Which Battery/Battery Box combo

[SimpleSi Member Find all posts View Profile Close SimpleSi]

Hi all,
Planning on camping on Moreton Island later this year, and up to Carnarvon Gorge next (5 days each), so I have a requirement to buy a battery to run the 47L ARB fridge, some LED lights and charge the odd gadget (Phone/UHF's). I don't particularly want a 2nd battery in the 150 GXL due cost and weight, so I'm looking at putting a deep cycle battery in a box.
Wondering if anyone could recommend a battery/box combo.

Some factors:
- AGM batteries seem like the way to go. I plan to buy a smart charger ($100ish?) and keep the battery connected whenever not in use.
- I have a 120W folding solar panel, this one I think: http://tinyurl.com/p294cv7 So I suspect I could probably get away with a 100aH battery?
- Arkpac/Engel boxes at $400 are not an option (Can't see the value)
- Thinking this might be an option: http://tinyurl.com/ko7ggat but has anyone heard of "Powersonic" batteries? He also sells an "SSB" 130aH battery with the Projecta box for $340.

Any help/tips appreciated.

[r4ndll Avid PP Poster! Find all posts View Profile Close r4ndll]

By pure chance I am selling a 2 year old combo. Check out the for sale thread: http://www.pradopoint.com/showthread...861#post486861

[SimpleSi Member Find all posts View Profile Close SimpleSi]

Don't know that I'd ever buy a 2nd hand battery, but thanks!

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

I have an ABR battery box with a 105? amp gel battery. Has worked fine for 4 years. Quick and easy to remove so you are not lugging 35 kg around for the 99% of the time you don't need it.

[Symo Advanced Member Find all posts View Profile Close Symo]

+1 the ABR Sidewinder battery box, had mine for 4 years now and it houses a 120AH battery, or you can get a kit from them that houses 8x15AH batteries which is superior and faster to charge.

The box was installed on the boot of my GU Patrol, then in the trailer, now in the shed. I throw it in the trailer when I go camping, runs the lights and recharges gadgets, and will run a small fridge for a week no worries.

I ran an 80L engel for 5 days at Fraser in september bandit was at 11.8v which is not bad.
I keep it recharged with a Projecta 6-stage charger and while they are $150 at super cheap you can get them off eBay from a 4WD shop in VIC for $70 delivered.

I now have a Optima D34 in the 150, and take the battery box for the long trips.

[MelbournePark Member Find all posts View Profile Close MelbournePark]

Symo - I am surprised you got 5 days from your 120 AH. If you run the battery down to 10.5 volts, your battery will not last nearly as long. Down to 10.5 volts would be whole 120 AH.

5 full days at Fraser - should I say four because the fridge was running off the car going to the camp etc and the fridge was full of cold stuff when you arrived at Fraser? its 80 litres so lots of cold stuff when you arrived, that stuff would keep the load off the fridge until the next day (the night load might not have been great too). People say fill the spare space with drinks for your trip to you site as the liquid keeps the fridge cool for quite a while.

So let me say 4 days of battery work for your fridge?

A fridge like yours would be using (depends on the temperature) at least 3 amps draw while operating. The issue is though that they cycle in and out. When the compressor kicks in, the draw is more like 8 or 9 amps I have read ... which puts up the average draw to 5 amps. Then one has to work out the "duty cycle" ie how much time its running for. How much time did your fridge run off the motor (ie while touring around the island)? Lets say 8 hours? That lowers the load by a third of a day. So, the days' load is now is 3.67 days.

So all up hours fridge use would be 24 hours x 3.67 days = 88 hours all up. 120 AH / 88 hours = 1.36 A available per your usage hour.

If the fridge does use 5 Amps when its running, and there was 1.36 A available (which we worked out above), then the "duty cycle" of the fridge must have been 1.36/5 A = 27%; 27% x 24 hours means the fridge compressor was running for 6.5 hours a day. Does that sound about right?

If it was hotter, then you may have lost the fridge ...

But for what you have been doing, your certainly running the world's cheapest setup, and great for long weekends or obviously September Fraser Islands. You're a damn cheapskate. Damn it - a clever one too ...

