Investigator looking for Info please.

Well I might be able to help you seeings as I am an avid camper/4wder who has set up my own dual battery setup and I used to be a PI! LOL

I used to run a 450w Puresinewave inverter. That will easily run your laptop power and video camera supply/chargers. You could even go less that that, but it's always nice to have the option to run other gear!

There are 3 types of inverter:
1. Square wave
2. Modified sine wave
3. Pure sinewave.

My recomendation is for the Pure, however the others would still work, they just would not be as efficiant running all those switch mode powersupples (cameras and lappy etc and could potentially damage them long term).

The CCTV cameras will run straight of the 12v battery, probally just install some extra lighter plugs or other form of 12v plug and make some leads up so you can just plug the cameras in as needed.

It's hard to say exactly how much juice you'll need (battery size) as I don't know the exact draw of your lappy and chargers etc, however I'm guessing that the lappy will draw about 4 amps (a fiar amount, bout the same as an engel going flat out without cycling on and off), the inverter will draw possibly 2 amps just at idle (wasted power, but you can't do much about it) and the video chargers and CCTV will be fairly minimal, maybe 3 amps all together.

So you really are looking at a lot of power being drawn, the only advantage is 10 hours is not like a 48 hour weekend by the river so it should be doable.

So basically we are talking drawing approximatly 9 amps non stop, it'll hurt the battery but if you get one big enough, or maybe run two batteries (plus the normal car battery for starting) you will be right.

This is what I think you will need:

1. At LEAST a 100amp hour deep cycle battery, agricultral shops often sell these batteries alot cheaper than 4wd shops or battery suppliers ( a lot of battery supplies - battery world etc - are rip off's).

You will need to either mount the battery under the bonnet on a battery tray or in the back of the vehicle in a securly mounted plastic battery box (about $20 from superchepa auto for the box).

You will need a minimum of 8g wire (the stuff that they use to run big car stereo amps) or even better 4g (the stuff that runs from your starter motor/alternator to you battery, the big thick stuff) to join the battery to your normal car battery. Between the two batteries I would probably suggest buying a Redarc battery solinoid, they are fully automatic and just switch the second battery off from the main battey when the car is turned off so that you don't flattern you normal car battery, when the car starts it joines them back together and it charges from the alternator as per normal. RedArc's are normally around the $100 mark, you can even buy them off ebay easy enough.

When fitting the plugs and inverter use a thicker cable as is possible, this will reduce the "voltage drop" and allow your battery to last longer, and you gear to run better. With the inverter, I would probably use the same size cable as you run between your batteries, that is, a minimum of 8g as 450w @ 12v is 40 odd amps ( a hell of a lot).

Just a not, just because a cable says it is rated for XXX amount of amps, does not mean it is good to use it for that amount. Typically the rating on wire is the maxium you can draw through it before it melts and catches your car on fire. Ie 20amp cable should not have 20amps running through it for 10 hours, it will cause a severe drop in voltage, making you gear draw way more than it needs to and will probably get awful hot. ie Just use the biggest cable you can.

That's all I can think of for now, hope it helps!

Hi Jeff!
Good to chat to another PI!
Do you still dabble in the game?

Thanks mate, that really clears that up well.
Now why couldnt the local autosparky explain it a simple as that!

I am pretty lucky with my vehicle, the factory battery is under the parcel shelf behind the back seat, there is plenty of room for a second battery and probably the inverter too.
Does the inverter need to be cooled?
How handy are you with a pen?
would you be kind enough to show me how it all fits together?
Now i understand the theory, i think i could join the dots to build it myself.
Instructions however come in handy!!!!
Thanks very much for your time.
Porter

Hi Porter

Its a little hard to estimate some of these things without good
input data.

In general I don't have any problems with the advice Jeff has given
, but you will note that within that is an attempt to estimate the
power load for your system.
Depending on this there can be different advice given.

Also your stated two alternatives are inconsistent.

No1 uses an inverter to provide 240v and No 2 does not.

You either have a need for 240v from the car or you don't.

In looking at the list of bits you wish to drive the camera's are
quoted as 9w each , but do they require 240v or 12V ?

The laptop may be one of those the uses a 14-15v like most
Toshiba's and could be run of 240v , or via the more efficent
direct connection to 12v.

The UHF would be 12v , but the chargers , I assume 240v.

