A great debate! Hubby vs wife

Ok all this is the last time I will request help regarding the electrical system in our car for our big lap of Australia. We have a Rodeo 2007 with a flat tray housing 2 enormous metal boxes one of which will carry the 80L Waeco fridge. We will either use 240v power when in a caravan park at a powered site or 12v when in the bush. We have 2 lights that are 240v and two lights for 12v situations . One is an led and one a fluro. We may run a small 6inch 12v fan in hot areas. I have read all the information readers have pointed me to when I previously asked for advice in this matter and so I duly explained to hubby we need two have 2 120ah AGM batteries, one in the box with the fridge and one in the camper trailer. We do not need an inverter but we needed a multi stage charging system as well as the car charing the batteries whilst we are travelling, an isolation switch to stop the starter battery going flat and a 120w solar panel to top up the batteries on extended bush stays of say a week tops. We have been quoted around 2 and a half thousand, give or take $500. Hubby agrees to get two AGM batteries but wants just to have an anderson plug to the car so the batteries can charge whist driving and a solar panel to top the batteries up that can clip on using aligator clips to the batteries. The total set up is around $1500. Not being totally on top of all the knowledge I cannot get my point across, but then again I may not need to as hubby dare I say it may be right!!!!
Back Expand Un-Read 0 Moderator

Reply By: Member - MUZBRY(Vic) - Tuesday, Jan 31, 2012 at 21:14

Tuesday, Jan 31, 2012 at 21:14
Gday
Either way, no need to have an argument.

Muzbry
Great place to be Mt Blue Rag 27/12/2012

Lifetime Member
My Profile  Send Message

AnswerID: 476524

Follow Up By: Carreen - Tuesday, Jan 31, 2012 at 21:51

Tuesday, Jan 31, 2012 at 21:51
Lol if we were the arguing type I don't think we would last on the road for nine months together. We will both eventually get round to an idea. It's not about who is right but what is going to be the best system so it is easy on the road.
Cheers
0
FollowupID: 751630

Reply By: Hi-ryder - Tuesday, Jan 31, 2012 at 21:15

Tuesday, Jan 31, 2012 at 21:15
Hi Carreen Your car will not charge two 120 amp battery's to their full potential Plus its own battery . The alternator just wont do it . You will have to get a charger of some kind . Solar is alright but you need to be chasing the sun . So really your only really getting 8 hours max out of a solar panel if your chasing the sun . I would buy a cheap inverter just to run phone chargers and camera charges off . Handy little things at times . Good luck with your trip
AnswerID: 476525

Follow Up By: vk1dx - Wednesday, Feb 01, 2012 at 09:03

Wednesday, Feb 01, 2012 at 09:03
Hi Ryder

What about a larger alternator? The son put one in his Datsun rally car when he put an array of lights across the front. They must be around. That would help with charging the batteries whilst driving.

Phil
0
FollowupID: 751662

Follow Up By: TerraFirma - Wednesday, Feb 01, 2012 at 12:22

Wednesday, Feb 01, 2012 at 12:22
The last thing they need is an inverter when they don't know if they will have enough battery power. Also you don't need an inverter to charge phones and cameras, this can be done with 12v, so creating 240v just to do this is inefficient. They need to be able to re-charge 240AH on top of the car battery so access to 240v with a battery charger or some really big solar panels would be required. On the alternator that is worth looking into, every little bit helps.
0
FollowupID: 751675

Follow Up By: Member - MUZBRY(Vic) - Wednesday, Feb 01, 2012 at 20:53

Wednesday, Feb 01, 2012 at 20:53
VK1DX or Phil
A young chap i know has put two alternators on his old Ford to keep the batteries full.

Muzbry
Great place to be Mt Blue Rag 27/12/2012

Lifetime Member
My Profile  Send Message

0
FollowupID: 751727

Follow Up By: vk1dx - Wednesday, Feb 01, 2012 at 21:10

Wednesday, Feb 01, 2012 at 21:10
By the look of the one on the Datto, its off a ford truck. A bloody big one.He has 600 watts of driving lights and another 400 watts of high beam. It's got a fuel injected 2.4 to kick the little 1600 body along.

The standard one was useless. We used to take extra batteries until he found a big one to fit.