[MelbournePark Member Find all posts View Profile Close MelbournePark]

What is interesting is that low cost solar ebay kit that Simon bought. http://tinyurl.com/p294cv7

My understanding is that a 12V solar setup runs at 17- 18 Volts, and that for charging, it needs to be regulated down to the battery voltage. There are two methods for doing that, one which basically turns on and off the solar cell to lower the voltage going out (hence its not as efficient) which is the PWM way (Pulse Width Modulated). The claimed 30% more efficient way is MPPT (Maximum Power Point Tracking), which tracks the battery and adjusts the voltage according to the battery’s needs. However I’ve read that MPPT uses a lot of power itself so until 1,000 volt systems it’s no more efficient than the turn off/on switching PWM method.

Simon’s solar kit has a battery output and also is MPPT. I wonder - can it handle directly charging the battery while the battery is running the fridge?

I looked at the panel advertisement and could not see a battery matching switch. I presume you can select the battery type ie AGM or I guess flooded? Even Gel?

There is another concern, and that it may not have a battery temperature sensor. I’ve read that if you charge a battery while drawing from it, the battery can overheat and you damage the battery. A charger with a temperature sensor avoids that. But perhaps the somewhat slight draw of 9 amps now and then and 3 amps lots of the time, is not going to overheat things while power is being added. From what I’ve read if you running two fridges then that battery overheating issue is more likely.

But anyway, how much can the solar contribute, and how to get it into the battery?

If its hot weather, 120W ÷ 12V = 10Amps. OK then you have various other issues that reduce the power, so lets say you get 75% output on a hot day for 2 hours, and 6 hours at 30%. 7.5 x 2 = 15 AH plus 6 x 3 = 18 AH = 32 AH benefit. I guess if its not stinking hot then you might get a lot less than that – perhaps half? Experienced users might comment on their real outputs? If it plugs straight into the battery box setup then it will greatly extend the battery life and it sounds a cheap way of doing things.


Now if that solar power is plugged into a DC : DC charger – but first – the DC : DC would need to have an un-regulated solar input to accept that solar panels regulated power. Because I’ve read that a regulated DC : DC solar input will not accept regulated solar power. There’s a need to check with the seller to buy the rightDC : DC unit for your solar setup IMO.

Anyway – how much power benefit here from the solar to the battery? If the fridge is running full bore as a freezer at 5 AH for 8 hours you'd drain 40 AH. But add back 32 from the solar and you’d extend the battery life power a lot.

I guess the fridge would duty cycle at 40% more typically, hence the drain would be a lot less ie 2 AH (40% of 5 AH) for 8 hours, a drain of 16 AH. Hence a gain from the solar is possible of 16 AH from the daytime usage. But in Victoria, maybe you’d break even, as you might get half that solar output.

Worth doing for the low price of solar these days. The night fridge usage would continue to drain the battery though. But solar now seems very worthwhile.

[r4ndll Avid PP Poster! Find all posts View Profile Close r4ndll]

Don't know that I'd ever buy a 2nd hand battery, but thanks!

Go on! It's a very good battery. It's only been used once

Nah, it's understandable . If I don't get any interest I'll keep it as I'm looking at getting a trailer next year. I'll probably chuck it in there

[Guest Close Guest]

If its hot weather, 120W ÷ 12V = 10Amps. OK then you have various other issues that reduce the power, so lets say you get 75% output on a hot day for 2 hours, and 6 hours at 30%. 7.5 x 2 = 15 AH plus 6 x 3 = 18 AH = 32 AH benefit. I guess if its not stinking hot then you might get a lot less than that – perhaps half? Experienced users might comment on their real outputs? If it plugs straight into the battery box setup then it will greatly extend the battery life and it sounds a cheap way of doing things.

A solar panel's efficiency is reduced the hotter it is. The solar panel's output wattage is based on the cell temp of 25degC. When placed in the sun, the cell temp can be anywhere upwards of +15degC above ambient temp. Therefore, the hotter it is, the less generation you will get from solar panels.

[MelbournePark Member Find all posts View Profile Close MelbournePark]

A solar panel's efficiency is reduced the hotter it is. The solar panel's output wattage is based on the cell temp of 25degC. When placed in the sun, the cell temp can be anywhere upwards of +15degC above ambient temp. Therefore, the hotter it is, the less generation you will get from solar panels.

And that also depends on the sensitivity to heat. My father heated out swimming pool in 1963, with plastic pipes on top of polyethylene sheeting on the flat garage roof in Melbourne. If you put a layer underneath a solar cell of pipes, and put water through it ... I reckon you could not only recover some energy, but would increase the panel efficiency. If you were outputting the panel's voltage.