In the systems I design I usually configure them for as
much as possible from the one power source as far as possible
and maximize efficentcy.

We could provide better answers if you could list more about
your equipments voltages ,power and usage requirements.

Is it feasible to run the car for some time during the 10hours
if batteries get low or must the system run unattended.
If possible to run car this will minimze your power needs.

Robin Miller

Hi Robin,

Thanks for you time!
As i may have said, i am just beginning to educate myself in this type of thing and have just posted what i have been told thus far, sorry.
I have a sony Laptop, trying to get the amps usage from sony is like pulling teeth. The closest i got was 1.4watts, but that from what i learnt this is impossible.
Yep, the cameras have a 12v power supply.
Yep, the chargers run nomal household power supplies.

In option 2, i wasnt given full details, just a "hey have you thought about this?" type thing, but i would dare say your right, an inverter would be necessary.

In my game, when you pull up for a job, its a case of invisibility, running a car is out of the question, it would draw attention to myself and that would blow my chances of a perfect result.

Any further advice and education is most welcome.
Thanks again
Porter

Porter,

I don't know what type of car you're ,but could you "inconspicuously" fit any solar panels to it? If the weather is reasonable it would be keep the battery(s) charged to a greater or lesser degree whilst the car is parked.

Solar panels fitted on 4Wds are quite a regular sight these days.

Just a thought.

Bilbo

"In my game, when you pull up for a job, its a case of invisibility, running a car is out of the question, it would draw attention to myself and that would blow my chances of a perfect result."

whats a perfect result? Sorry but though Im sure you are a reputable operator, I have a friend who is on compo and has had to put up with this sort of "surveilance", mysterious flat tyres etc

I am sure you have come across the insurance companies that arent interested in a "result" that shows a person to be genuinely injured. Hoping to get footage of him holding his child or changing a flat tyre etc.

Fisho,

I agree with ya to some extent. My brother has just been through all that with insurance companies. Basically, he's crippled for life and all he got from Workers Comp insurance companies was the runaround and finally an $80 K payout. Not much is it for a welded up spine, pain treatment for the rest of his life and he'll never work again. He's mentally and physically stuffed. He was reputed to be one of the best boilermaker/welders in W.A.

HOWEVER, my own insurance company did do a fair job in trying to find my recently stolen Landruiser. So perhaps Porter is a good guy. Who knows?

Plus there are all sorts of Workers Comp claimants that aren't genuine as well as ones that are.

Bilbo

Well Porter 33333333333
Welcome to the Forum of true wisdom , mate you will leave here educated and well informed I can assure you, just read PostID: 39933 and you will see exactly what i mean,so much information your brain will overheat.
But if you seek information about 12 volt electrics then Derek will be your man,find his Adds ABR in the sides or at the bottom.

Doug

Wow, a fair mix of responses.

Ah, ok, here goes.
BILBO,
I drive a non-descript Nissan sedan.
I have thought about a good solar panel on the rear parcel shelf but the windows are heavily tinted, will it be effective?

FISHO64,
The perfect result?
The perfect result is where i spend 10 hours cramming my broken 6ft 3" into my sedan at the request of a client to prove or disprove a claim.
During that 10 hours, i report only what i see. I refuse to report what didnt happen, altho there are insurance companies the prefer you to find something, creative photograghy its called.
You, see, i am on compo too, i was broken in the defense force, and i am also hounded and pressured and followed, by my own people.
If my subject drops his keys with a bad back i will record that, i will not say he was gardening.
I hope that in some small way lifts your opinion, if not of investigators, then maybe of me. I could justify my position further if you wish, but you sound like a decent bloke and no-one can be blamed for defending their family and friends

DOUG,
ha ha ha sounds like listening to my old Section commander stumbling thru orders!!!
ha ha

Thanks for the Tip i will have a good look into that.
Cheers
P33

Porter,

Forget the solar panel on the tinted parcel shelf,,,,,,,,,,

One, it wouldn't work as it's in the shade (mostly)

Two, a small solar panel that would fit on a parcel shelf wouldn't give a big enough output to keep up with what you're doing to the battery.

Bilbo

Go a twin battery set up with an inverter.
We are photographers and photojounalists and run laptops and digital cameras which need batteries recharged all the time. Enables us to work on the road, at night on the move or at rest. We have never flattened the battery and this is even with the fridge running too!
Phil