Amps are doing me in!!!

To work this out one would need to know the power rating of the lights involved and the amphour capacity of the jump starter batteries. The figures you have given are useless for calculating what you want to know.

When you say the jump starters are 600amp this only refers to the maximum rated cold cranking current delivery and not the amphour capacity.


Try to find out the rated amphour capacity of the batteries and the wattage of the lights.
Divide the wattage of the lights by 12. This gives power divided by voltage equals current.

Then divide the amphour rating of the batteries by this current figure. This gives amphours divided by amps equals hours (approximately).

You shouldn't run your batteries down by more than 50% (rule of thumb) so halve the figure above.

This will give you a rough idea of how many hours you can run your lights.

How many and what type of lights do you use? What is the current draw?

The 950 amp unit I have has a 17 Amp Hour battery in it - my 1250 amp unit has a 24 Amp hour battery in it. So a 600 amp unit will have about 12 amp hour battery in it.

Divide the wattage of the lights by 12 to get the amps it uses. To work out how long it will last (in theory) divide the amp hours of the battery by the amps used. This will give the duration in hours - as batteries do not go right down reduce the duration by about 1/3 to get realistic duration - but a light load might go for the full time, heavier load much less.

Eg - 600 amp unit (12Ah Battery)

Lights are 12w so 12w/12 gives a 1 amp draw - so for for every hour the lights are on 1ah is drawn from the battery.

As the battery is 12ah your max theoretical time is 12hours - but realistically it will be about 9 hours. (however your power pack red light will come on telling you to recharge before this)

Clear as mud - if you are not going to go for a separate battery system I would go for the largest portable system you can get.

Garry

Hi Aidan
I am no expert in this field by a long shut, but here is what you should get basicly.

A good quality camp light, eg Versa Light claim a draw rate of less than 1amp per hour. Working on that theory with a 20 % reserve power in one battery pack, you should have around 500 hours or 20 days at 24 hours a day full time running. As you can see these figures well exceed your weekend trips away, giving you nearly 3 weeks of continuous use before the need to recharge you battery pack.

Cheers

Stephen

Wow! where do I get one of those .
It would run my fridge for for about 2 weeks on one charge.
I have always wondered why I bother carrying around that 30 KG second battery which only lasts 2 days.
Regards Philip A

Hi Aidan,

As you can see, this is a minefield for the young and inexperienced!

My advice is that you would be better off buying a couple of self-contained LED or Fluro camping lanterns. Either re-chargeable or replaceable dry-cells. There are literally dozens to choose from at any camping store, BCF etc.

Having a built-in battery allows more mobility without cables to a separate battery or to the vehicle.

The re-chargeable types usually come with cords to recharge from either 230vac or 12vdc.

Just something else to think about , the jumper packs are designed to supply a high amp output in a few seconds not the opposite ,low amps over a long time. BUT the 12ah battery should last about 7 hours with the 1 amp light, not going to do the battery any good though. The LED lights are a good idea. Why not run your 1 amp light off the car battery, It would recharge the next day.

I would suggest you will be wasting your money getting jump starter packs for powering camp lights. You would be better off getting a good dual battery installation in your vehicle. Use a deep cycle battery in this for best operation and longer life.

Most of the replies above are correct. You don't get much out of those expensive jump packs. If they are not expensive then you will get less out of them.

PeterD

Hi Aidan,

We did just what you are suggesting on our recent trip, using a 12V LED lamp off a 600A jumpstarter pack, just for the portability. Our LED lamp has 30 small LEDs, and this provides enough light on a card table to see what you're doing, but not much more. This system lasted a week with 2-3 hrs per night use, before needing recharging. If you wanted to run more or brighter lights though, you would get less time. (Yes the battery is 12 A hr, so 1A for 12 hrs, etc, though as noted above you wouldn't flatten the battery, so more like 6 A hr actual use).

Cheers, John

just noticed recently the ozcharge jumppack have a 1500amp(3SEC) capability with a vrsla 38 amp hour battery in them for 160 smackas.
if its as good as their chargers its worth it.

I'd guess the 600cca jumppack may only have a 7Ah SLA battery, which is what I've been using for years to power a fluoro. My experience is that you'll get about 7 hours, or about 3 nights worth of useful lighting before you need recharging. (after dinner, we turn the light off and use the stars)..

Hi i have been reading Hobo site as it gives heaps of details about this subject .try putting in Hobo in google and read his many articles from solar power to 12 volt power as he has been traveling Australia full time in his bus for over 7 years

Thanks to everyone who replied to this thread. We've decided to actually have the electrics added to the trailer (we're having a new Cavalier built). Should give us all of the power we need. Big leap from a $30 jump starter to a factory fitted power pack and sockets, but it gives us more options.

Thanks again