Charging and Re-charging of SDC 2300 and GPX batteries???

[~LARGO~]

Hi all,

I need to know when our rechargeable batteries need recharging, because of use, or simply not being

used for some time, do they need to be completely discharged, or can we recharge them without going

through this timely process?

PLEASE, no speculation or personal opinions!

And if there is a different process between the SDC 2300 rechargeable batteries and the lithium ion GPX batteries,

would you please explain?

I know all rechargeable batteries lose power pretty quickly, especially the nickel metal hydride batteries. I don't get to use my detectors as often as I would like, so I need to keep all this in mind, while they are in storage, and after I remove them from storage.

Thanks very much!

Gary/Largo

[Reno Chris]

The SDC batteries are NIMH (Nickel Metal Hydride, very different from Ni-cad) and the GPX is a Lithium ion as you said. You can do your own research on the internet as far as storing these batteries, then you will know that what you read is not the personal opinions of the members of this forum.

[~LARGO~]

Hi Chris,

Thanks for reminding me about what the correct SDC 2300 batteries terminology is! I was winging it off the cuff, as I am trying to get a lot done today, and get my machines packed and into temporary storage.

Nickel Metal Hydride is correct!

Thanks,

Gary

As an aside, you won't believe the solar gear I have accumulated since you went on your jaunt to Alaska earlier this year. Folding solar panels, several, lights, lanterns, solar generator, some free stuff from Goal Zero. I think it will be handy to have on hand. I found the Litehouse 250 lantern is especially cool and handy in several ways, besides providing excellent light!

[DOC]

DO NOT fully discharge NiMh or Lithium Ion batteries. They do not develop a memory like the old NiCd batteries did. So if you use either your GPX5000 battery or your SDC2300 battery for 2 hours, throw them on the charger and top them off.

If you totally suck a Lithium Ion battery down, or a NiMh, by letting them lay around, or leaving them connected to your machine, evenif your machine is OFF. You are probably not going to be able to revive them. Even though your machine is off, I have a bad feeling that they some how still manage to drain batteries.

I have personally NOT had good luck with storing NiMh (Nickel Metal Hydride) or Lithium Ion batteries. I have heard all kinds of theories. Store them fully charged, store them with some charge.

I have been using the same batteries Lithium on my GPX5000 for 4 years. I leave them on the charger all of the time. I intend to do the same with the NiMh. I use computer controlled chargers that shut down after the battery is fully charged and then monitors the battery and tops it off as needed. I have had zero problems with this. It is important that the charger actually stops charging the battery. And monitors the battery only tuening on when needed. You do not want to use a TRICKLE charger on a Lithium Ion battery because it will overcharge and overheat.

It's akin to a car battery, leave it sit it dies. Use it every day it's fine, because you are throwing a charge into it. If the car is going to sit, you put a float charger on it to keep it topped off.

I've sold about 5000 batteries. I have listened to 500 stories of success and failure. Success stories always the same. Use the detector every week or they keep batteries on the charger, Failure, "Last time I used it was a year ago. It took me a week just to find the charger." Or, the battery caught on fire while charging. "Yeah it was July in Las Vegas it was 114 degrees, I was charging the Lithium Ion in the garage with the door shut, probably 120 degrees in there." Add to that the heat that is generated by the battery being charged and you have far exceeded the safe charging temperature of 113 degrees.

Or the person who got some batteries from some guy who had not charged them in a year. He put them directly on the charger without checking them with a voltage meter to check for viability. NEVER NEVER NEVER attempt to charge a Lithium Ion battery or any battery that shows ZERO 0 volts. This is an indication that the battery is totally dead. It has probably began to deteriorate inside and could have eaten away the insulation between the positve and negative leads causing a dead short. So now when you charge it, you simply heat up a piece of lithium, and surprise, surprise, the battery explodes.

By the way, when a battery says it is 1.5 volts. like a AA, or a C cell. 1.5 volts is when the battery is DEAD. If you check a fresh AA you will find that the voltage is 1.58 to 1.60 volts. When you get down to 1.5 that battery is basically shot.

