High Ah Portable Battery options

I would be talking to the twelve volt shop or their local equivalent.

There are so many options that it would be worth running it past a pro.

Andrew,

I can recommend the Home of 12 Volt, based in S.A.
They will ship anywhere in Australia.

The Thumper portable battery system would be ideal for your situation.

Thumper Portable Battery System
Site Link

The 75Ah which I use for camping may be a little light on for your needs, but they also manufacture a 105Ah unit encased in a robust case.
These units are AGM style and in fact contain multiple smaller capacity batteries inside.

Minimum maintenance? Couple the Thumper to an 80 watt solar panel which will put back in a fair amount of what you take out.

No commercial association with the Company, although I have talked to the guys from time to time and they really know their stuff.
The Thumper is the best portable battery system available IMO.

Hi Andrew,

The 'FLYER' could be what you need.

I can send you a data sheet.

Regards Derek.

I would go with 2 batteries that way there is some redundancy if a cell fails. Not all your eggs in 1 basket.

The Army Landrovers that are fitted for radio (FFR) have 2 big 12V batteries on a rack that slides in behind the drivers seat. I'm not sure what sort of transmit/receive cycle they run, but they still need to run the vehicle a few times a day to keep the batteries topped up.
Transmitting will use a lot more power than just receiving, so it is difficult to judge consumption without knowing that too.

I take it that you already have a generator, does it have a 12v charging output, as this may make things easier for you when deployed. You might just need a small transformer to keep the batteries topped up when sitting in the shed between call outs.
2 big 12V batteries should run the radios for most of the day and maybe even some low voltage lighting in the HQ for most of the night and greatly reduce the time you need to run the genny for anyway.

Give these guys a look/ call or E-mail and see what they would advise. They could also help fix you up with low voltage lights to stretch your amps further

12V shop

Rainbow power company

Interesting question Andrew and one, which I suspect, may produce some novel input as the post develops.

>able to be transported around a campsite, on/off boat, in/out vehicle
>by 2 fit people without busting their pooper valves (i would guess
>around 70kg or less).

My 88Ah AGM weighs 32kg and I can carry that OK on my own but I would prefer it had rope handles or a decent carry box – so that may be a point to consider. I think it certainly says you should be looking at multiple batteries which would also give you some redundancy in the event one failed - the remaining battery(s) would provide a last ditch “lifeline”.

>a high usable Ah capacity......infrequent use, 1/month

Got to be AGM. Only need maintenance charge once every (in Qld say) three months and have high capacity and no spill when carried – or dropped!

>max 15A @12v continuous current drain @ maybe 2 hours (though
>expect average to be 5-8A continuous @12 hours)

8 x 12 = 96Ah so two 100Ah AGMs in parallel would do nicely – a discharge to about half the battery capacity will give you decent longevity and a decent amount in hand for those times you need to go below 50%.

>priceWe are looking at setting up a silent 12V system able to be utilised
>to run a Field Search & Rescue Headquarters in remote locations

What are you rescuing?

>We currently run various 240V systems successfully however
>we want to explore the 12v world, therefore we are not looking
>at an Invertor style system thanks

Stay 12V if you can as an inverter only adds a level of inefficiency to the system although it can make some things more convenient. A 12V switch mode mobile phone charger will probably be more efficient than a 240V mobile phone charger run through an inverter fed from a 12V battery – however this is not a God Given and something you should check on your individual appliances.

>Obviously we will need to consider high quality battery chargers
>in the next stages, potentially a battery monitoring and/or
>management system etc.

You will but, as you say, that is a stage two design process – unless you can get satisfactory performance from the 12V system in the first place there is no point in worrying about how to maintain it! :)

>Difficult subject, sorry guys, just want some straight answers and/or ideas.

Not at all – I shall follow the thread with interest.

Mike Harding

mike_harding@fastmail.fm

Start off with a Christies 12V 55A (12kg) generator into a couple of Odyssey 12V batteries 65 A/H (20kg each) hooked up together with appropriate Anderson plugs.

Odyssey shelf life ~3 years or so if left charged (spillproof rated to be safe for aviation carriage - listed as a "dry cell"), Christies gen would charge from flat in www.odysseybatteries.com/batteries.htm

Specifically Site Link "Reserve capacity: 240 minutes on 25amps" should give you enough time to hook everything up and running before worrying too much about recharging. "Deep cycling capability: 400 at 80% DOD", read - 80% depth of discharge compared with 50-60 of other batteries capacity and four hundred times at that.....

Site Link

Further info on Christie's:

Christie Engineering

* Business type: Manufacturer of high powered DC battery chargers
* Product types: DC High current output generators for battery charging, Remote area backup chargers, portable camping chargers, marine chargers, recreational vehicle chargers, Outback Battery Chargers 12 volt-55 amp, 80 amp or 120 amp, 24 volt 45 amp 55 amp or 80 amp. We manufacture petrol or diesel powered chargers to suit your needs..
* Service types: Supplier of remote area battery charging
* Address: 123 Delaware Rd Horsley Park, Sydney, NSW Australia 2164
* Telephone: 02 9620 1208

Andrew, have you asked other S@R orgs what they use ? No need to re invent the wheel.

I won't suggest anything about the batteries except that your $500 budget is a fraction of what you need for a reliable system.

Carting them around interests me - is it worth mounting it all on a two wheel removalist trolley? - you could even let the tyres down when walking over sand :-)))