Camping and charging detector batteries

[bbrook]

Hi all ,just wondering how everyone goes charging a gpx battery away from the mains .
I'm planning an overnighter and will probably need to top up the battery .
How much power do they suck if charged from the cig lighter in the car . The car batt is in good condition , but I would rather not have to jump start it when home time comes !!
thanks , Brett

 

[Christos57]

I have a 1900 amp jump starter that I use to charge mine and the sdc, it lasts a few days before it needs to be charged

 

[Jaros]

All those details should be on the spec sheet with the detector or on google?

 

[Westaus]

Howdy, this link here goes into lots of details - https://www.prospectingaustralia.com/forum/viewtopic.php?id=9156

It should give you some ideas of how little and how much power you need.

I have a 1900 amp jump starter that I use to charge mine and the sdc, it lasts a few days before it needs to be charged

For an overnighter these would probably do as well. However you can find the battery goes after a while they have not been the best quality in the past.

 

[condor22]

The answer is variable,

The GPX battery charge time will firstly be dependent on how many hours you have used it before you charge it. However process is equally important.

So here's my tip for charging from the vehicle battery via cig plug;

Assuming you are out most of the day and you are driving from camp to your detecting area and that the battery is already fully charged.

• When you break off for lunch, plug the GPX battery into the car while you eat.[/*]
• Every time you move location plug the GPX battery back in to charge it.[/*]
• When you leave to go back to camp, plug it back in.[/*]
• The next morning, plug it back in on the way to your next detecting area.[/*]

I've found that in winter in the VIC GT I don't start detecting till about 9.30 -10 am, too bloody cold. I break for lunch for about 1/2 hr, then detect till about 4.30 so I can get back to camp before dark. I'm out there to enjoy myself, not "bust a gut". Having said that, my power up time per day is about 6 hours max, which is about 1/2 what the battery will provide. The charging rate should not flatten a vehicle battery provided that battery is in good condition. Also the Lithium Ion battery will last longer if you don't cycle too deep between charges, so constant little charges are better for it and definitely won't cause your car a problem.

If you're worried about the car battery at lunchtime, idle the engine while you are charging the GPX battery.

 

[Chewy]

Yeah great advice above. That's pretty much what I do if I'm out bush. Charge it in the bus on the move. I do sometimes charge it off the car while it's parked at camp to. I take a little lithium ion battery jump starter pack with me to. Bloody awesome lil thing. Jumps ya about 20 or 30 times before it needs recharging. I also charge my phone from it. Great as a power source in the bush.

 

[condor22]

Went out to my 4x4 after my last post. I connected my GPX battery to my Aux battery which has a monitoring system on it. I don't think that I've ever had it on charge for more than about 4 hours from a days use. ( not being charged during the day)

Anyway the 12VDC charge connection pulls 1.4 Amps, so even at 5 hours it will use about 7AH only. If that causes your vehicle a problem, then it's about time to look at a new battery

 

[bbrook]

Thanks everyone .The jumpstart battery pack sounds like the best option

I have been meaning to look into them cause the old ute only gets shifted round these days and always seems to be flat . I didn't realise they had 12 volt out . The li-Ion ones look great but I don't see one with a cig.plug

Thanks for doing the test condor Next time I go out I will recharge off the car when I get back and see if it still kicks over
thanks Brett

 

[Flyspray]

Don't know if this helps, but until I figure out what I want to do, I've been charging 4 x 5000 mAh batteries from my car battery, which is: 620 CCA, 120 RC, using the lighter socket. The car battery has 12.3V before starting and 12.15V when finished. Takes about 10 hours to charge the 4 batteries to 100% from flat. Did this at home first, in case the car wouldn't start, but it starts no problems. And as a precaution when out in the bush I start the car every now and again while charging. Mabe if Condor22 reads this he can tell me if I'm doing any damage to the battery?