Phil


0
FollowupID: 751734

Reply By: Axle - Tuesday, Jan 31, 2012 at 21:22

Tuesday, Jan 31, 2012 at 21:22
G/Day,......Fight You buggers Fight!!,,,,,LOL...It will work out!...Somehow!



Cheers Axle.
AnswerID: 476529

Follow Up By: Carreen - Tuesday, Jan 31, 2012 at 21:51

Tuesday, Jan 31, 2012 at 21:51
Yep I know even if e make modifications along the way!
Thanks.
0
FollowupID: 751631

Reply By: Member - Fred B (NT) - Tuesday, Jan 31, 2012 at 21:54

Tuesday, Jan 31, 2012 at 21:54
Hi Carreen,
a good multi-stage charger would be good for the times you have access to 240V to fully charge those batteries - not the low amperage ones, but say 25amp or more, otherwise it just takes too long to charge them.
regards,
Fred B
VKS 737: Mobile/Selcall 1334

Lifetime Member
My Profile  My Blog  My Position  Send Message

AnswerID: 476533

Follow Up By: Carreen - Tuesday, Jan 31, 2012 at 21:57

Tuesday, Jan 31, 2012 at 21:57
oops does it look like the debate is swaying my way???
Thanks for that info
Carreen
0
FollowupID: 751632

Follow Up By: TerraFirma - Wednesday, Feb 01, 2012 at 12:24

Wednesday, Feb 01, 2012 at 12:24
Definitely need a multi stage charger like a Ctek 25 amp or something similar, Ctek is my preference, can't beat the quality and safety features imo.
0
FollowupID: 751676

Follow Up By: Brian Purdue - Wednesday, Feb 01, 2012 at 13:33

Wednesday, Feb 01, 2012 at 13:33
I do not know how many times I have posted it. The be-all and end-all is BUY A GENERATOR! No mucking around with batteries, no invertors, no voltage regulators no worrying about looking for sunshine, and, if you buy a reputable brand - no worries. The oonly downside is, if you are driving a diesel (sad-face) you need two lots of fuel.
0
FollowupID: 751684

Follow Up By: TerraFirma - Wednesday, Feb 01, 2012 at 15:17

Wednesday, Feb 01, 2012 at 15:17
Brian, That is not the only downside. You forget to mention generators are not allowed in many areas, they are noisy. Otherwise yes they are an essential item permitting.
0
FollowupID: 751696

Follow Up By: Brian Purdue - Wednesday, Feb 01, 2012 at 17:47

Wednesday, Feb 01, 2012 at 17:47
With all due respect in 99% of the cases your comment is invalid. If you are in a caravan park you just plug into the mains. Elsewhere you can stop on the side of the road for lubch and chargeup. I tended (I am now too old and ill to travel) to bush camp. Far from the madding crowd and away from noisy drunks and screaming children. Caravan parks were for the weekly shower and laundry then I left!!
0
FollowupID: 751705

Follow Up By: TerraFirma - Wednesday, Feb 01, 2012 at 20:59

Wednesday, Feb 01, 2012 at 20:59
Not true Brian, there are many camp sites without power that do not permit generators. On top of that many people go camping for the serenity and generators can sometimes spoil that. You might like to Google the subject, very valid old boy..
0
FollowupID: 751731

Follow Up By: Brian Purdue - Wednesday, Feb 01, 2012 at 23:15

Wednesday, Feb 01, 2012 at 23:15
A case of "Do not confuse me with facts. I have made up my mind"?
The post requested opinions. You have yours. I have mine. I would never, ever have travelled without a generator. 1500 units make little noise and are light and practical. I kept one in the back of my Range Rover and found it very handy. If you really want to attend places where there are squillions of people I fail to see why you leave home. AND THAT is my opinion too.
0
FollowupID: 751749

Follow Up By: TerraFirma - Wednesday, Feb 01, 2012 at 23:21

Wednesday, Feb 01, 2012 at 23:21
Gee Brian no need to get wound up. I have 2 x generators . I dont disagree with you, merely pointing out the downsides. Take care..
0
FollowupID: 751750

Reply By: Battery Value Pty Ltd - Tuesday, Jan 31, 2012 at 23:04

Tuesday, Jan 31, 2012 at 23:04
Hello Carreen,

Worst case scenario:

both of you start a war in the middle of nowhere because you're out of battery power ;)
Imagine you're stationary for several days, and it's overcast.
Your fridge and other loads easily consume 80Ah per day, but your solar panel isn't coming up with much solar energy.
Even on sunny days, your solar panel only yields about 30Ah per day, so there's always going to be a shortfall in solar energy.