And also, the panel's losses depend also on their type, and their losses due to heat, which all vary.

But for charging 12v batteries - what you say may not often apply. Because the panels are 18v panels - and they have to shed volts to charge a 12 volt battery. They'll be shed down from 17-18V to - for a battery charger - typically between 13.8 to 14.5. That means you've don't loose straight away. While temperatures increase, the panel voltage decreases, but the battery charge is not effected.

But anyway - What's your constructive advice?

As far as panels go, daylight, cloud and shade are the big issues, and geographical position is less of an issue, but its still important. For a high voltage systems, heat voltage losses must be much more critical.

[AK7 Senior Member Find all posts View Profile Close AK7]

I did have my eye on the Arkpak but have been advised that I'd do better making a similar thing myself. A couple of 12V outlets and a couple of USB outlets. Disregard the 240V inverter (I would have gone 600W). One of my concerns was charging and maintaining it, but I'm starting to think I'm better off just popping a home-made battery box on a decent 12V charger at home once in a while rather than dicking about leaving an Arkpak plugged in whenever I'm not using it... Any comments on that?

[Symo Advanced Member Find all posts View Profile Close Symo]

Which Battery/Battery Box combo

Symo - I am surprised you got 5 days from your 120 AH. If you run the battery down to 10.5 volts, your battery will not last nearly as long. Down to 10.5 volts would be whole 120 AH.

5 full days at Fraser - should I say four because the fridge was running off the car going to the camp etc and the fridge was full of cold stuff when you arrived at Fraser? its 80 litres so lots of cold stuff when you arrived, that stuff would keep the load off the fridge until the next day (the night load might not have been great too). People say fill the spare space with drinks for your trip to you site as the liquid keeps the fridge cool for quite a while.

So let me say 4 days of battery work for your fridge?

A fridge like yours would be using (depends on the temperature) at least 3 amps draw while operating. The issue is though that they cycle in and out. When the compressor kicks in, the draw is more like 8 or 9 amps I have read ... which puts up the average draw to 5 amps. Then one has to work out the "duty cycle" ie how much time its running for. How much time did your fridge run off the motor (ie while touring around the island)? Lets say 8 hours? That lowers the load by a third of a day. So, the days' load is now is 3.67 days.

So all up hours fridge use would be 24 hours x 3.67 days = 88 hours all up. 120 AH / 88 hours = 1.36 A available per your usage hour.

If the fridge does use 5 Amps when its running, and there was 1.36 A available (which we worked out above), then the "duty cycle" of the fridge must have been 1.36/5 A = 27%; 27% x 24 hours means the fridge compressor was running for 6.5 hours a day. Does that sound about right?

If it was hotter, then you may have lost the fridge ...

But for what you have been doing, your certainly running the world's cheapest setup, and great for long weekends or obviously September Fraser Islands. You're a damn cheapskate. Damn it - a clever one too ...

Use it lose it I say, it's a consumable. I only get away once or twice a year and it's already four years old and as good as new.

Draining it hard won't break it overnight, it takes a 200 or so cycles, and at the rate I do it it would last longer than me, we all know if you looked after it it would wear out in 5-10 years so there are bigger issues at play, and warm beer isn't one of them.

My waeco uses 0.7amps an hour on average, so do the math, my brother engle is double that, again do the math. I use all 120amps if the are there, I paid for 'em might as well use them.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I made my own. Plastic battery box, 120AH Ritar battery. An Anderson plug for the fridge, two 12V sockets and a BCDC1225 on top with a grey Anderson plug input from the engine and a red one for solar input. Easy to wire up yourself and it gets used in/on the back of two different Utes.

[SimpleSi Member Find all posts View Profile Close SimpleSi]

Easy to wire up yourself and it gets used in/on the back of two different Utes.

I have wondered that. Battery World have pretty basic boxes. Is it a simple job of going to Jaycar and buying usb/12V cig sockets, cutting a corresponding hole the box, and connect red to red, black to black? (I can't solder for sh!t)

[Guest Close Guest]

I have wondered that. Battery World have pretty basic boxes. Is it a simple job of going to Jaycar and buying usb/12V cig sockets, cutting a corresponding hole the box, and connect red to red, black to black? (I can't solder for sh!t)

You will need crimps and crimping tool. Also heatshrink and heat gun. Plus fuse(s).