Battery jumpstart units to run Waeco fridge

briche · Guru

Battery jumpstart units to run Waeco fridge

Nichol · Member

Hi Briche,

The issue with the portable jump start units is that they are designed primarily to start your car. As with a car battery they supply a large current for a short time, but overall do not need to supply a large amount of power.

When talking about a fridge you are looking at consumption anywhere between 2 amps an hour to 6 or higher amps an hour, depending on the size of the fridge, efficiently of the fridge, ambient temperate etc.

What you need to do is look at the amp hour capacity of the battery. This is measured in amp hours or a/h. Beware of CCA or cold cranking amp rates. This has nothing to do with the total power the battery hold, but is a measure of how fast a battery can provide power, important for starting cars. In the jump start packs the battery hold 30a/h or lower of power) and then work out the amount of power that you will draw. If your fridge uses 4 amps an hour of power and the starter pack is only 30ah (effectively 15ah as you should only run these batteries down to 50%) you will get around 4 hours of run time on your battery.

160 watts of solar will provide you with approximately 35 amps of power per day back into your system. (this is an average. Higher in summer with long sunny days)

This basically means that depending on the power consumption of your fridge you may not have enough solar to keep the fridge running indefinitely and will need a fully charge battery to start with to prolong the time the fridge will run.

Depending on the size of your battery especially with the small ones in jump start units you will find that it runs flat pretty quickly, especially once the sun goes down and there is no assistance from the solar.

If you are after some information about understanding the consumption relating to batteries there is a bit here

http://www.touringtechnology.com.au/power/information/whatsawatt.html

Cheers,
Nichol

Duckster · Veteran Member

depending on the size of your fridge use minimum 80Ah deep cycle battery. Suggest use Ctek D250S Dual to charge the battery correctly when travelling. The D250S Dual $275 is also MPPT solar regulator. D250S Dual only requires 2 wires onto start battery and 2 wires onto fridge battery. http://www.ctek.com/int/en/chargers/D250S%20DUAL

jimricho · Guru

I have used my 1900 amp jumpstarter to run my Bushman and can get a day's running out of it in normal ambient conditions. In hot weather this would be less and in cool conditions more. The Bushman was not set for deep freezing but normal refrigeration just above freezing.

I only use this as a backup as the aux battery (Optima Red Top) in the Pajero is about 50 ah and this is limited by the space available in the engine bay. If I had the space I would have installed a 100ah AGM, probably the most commonly used size for an aux battery.

(1900 amps is an arrant piece of fiction that they use to rate the jump starter. It wouldn't deliver anything like that when starting a car.)

PS: I haven't used the M205 suggested by Duckster but I have had many years of trouble free use out of other Ctek products.

-- Edited by jimricho on Thursday 1st of December 2011 07:21:24 AM

briche · Guru

Thank you all for your reply's. The answers I got were as expected but I just needed to ask. I was not very familiar with these jumpstart units but all your comments just confirmed what I thought in the first place. Once again, thank you. Brian

milo · Guru

i looked at one of these yesturday, to run my laptop, light , and they said i can connect
to the caravan park power with the normal 15amp leads..
http://jaycar.com.au/productView.asp?ID=MB3594&CATID=83&form=CAT2&SUBCATID=998#3

i hope this will be alright..or something similar

Nichol · Member

Milo,

This init only has an 18ah battery in it.

If it is a led light you use and you do not use your laptop too much it should be ok.

It is easy as they come ready with all the chargers etc, however the chargers they come with are usally very slow as these systems are designed to stay on standby and be used to jump start when needed.

Cheers,

Nichol

Duckster · Veteran Member

Milo think you would call it junk "The 400W inverter gives you a 240VAC mains style outlet at the rear for plugging in to charge your laptop or other devices. Powered by an internal 12V 18Ah SLA battery." 400W inverter would be square wave. 10W on 240VAC is 1A on 12V so you can see the 18Ah battery is next to useless. Specs are fantasy

milo · Guru

oh well, was worth a try..

jimricho · Guru

Duckster wrote:
Milo think you would call it junk "The 400W inverter gives you a 240VAC mains style outlet at the rear for plugging in to charge your laptop or other devices. Powered by an internal 12V 18Ah SLA battery." 400W inverter would be square wave. 10W on 240VAC is 1A on 12V so you can see the 18Ah battery is next to useless. Specs are fantasy

My 1900 amp (boy! is that spec ever a fantasy!) is rated at 30 amphours (discharge rate not quoted). I have found this to be realistic when tested with my Bushman.

I still maintain that the best (and least expensive) option for recharging a laptop from 12v is to use a 12v laptop charger/power supply. A suitable unit is available from Jaycar for (I think) about $60. I have and use one of these. A short while back a member of this forum did a like with like test using one of these and a PSW inverter. As I recall the inverter used 60% more current to achieve the same result.

In answering Milo's posts it's best to keep it simple and straight forward as I think he would have difficulty getting his head around sine waves, square waves, amps, volts, watts, ohms, etc. I say this with no disrespect for Milo whatever.

milo · Guru

thanks jim, all i want is a simple easy answer..
i want to have the best of both worlds, power when at a caravan park
and also to be able to stay a day or 2 with out caravan park ,if there are no spots
also maybe a small fridge /cooler
cooler
http://www.bcf.com.au/online-store/products/Waeco-3-Way-Cooler-35-Litre-CA-35.aspx?pid=121620#Description
if that above runs on gas, is a gas bottle ok in the car all the time while travelling?

jimricho · Guru

There are regulations for carrying small gas cylinders in a car but I'm not familiar with them so it's best to check, maybe someone on the forum can help. If it is ok you would need to disconnect the cylinder from its hose to the cooler whenever it's in the car. To use it on gas you would need to lift it out of the car and use it at your campsite. Under no circumstances run it on gas inside a tent or van. It would also need to be level to operate properly.

In short I don't think this would be a very practical solution.

If in a caravan park, camp kitchens usually provide refrigeration storage. You place your stuff in a basket (usually provided) with your name and the date on it so it is identified from other people's stuff.

Waeco also do a range of thermoelectric coolers and although not as efficient as a proper fridge this may be the best option in your case. Don't go for any of the real cheap ones however.

Check out http://www.waeco.com.au/products5.asp?id=205&catId=57&subCatId=58&subCatId2=64

The downside is you need to connect it to you car via a cig lighter, ok for travelling, or to the 240 mains through a suitable power supply box that Waeco supply separately as an extra. A jump starter would be flattened after a few hours.

Unfortunately for free camping it's back to a good ol'fashion esky and ice.