Has anyone else had this problem. I am pretty new to MDing and reacently bought some NiMH (Nickel Metal Hydride) batteriesfor my XLT, which is pretty well used but seems to work fine with alkaline batteries. While detecting the other day, for the first time with the new NiMH batteries in the machine, it shut down for no good reason. The machine also would not start twice with these batteries powering it. I went out for a couple of hours today. First thing I try to start up with the NiMH batteries and it won't even come on. I switch to some alkalines and I have no problems. Has anyone else had this problem, any ideas?
New NiMH batteries are sold uncharged. Did you charge them before trying to detect? I always used NiMH batteries in the XLT I had & they would charge up to 11.6 volts, quickly drop below 11 volts & spend most of their useful life at 10 volts or so. Once they get a little below below 10 volts they drop quickly & the detector becomes unusable at maybe 7-8 volts.
I assume you observed the corect polarity if you were using individual NiMH batteries & not the White's pack? I assume you're sure the battery charger works OK? It would be unlikely the NiMH batteries would be defective, but as I said they do come uncharged. Are you able to get a battery voltage indication on the XLT? Are you able to use another battery tester to check the batteries?
I don't know if the following applies to detectors, but sometimes the remote for the TV would quit working & before assuming dead batteries, I would spin them around in the remote. This usually made the remote start working again. Perhaps this helped clean the contacts? HH, George (MN)
Are they Made in China? I bought some NiMH batteries for my digital camera, from Harbor Freight just to see if they were worth a crap. They are not. Total garbage. Tossed them and bought quality.
I bought some Kodak NIMH batteries and a 2 hour charger for the digital camera and they seem to last alot longer than anything I ever tried before. I am going to give them a shot in an XLT I am buying.
Shouldn't have any problems with NiMh. Couple of things to note and a couple of questions for ya~
Note : Quality of the manufacture~ I recommend Energizer or Duracell. Other brands dont last real well
and you get what you pay for.
Note : Buy NiMh batteries with a mAh rating of at least 2800mAh as they will last much longer.
Note : Charge new NiMh batteries at least 10 hours *over night* before use and recharge about every other
day. Dont let these batteries sit for more than a week or two unused as they will self discharge.
Questions : What brand did you buy? What were thier mAh rating? Did you charge them overnight
before use?
The notes are my experience with common problems I've had with NiMh batteries in the past. If the notes
dont help then I'm at a loss as to what may be occuring with your machien other than the voltage regulator
may be having problems and might need to get looked at. Also make sure the contact of the machiens
battery connections are clean and in good shape.
As long as you keep dropping coins I'll keep finding them.
The problem with NiMH and NiCads is that they are only 1.2v capacity. Alkalines are 1.5v. You can charge the NiMH higher but they self-discharge to 1.2v in a few hours . . . and continue to self discharge the longer they are off the charger. Not as bad as NiCads but it happens. They also have a different discharge curve than Alkalines, which hold a higher plateau voltage longer. Some units built for Alkalines just don't work well with rechargeables. Short life, less response, etc.
Whites XLT, Minelab Excalibur II, Whites Beach Hunter ID, Whites Surfmaster II, Whites TM808,
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Re: Trouble with NiMH batteries in my XLT
You can try a couple of things:
1- make sure the contacts are clean on the battery itself.
2- try to discharge the pack fully before trying to recharge it by connecting a 12Volt 10-15Watt light bulb (ex. car turn signal light bulb) and monitor the voltage on the battery untill it reaches about 1-1.5 Volts. Then use your whites charger to slow charge the pack for about 16 hours. Try not to leave it for longer than that.
3- to test if your battery pack holds most of its charge you could try to connect the same lightbulb to the battery pack terminal and the light bulb should remain lit brightly for at least 1 hour.
4- try to look inside the battery compartment and see it the battery terminal contacts are not bent out of shape or off to the side. Sometimes the connectors bend too far back away from the battery contact point and it is barely making contact with the battery and all it takes is a slight bump and the lead disconnects the battery and your detector shuts down.
You can forget about Engerizers or durocells NiMh.batteris I tryed it here too fully charged
it did n't work on my White's XLT either, Mine won't turn either with those NiMh. batteries too
I guess I go back to some alkaline batteries.
I've used NiMH in my previous XLT and am using them now in my MXT and IDX with no issues. Couple of other points that haven't already been covered by the other posters, check for any black tarnish or other strange deposits/goop on your batteries. That may prevent proper contact. Use a proper NiMH charger as a Nicad charger may not properly charge them fully. Or you may have had one bad battery.
Although NiMH are only 1.2v per cell and 8x1.2v=9.6v versus 12v for 8 alkaline, the XLT/MXT runs just fine on that voltage. Alkalines lose their voltage gradually -- as opposed to rechargeables like NiMH or NiCad which maintain most of their voltage over the whole charge and then suddenly plummet. (Be aware though, as stated earlier, that NiMH do lose voltage over time if not being used, so charge them again before going out if you haven't used them for a couple of weeks. The new Hybrid NiMH have all but eliminated that problem now.)
I've got NiMh in my XLT and it works fine. While they are rated at 1.2v they charge to 1.5v and drop to 1.2v and stay there for most of the discharge cycle. The graph GpSnoopy put up is a great example. I charged my batteries a few days ago, hunted 2 hours this morning and the voltage check is still showing 10.6v
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