 

[condor22]

In short, I don't know, because you don't say what the batteries are. The standard lead acid vehicle starting battery typically charges at 13.8VDC, and; As smart charging is recommended for the following for each mode for Deep cycle batteries

BOOST - Voltage steadily increases to the level of the set Absorption Mode - Current (Amps) is steady at preset Max

Absorption - Voltage remains steady at preset value, Current gradually reduces;

GEL = 14.1VDC
AGM = 14.5VDC
LEAD ACID = 14.9VDC
Calcium = 15.3

Float - Voltage reduces to a preset steady value, current gradually reduces to almost zero when battery is full;

GEL, AGM, LEAD ACID and Calcium = all 13.3VDC

These figures are from the Redarc BCDC series, but are indicative of smart charger algorithms.

Lithium batteries should only be charged with a suitable charger matched to the battery which will maximise battery life. If you think about it, most mobiles, tablets etc come with a 240VAC charger that steps down to 5VDC and sometimes with a cig plug charger with inbuilt voltage reduction as well as current limiter. There are so many types it's impossible to give exact info. But what I will say is, charge to quickly and ***BANG*** (This is re current)

Re voltage - 12.3 to 12.15 is getting low and will most likely not fully charge another 12V battery 100%. Any battery not fully charged on each charge will obviously not give the maximum output and any incorrect charging may reduce overall battery life.

Consider that the Minelab GPX 7.4V Lithium comes with both 240 & 12 volt charging options, however it my understanding that the charging control is inside the battery. The mains and car chargers are in fact just power supply interfaces.

Like I've said before, taking the "easy" way out (or should I say cheapest) invariably ends up being more expensive in the long run.........

 

[Nightjar]

You blokes take the joy out of this great hobby, smart charger algorithms etc etc, worrying about the simple life.
Plug both 4500 batteries into 12V sockets at end of the day before driving back to the camp, unplug them next morning and away we go for another day. Original batteries bought with detectors in 2008 still going strong. (Have never used the 240V chargers.)
During the off season the batteries are put on 12V charge in the shed about every month to keep them fully charged at all times.
Bought a dead GPX battery late last year and renewed the Li-Ion batteries so now have a spare for this season.

 

[blisters]

... The car battery has 12.3V before starting and 12.15V when finished. ...

12.3 sounds a little low maybe only 70% charged at 25C and you are dropping it more than a further 10% down to 12.15. Put your vehicle on charge for 14-16 hours and see if your initial vharge increases. Leave it 3 hours before measuring. If it doesn't sit around 12.6 then your battery might be on the way out.
Jon

 

[Flyspray]

Thank's for the answers all, and sorry about the 'handyman' type question Condor. I started out describing how I do it at the moment, and then wondered if I was damaging the car battery. Going to see if I can get it up to 12.6 now

 

[BigWave]

Top man Nightjar. It's not rocket science. A few A.Hrs won't kill your healthy car battery. Let's not turn this into a Cecil B. DeMille production.

 

[condor22]

BTW 12.15 V on a car battery is about 50% charged, 11.4 is flat and about 12.6 after it's rested is 100%

Proper battery maintenance and correct charging is "Rocket Science" if you want to look after your gear and batteries properly.

 

[bbrook]

Hi again ,just a follow up . I ended up getting a jumpstart battery pack , kept my eye on the catalogues and picked up the 1900 amp at super cheap last week for $120 ( still on special for a week or so ,I think)
Worked a treat ,detected all day and charged the battery up over night , jump pack still says fully charged

thanks Brett

 

[bigkingsalmon]

Hi. Will a sca 900amp jump starter pack 17 A/H battery (supercheap auto $119.00) charge a minelab detector battery? If so how long would it take? Overnight? Are there any better options to charge the detector battery only? I'm not real cluey with electrical stuff. Thanks.

 

[Nightjar]

BKS, Replied to your question on the other site. No problems with charging with what you have and yes if need be plug it in and leave it overnight.

 

[davent]

I would like to read the reply to mate, will check out a few other sites looking for it! Cheers dave.

 

[mbasko]

Here Dave:
http://golddetecting.4umer.net/t23704-charging-minelab-lithium-ion-battery#228791