Both batteries could be depleted within 2 or 3 days.
So what do you do for charging?
Number one: start the motor and let the alternator put some charge into them.
For this to work, the alternator voltage has to be a minimum of 13.8 to 14V.
And the cabling between alternator and batteies needs to be adequate.

Alternator charging alone won't fully charge the batteries, so they'll be sitting at around 80% state of charge after the motor stops.
The alternator has to be run every day, for at least one hour if the sun shines, or 90 minutes if there's no sun. Do this in the morning, when the batteries' charge acceptance is greatest.
You should also carry a voltmeter/multimeter, which is handy for checking the battery voltage for a rough estimate of state of charge.

It's therefore imperative to purchase a quality multistage battery charger with a recommended max charging current of 25~60A, for topping up the batteries when near 240V power.

There are more expensive options, like DC/DC charging, or more solar panels, a generator...but the mains powered battery charger, and a half decent alternator charging arrangement should do the trick for you.

cheers, Peter
AnswerID: 476541

Follow Up By: Wayne David - Wednesday, Feb 01, 2012 at 08:36

Wednesday, Feb 01, 2012 at 08:36
That was a great read Peter.

I know almost zero about such matters but thanks to you I now know a little more.

I'm going to scan this and add it to my collection of information.

Cheers - Wayne
0
FollowupID: 751658

Follow Up By: Carreen - Wednesday, Feb 01, 2012 at 21:50

Wednesday, Feb 01, 2012 at 21:50
Thanks Peter,
The Penny just dropped!! When I said a multi stage charger I thought I was meaning the thing connected to the whole system in the car etc. and not a seperate item you only use on 240v. Otherwise what would be the point of that when you are bush camping with no power for a week! You cannot use it to charge the batteries then if they go flat. So what I meant to say is we need a DC-DC charger. By the way what is a BC-DC charger and what does it do?
Thanks, Carreen
0
FollowupID: 751740

Follow Up By: Battery Value Pty Ltd - Wednesday, Feb 01, 2012 at 22:44

Wednesday, Feb 01, 2012 at 22:44
welcome Carreen,

DC/DC chargers allow a battery connected to them to reach a higher charging end voltage, thus fully charging them in a reasonable amount of time.

Some popular models can reach a charging rate of 20Ah/hr (max charging current of 20A). Some others claim even higher charging rates.

Whether or not they can sustain this current regardless of ambient temperature, is another question, because the voltage conversion process generates heat.
There are internal temperature sensors which signal to the controlling circuitry to reduce the charging current to protect itself from the effects of high operating temperature.

Remember you may need to find a way to put back 80Ah of charge into your batteries on a daily basis (actually a bit more due to battery inefficiency).
So that would mean you'd have to run the motor at least for 4 hours (4hrs x 20A=80Ah) - this is just a rough estimate because there are other factors.

Now compare this with the alternator:
it is capable of delivering charge at the rate of 60Ah/hr (60A current) or even higher.
The only problem with the alternator is that its voltage isn't quite high enough to get the batteries to 100% state of charge within a reasonable amount of time. So the alternator will quickly push the SOC up to a level of around 80% and from there on things will go really slow.
But it doesn't matter if the batteries only get charged to 80% SOC, as long as you top them up once per week, or fortnight by using a proper multistage mains powered charger.

In a nutshell, the alternator gets the batteries to 80% SOC faster than any DC/DC charger, provided the wiring between alternator and batteries is adequate.
And the battery capacity needs to be sufficiently high as well, in order for them not to be overwhelmed by the high charging current - but your proposed 2x120Ah batteries are good for a charging rate of 60Ah/hr no probs.

