charging metal detector battery when living in the bush?

How much will charging the detector battery drain the car battery? Can you bring extra car battery for charging detector? What is the best solution?

Hi GH,

Great Question!

Ange and I were discussing this one the over the weekend. We have begun to look at solar-charging etc. as I am reluctant to charge off the car. The last thing I want is to be stuck in the bush with a flat car battery and being a shallow cycle battery, once flattened it really shortens it's life.

I am very interested to here what others members do to combat this problem.

Nature Pete.

GH wrote:How much will charging the detector battery drain the car battery? Can you bring extra car battery for charging detector? What is the best solution?

G'day, a second battery is a good idea, you can then charge your detector battery and run a fridge ect from it. It can be connected to the main battery for charging but make it has an isolator ot disconnect from the main battery when the volts drop to a certain level, so as you can always start the car.

I use one of these "Redarc" isolators. http://redarc.com.au/products-and-services/sbi-series-dual-battery-isolator/smart-start-sbi

Also have a solar panel to keep the second battery topped up if camping out for extended stays.

cheers dave

G'day GH.

If your car battery's in good nick and your alternators charging properly,by starting up your car and letting it idle for a good 15 minutes a day,or even better drive it for the same amount of time,(unless your running other accessories as well at the same time) you will have no problems charging 2 GPX batteries consecutively or individually per day. Carrying a spare fully charged car battery with you is alright as long as its being swapped over with your main car battery every now and again(when low) and recharged occasionally.A safer and easier bet would be to invest in a portable jump starter one that has more than enough cranking amps to jump start your vehicles flat battery,some of which also have the benefit of running other 3,6,9 and 12volt appliances,as well as being capable of being recharged from your own car battery whilst driving.

Cheers kon61.

Thanks Koni. I am planning a trip and although I have two batteries, getting them charged via the car has been a bit of a question in my mind. I think a jump start pack is probably good insurance if you are out somewhere. The other thing is that I run a CPAP machine (to fix my sleep apnea) off 12 volt batteries and I would also like to be able to charge them. I have two, which I estimate can give me about 40 hours of sleep time. From what you are saying though, if I can top up the car battery with a short run, enough to charge the detectdor batteries, then there is also probably enough to even run the CPAP directly off the car battery which I can also do, although prefer stand alone gel battery. I don't have a charger to run off the car lighter outlet to recharge the 12 volt batteries. can you recommend anythign there pls ? cheers.

G'day Imadogman.

Forget about charging 12 volt gel cells from your cigarette car lighter via your car battery unless you have,as Dave stated,an isolator so that your battery levels never fall bellow cranking amps.Get yourself a solar panel which offers more than enough watts to recharge your gel cells independent of your car batt,or a more expensive option,but one that offers a wide variety of purposes,would be a small portable four stroke generator.

Cheers kon61.

Some questions.
Take a dual batt isolator, setup to charge an Aux batt in the rear of your ride. Run a fridge from that batt and also have a solar panel connected to it.
Does the voltage now keep the two batteries connected in parallel regardless of ignition being on or off.?
Effectively charging both start batt and Aux batt.....or flatting both as the panel keeps the isolator from disconnecting.?? ie...volts above 12.7v keeps them joined in parallel.
Now work out whether or not your getting enough Amps from your panel to support your Aux usage during the day...because once the sun is gone down its only now when the voltage drops below the cut off that the two batt disconnect.??

Just a thought.

The Smart Start SBI should now be operational. Start the vehicle or apply a charge to the main battery.
Once the main battery voltage rises the Smart Start SBI will activate, you will hear the solenoid click and see the LED illuminate. Now
turn off the vehicle or remove the charge to the main battery. The Smart Start SBI will disconnect the auxiliary battery once the voltage
on the main battery drops, you will hear the solenoid click and the LED will go out. Note: The amount of time it takes for the battery
voltage to drop low enough for the solenoid to turn off will vary due to battery condition, age and state of charge. (For a new, fully
charged battery, it may take days).


All interesting stuff.

A dual batt isolator will keep both battries connected in parallel untill the volts have droped to around 12.7v, this is what I have found to be the case.

Having a solar panel connected into the same system it will stay connected the same until the volts have droped from useage to about 12.7v.

If you want it to disconnect quick, just turn the head lights on for about 30sec and you will hear the isolator click and it is disconnected, turn off the head lights NOW.

It dosn't seem to be a problem it it stays connected until it gets dark in the evening and it is ready to disconnect by its self when the volts have dropped to 12.7 and keeps your main start battery with plenty of charge in it.

cheers dave

I think a better way to utilize these things is to have the isolator connected to a 3 stage DC charger connected to your Aux batt. This method will charge your Aux much better than any electrical switch like an isolator.??
Just my thoughts.

Yep I reckon that you may be onto something there.

cheers dave

i would suggest getting a duel battery sys in any vehicle going into the bush. the cruiser 15 plate batteries will charge a detector battery no probs. my system is wired up so that the secondary battery is compleatly isolated when the ignition is off and i draw no power off the secondary battery while i am stopped.in the last 25 yrs i`ve had to give myself a jump start about 5-6 times
cheers dave

I'm thing a small portable generator is the most versitile approach. And probably cheaper than solar considering all the set up costs (I'm no techie). Even bunnings special for $150 (750W) looks OK provioded I don't fry what it is I ma running or charging. Any thoughts ?

Hi Steve, generators are a must have item when all else fails.
However, some if not most are not regulated on the 12v charging side, so you could over charge your battery if your not careful.
You would be better off with a 240v 10-20Amp smart charger running off the 240v side of the genny, that way they will fully charge quicker and there is no guess work.

Thanks Narrawa for your input! Cold beer with me next time! I ended up with this off E-Bay:

Pure Sinewave Camping 4WD Generator Power 240v 12vdc

For the price of $305 I think it is better option then the two stroke Homelite for $150. The sinewave technology appears to cater well for electronic equipment. I will use it to run chargers for GPX and other items. As well it can run lighting and even a fridge. Starting to sound like the Hilton! It may be a bit of overkill to charge batteries but at least it will get the job done and is easily shifted between vehicles. It would also be able to charge my car battery if it went flat for some reason and run a range of powertools. Potential use for rotary hammer drills as well if ever I need to play with that WA cement! That thought crossed my mind after seeing Jonathan Porter at it for a couple of hours with a hammer and chisel.

Things are shaping up well for Tiboburra in October. Would be good to catch up before then. cheers.

Messed up the link: http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=170680453669

Narrawa wrote:Hi Steve, generators are a must have item when all else fails.
However, some if not most are not regulated on the 12v charging side, so you could over charge your battery if your not careful.
You would be better off with a 240v 10-20Amp smart charger running off the 240v side of the genny, that way they will fully charge quicker and there is no guess work.

Good to know Narrawa, I was about to buy a standard generator to go bush with to charge my detector battery. My budget will not stretch to a Honda ($1K plus) pure sinewave version. Might have to do some footwork to see if I can find a cheapish generator like you mentioned above. Any ideas anyone????????

Also have a solar panel to keep the second battery topped up if camping out for extended stays.

cheers dave


[/quote] Hi Dave,can you tell me what size solar panel you use for your battery and fridge? cheers