Dual Battery System

Submitted: Monday, May 11, 2009 at 19:53

ThreadID: 68734 Views:3974 Replies:4 FollowUps:2

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Battery Power

In this article we explain why you might need an additional power source independent of the starting battery installed into your vehicle and we look in detail at types of batteries,

Member - Magic (VIC)

Dear All,

Apologies in advance for the lack of technical knowledge for this post, but I will do my best.

We have just upgraded our second fridge from an Aldi 3-way to an Evakool 47L compressor fridge, which we would like to keep in the back of the vehicle and run from a second battery. We have a lead acid 80AmpHr battery in the CT which we use for lights, water pump, the occasional DVD for our son etc. Our CT fridge
is a 3-way, which we run on gas except while travelling. We have an 80watt solar panel which we connect to the camper battery via a Plasmatronics PL20 regulator when we need to top up the camper batter.

Our questions are:

Is it sufficient to just take the car for a trip every few days to re-charge the second battery? If so, how long a trip are we talking about?

If not, could we connect the solar panel to the second battery? We would, I assume need to use a second regulator of some sort.

Because we have a lead acid battery in the CT and one for starting the vehicle, is it best to use an additional lead acid battery, or can we incorporate a deep cycle battery into the mix?

I think that's everything.

Thanks in advance for your replies.

Cheers

Jeannie

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Reply By: Sand Man (SA) - Monday, May 11, 2009 at 20:13

Monday, May 11, 2009 at 20:13

Jeannie,

Looking at what you use your camper trailer battery for, you could simply connect your EvaKool fridge to a second battery and use the solar panel to maintain a charge in it while camping.

Two things you should take into consideration.
The second battery for your vehicle should be an AGM battery for both safety (won't spill and won't create dangerous gases while charging) and will charge quicker and more completely than a wet cell battery. If this battery is contained in a battery case with outlet sockets and a battery monitor, you will have a completely portable system.

You can purchase an ABR Flyer from ABR - Sidewinder but you must buy a suitable battery to place in it.
The most suitable battery is an AGM deep cycle battery of 80 Amp Hour capacity or larger.

There are also devices to enable the power pack to be charged via the vehicle alternator while travelling and you can leave the fridge connected as well.
Your existing solar panel will be quite acceptable to connect to this power pack while stationary at the camp site.

Bill.

Bill

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Follow Up By: Sand Man (SA) - Monday, May 11, 2009 at 20:16

Monday, May 11, 2009 at 20:16

Jeannie,

For a more complete information, have a look at this article from the ExplorOz site.

Vehicle Electrics

It is written by Derek Bester from ABR.

Bill

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Reply By: Best Off Road - Monday, May 11, 2009 at 20:20

Monday, May 11, 2009 at 20:20

Jeaniie,

Pop in and I'll take you through it all. Just give me a call to set a time, we're flat out.

It's all very easy to do, Doug's handy, with a little basic advice you can save yourselves some dough.

Kind Regards,

Jim.

AnswerID: 364374

Follow Up By: Member - Magic (VIC) - Tuesday, May 12, 2009 at 08:55

Tuesday, May 12, 2009 at 08:55

Hi Jim,

Thanks very much for the offer. That would be great. We'll give you a call soon to arrange a time.

Cheers

J.

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Reply By: Peter McG (Member, Melbourne) - Monday, May 11, 2009 at 21:46

Monday, May 11, 2009 at 21:46

Hi jeannie

We also have an Ultimate as do several other EO members. It will definately be worth getting a second battery in the Mazda.
You can the run the Evakool for 2+ days and use the 80w panel to keep it topped up for about another couple of days before running the car.
The camper battwry shouild be good for much longer than this if its charging ok from the car.
As others have said, use AGM batteries if you can afford to.

Cheers

Peter

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AnswerID: 364393

Reply By: Maîneÿ . . .- Tuesday, May 12, 2009 at 10:03

Tuesday, May 12, 2009 at 10:03

Jeannie,
You say: "We have a lead acid 80 ah battery in the CT for lights, water pump, the occasional DVD.
With an 80watt solar panel connected to the camper battery via a Plasmatronics PL20 regulator when needed to top up the camper battery"
The above combination is a small current draw
when compared to the new fridge !!

Why not consider:
Put a 100+ ah AGM battery into the vehicle in a $20 battery box.
(the Plasmatronics will tell you EVERYTHING you will ever need to know about your battery condition and the Solar charging information, and you don't have to pay again for what you already have)

Connect the Solar panel AND Plasmatronics regulator to the AGM battery in the vehicle and use as the PRIMARY battery and charging source, with the ability of connecting back to the 'original' 80 ah battery when you wish to (with an Anderson plug connector)

Just my own thought on a simple matter, as I believe you have to have the Fridge in the primary charging circuit, if you can't turn on a tap because your camper battery is low just connect the camper to the vehicle and run the engine for just 2 minutes then swap over the Solar connector.

Mainey . . .

AnswerID: 364439