One major drawback of DC/DC chargers is that they tend to over-charge the batteries because they generally have difficulties handling the absorption/float switch-over well enough.
A dedicated multistage mains powered charger is easier to use because you can actually observe what's going on by simply connecting a multimeter across your battery during charging, and intervene if necessary (not easily done with a DC/DC charger while cruising).
The above is even more valid for concurrent loads like fridges which can confuse the charger quite easily.

May I suggest again to do the following:
check the alternator voltage if it's in the range between 13.8~14.0V (multimeter across starting battery, motor on fast idle).
Ensure this voltage is actually kept up by checking again after 15 minutes, don't turn off the motor during this 15 minutes wait.
If ok, get a good sized pair of wires like #6 for the connection between starting battery and house batteries. There should be a 80A rated fuse at both ends of the wire connecting the two batteries' positive terminals.

And buy a good robust battery charger, and a pair of 125Ah quality deep cycle AGM batteries - preferably from one and the same dealer who happens to know his stuff. Stops the blame game in the unlikely case something goes wrong.

regards, Peter
0
FollowupID: 751748

Reply By: Motherhen - Wednesday, Feb 01, 2012 at 00:12

Wednesday, Feb 01, 2012 at 00:12
The fridge IN a metal box Carreen? What about air flow and ventilation?

We sometimes run an Engel under the bed as a freezer or back up fridge; under the bed is a huge cargo area. When we stop we lift the bed, and if hot, open the cargo door when the bed is down (like when we're in it).

I would prefer to have a fridge out in the open air.

Mh
Motherhen

Red desert dreaming

Lifetime Member
My Profile  My Blog  Send Message

AnswerID: 476547

Follow Up By: Carreen - Wednesday, Feb 01, 2012 at 21:52

Wednesday, Feb 01, 2012 at 21:52
Hi Mother Hen,
Isn't a car just a bigger metal box? A lot of fridges are housed in boxes on the camper trailer draw bars aren't they? I will check it out-thanks
Carreen
0
FollowupID: 751741

Reply By: Member - John and Val - Wednesday, Feb 01, 2012 at 10:17

Wednesday, Feb 01, 2012 at 10:17
Hi Carreen,

Not too sure just what the argument's about! I think you are both right, but in your own ways, and the price difference reflects those different approaches, plus different profit margins!

A suggestion - The fridge is the big consumer. The power required for the lights and maybe a fan is pretty close to negligible in the overall scheme. I would install both two batteries with the fridge and draw what little power you need at the trailer through an Anderson Plug connection from those fridge batteries. (Not convenient if you want to separate the trailer from the vehicle, but puts your storage where 90+% is actually needed, and allows good use of a 12V-12V charger if the alternator voltage is too low.)

Costs (ballpark)

VSR to connect/disconnect alternator charging $80
120W Solar panel $250 to $400
MPPT solar controller $100
2 x batteries $400 to $500
240V battery charger $160 to $200
12V to 12V charger $200 to $250

Total up to about $1500

Add freight and instal costs.


There was a good post here in the last week or so re reputable ebay suppliers of cheap solar panels. For a controller I wouldn't go past the one from Battery Value for value for money. Their batteries too are very good value, though being Brisbane based, freight may be a killer.

Depending on alternator voltage, the 12V to 12V charger may not be required, but $250 will buy you a 30 amp ABR Sidewinder one which would be ideal if the 2 batteries are installed close together. (Their VSR is also good value.) I mention Battery Value and ABR Sidewinder as they are both businesses that are are EO members and valued contributors here.

All up, including the chargers, freight and installation, I can see $2000, but not much more for a good full system.

Cheers

John

J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein

Lifetime Member
My Profile  My Blog  Send Message

AnswerID: 476564

Follow Up By: Carreen - Wednesday, Feb 01, 2012 at 21:55

Wednesday, Feb 01, 2012 at 21:55
Hi John,
I get your point but we will be disconnecting the car a bit and in some places we may travel without the car such as up to the Mitchell Plateau. Thanks for the information.
Carreen
0
FollowupID: 751743

Follow Up By: Member - John and Val - Thursday, Feb 02, 2012 at 08:21

Thursday, Feb 02, 2012 at 08:21
Hi Carreen,

Yes, there is a downside! BTW, it's a long hot walk to the Mitchell Plateau without the car!!!!!

Cheers, and have a great trip.

John
J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 751760

Sponsored Links

Popular Products (13)