160 watt solar panels, with a 5 mt cable , so I'd need to make sure that the cables are 4mm? is that right?

Hi Mitch,
I would agree with what MT has said. Rich panels are of reasonable quality, but like all of the panels being sold cheaply on ebay there are major compromises in the bits they include with them. IMO you buy the panel with the view that the other bits are throwaway items. Considering how much the cost of panels has dropped I can live with that. The kyocera 125w panels i have on the roof of our bus cost me over $1100 each almost 10 years ago, without any cabling or regulator. The regulator cost a further $600.
The advice to have longer cables is good, it is not uncommon to need the extra length when you want to park in the shade & have the panel out in the sun. I have 10 metres for the Patrol, would like to have MT's extra 10m, but because I am using 13mm cable (for 300w portables) 10m is the compromise due to weight. Upgrading to 10m of 8mm cable would be worthwhile for you. Bear in mind that 8mm relates to the cross section of copper in the cable, NOT including the insulation. Many people buy autocable which includes the insulation in the measurement, & has significantly less copper. Eg. 6mm autocable is actually only about 4.6mm copper.
The included regulator will also be worthy of replacing for two reasons. Quality & positioning.

Quality - there is a reason why you can buy this sort of regulator for $10 to $20 but pay several hundred dollars for other regulators. Basically like oils ain't oils, regulators ain't regulators. What you have will 'work' but spending a bit more will get you something that will work more efficiently & treat your battery more kindly. This Morningstar reg would be a huge improvement (Morningstar make good quality gear) http://www.ebay.com.au/itm/Morningstar-ProStar-15A-12-24V-Solar-Controller-Basic-/291116856170?pt=AU_Solar&hash=item43c7eab36a&_uhb=1 or if you wanted to spend less but with a digital readout (useful) this Steca will do a good job for you. http://www.ebay.com.au/itm/SOLAR-CHARGE-CONTROLLER-REGULATOR-15AMP-STECA-SOLAR-POWER-CONVERTER-CHARGER-/281273486416?pt=AU_Solar&hash=item417d34cc50&_uhb=1 At the cost of regulators we are talking about mention of MPPT is no more than a joke. Better to get a good quality PWM reg with temperature compensation.

Positioning. Having a regulator mounted on the back of a solar panel might be convenient for marketing purposes, but it far from desirable as far as charging your battery goes. It will behave according to the voltage it 'sees', which will be quite different at the panel than it will be at the battery, especially if those thin cables are used. We are talking efficiency here, & with the output of a single panel, you want as much of it going into your battery as possible. Therefore it makes sense to have the regulator mounted close to the battery. I would advise you to simply bypass the reg on the back of the panel, instead attaching a short length of cable from the panel's junction box to an anderson plug, & attach to a corresponding anderson plug on the cable you run to the car. You can leave the supplied reg in place, or remove it carefully if you wish.

Posting a diagram would be a good idea to get reassurance I expect.

[megatexture]

FYI links not working cuppa.. Well not for me on safari anyways.

[Drewboyaus]

With a solar regulator, I intend to mount one inside the vehicle, on the cargo barrier I expect. This will top up my second battery, which can only be a max of about 60 odd Ah due to available space, while I am in camp
My question is what happens if I want to use the panels with my battery box if I take the fridge from the car when base camping with the family (the solar input on the ArkPak bypasses the internal charger/regulator)?

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[Cuppa]

FYI links not working cuppa.. Well not for me on safari anyways.

Thanks MT, not sure what i did wrong. Fixed now.

[Cuppa]

With a solar regulator, I intend to mount one inside the vehicle, on the cargo barrier I expect. This will top up my second battery, which can only be a max of about 60 odd Ah due to available space, while I am in camp
My question is what happens if I want to use the panels with my battery box if I take the fridge from the car when base camping with the family (the solar input on the ArkPak bypasses the internal charger/regulator)?



Does this answer your question Drew? Second query down. http://www.arkcorp.com.au/boards/topic/4/arkpak-as-permanent-dual-battery-system

[Drewboyaus]

Thanks Cuppa.
So I'm thinking, given my solar will only be set up at camp (it's not permanent) I'm better off not mounting the regulator in the car but setting it up as a temporary/portable so I can plug it into either the vehicle or the ArkPak.
I'm going to get myself one of those in-car chargers too I think.

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