Noob with Excalibur II battery charging question

[beachdude]

OK, I have waded through pages and pages of the sticky thread on batteries 101 but I can't really find a simple answer.

I have the stock charger and the battery pod that came with the detector. After hunting for 6 hours or so, should I recharge the pod? For how long?

Or, should I fully use up the charge in the pod and then recharge it?

Finally, does the Excal II charger shut off automatically when the battery pod is charged? (it just looks like a transformer to me and I can't see any lights on it or anything to indicate whether it is on or off).

Thanks,

 

[Critterhunter]

While I've never had an Excal battery in my hand, from what Kered has said about charging his there is no charge circuit in the battery, and being that the wall "charger" is just a transformer...Yep, it doesn't cut off the charge when done. Nimhs don't suffer from memory problems so no real need to drain it before charging again, but just the same Nimhs still benefit from draining near dead before re-charging say 2 or 3 times a year for about 3 to 5 cycles in a row to excercise the pack and get more capacity out of it. When brand new they also benefit from this and will increase capacity/give longer run times by doing that.

From memory the Sov/Excal drains around 50 to 69ma or so in current draw, so 6 hours times high balling it to 70ma= how much capacity taken out of the pack. Look on your wall transformer. What is the ma output? I think off hand it's either 100 or 150ma. Divide that into the capacity taken out of the pack from hunt time and that will tell you roughly how many hours to re-charge it. Roughly about half the time you hunted with the pack, but I'd overshoot that by about an hour or so because charging is not very efficient so it always takes a bit longer than the math says.

If you have a volt meter another way to check if the charge is done is by reading the voltage while the pack is still hooked up to the charger. Write down the #. Come back in an hour and re-check it. Is it lower or the same as before? Then it's probably done. Re-check in half hour. When a pack is done charging it drops a bit from peak voltage and then sits around that #. But it also will dip here and there while charging and then climb back up again, so don't assume the first reading you take that shows it has dropped means it's done charging.

 

[Tin Fin]

Do the math and charge it based on time. I always check the battery with a voltmeter before charging, just so I know what it is when I start charging. With the standard charger, it won't shut off - Critter has that right. With an after-market smart charger, it will shut off and then go into a trickle charge mode. If you accidentally leave the machine on - like I did once - the battery will be flat dead when you try to use it again. The smart charger wouldn't even recognize there was a battery there. The voltage was down to something like, 2v for the whole pod But, I used the original charger, charged it based on time, and measured the voltage after. I have not had a problem with that pod since. I can use either charger on it now. But if I use the Minelab charger, I always measure the V, and charge based on time the way Critter has written up.

 

[CNY Treasure]

I found this article last month and bought the GWS-MC-2002 Quick Charger on eBay for about $25. I can use it with my car battery or at home with a 13.8vdc 3amp power supply. I can charge 8 nimh aa's in less than 15min. and they wont even feel warm. My Excall battery is lasting so long I have not charged it yet. (still @ 12.5v after 8hrs) But this charger is worth it IMO. Ill post how long it will take to charge it later. I am thinking about buying another for a backup. Vic

http://metaldetectingforum.com/showthread.php?t=55045

 

[CNY Treasure]

It takes 20 minutes.

Vic