So your lithium ion batteries that are 7.2 to 7.4 volts... those batteries charge up to a full charge of around 8.3 volts. So your full day of operation basically uses around 1.1 volts. The difference between 7.2 and 8.3 = 1.1 volts. If you charge a 7.2 to 7.4 volt Lithium up to full charge and your voltage meter only shows a 7.8 volt charge you have a dead cell(s) and you will probably only get around 4 hours of run time. Time for a new battery.

So there you have it, MY OPINION based on a lot of personal experience and a lot of information gleaned from customers.

Take care!

Doc

[~LARGO~]

Hi Doc,

I was hoping you would chime in!

Thanks very much for the in depth information.

I know the GPX 5000 lithium ion batteries lose their charge pretty slowly

when not in use.

The SDC rechargeable batteries lose their charge a little faster it seems.

I hope I didn't screw up my GPX battery, as I was trying to exercise the

battery by leaving the machine on today, and forgot about it... So now I

have the battery on the charger. I hope it takes a charge fully, we shall see

in a short time...

Thanks again, Doc! So happy to hear from you again!

Happy Thanksgiving to you and yours Doc, and to all my friends across the miles!

Gary Long/Largo

[~LARGO~]

Hi all,

I had checked the charge level of the battery on my running GPX 5000, as the day progressed, I think the last time I noted the charged level left, I think it was 7.4. Later, when I remembered that I had left the machine running, it was one of those oh darn moments...really a little more than oh darn, like oh snap! ;-) When I checked the charge level, nothing would come on. So I put the battery on the charger, it went through the usual start up colors on the little light on the battery. I waited for some time, thinking it should be charged pretty soon, but it was not yet fully charged. When I went to bed, the battery read 7.6, so I thought maybe I dodged the bullet, as I had been very worried that I might have toasted my battery, as Doc indicated that might be a possibility.

This morning when I awoke, I went to the room where the battery was charging, anticipating that the charge color may have remained the yellow color, meaning the battery had not charged fully. What greeted me, and I am still a little anxious, was the pleasant green color of the battery charge light. The charger was cool, so it had stopped charging, but just enough to maintain the green light. Hooking the battery to the 5000, the battery test said 8+, whatever that means. I am not sure if it means it is charged fully or just charged beyond 8 just a little, so the jury is out until I can get the detector out of temporary storage in a few weeks. I had just traded in a new lithium ion battery for about $150 credit on a new detector I could have used if mine had gone bad, but hopefully mine will be all right.

Gary/Largo

[azblackbird]

I don't know about you guys, but I learned a lot about Li-Po's from the RC world. I keep all my Li-Po's in the refrigerator when not in use at an approx 40% charge. Supposedly they can last for years in that state with minimal draw down. When I pull them out, I let them adjust to room temp, then I top them off and am good to go. Before putting them back in I check the voltage, if low I charge them a little bit, if high I turn on whatever they came out of to draw them down a little. So far so good. After 4 years, my batteries are still going strong with minimal loss of storage.

Here's a site with some very good information on lithium based battery storage and charging.

[Steve Herschbach]

You and I are exact opposites when it comes to batteries Gary. You put a lot of thought into it, and I barely think about it at all. I just keep my batteries charged, always have backups, and toss them if they go bad. NiCads were never worth owning for me but the new batteries are pretty trouble free and quite forgiving in my experience anyway.

[azblackbird]

You and I are exact opposites when it comes to batteries Gary. You put a lot of thought into it, and I barely think about it at all.

What can I say... I'm anal. At $200 a pop for the TDI Pro batteries, I have to be.

[~LARGO~]

HI Steve,

I guess I need to respond as my name is Gary, and I have no idea what Az Blackbirds name is, and he responded to your statement, so I don't know where I fall in the conversation!

I have sets of rechargeable batteries, two different brands, 4 each Powerizer, which I believe came with the SDC 2300, and 8 each Tenergy, both 5000 mAh. I have not used any of the rechargeable batteries, but I did use some back up for the back ups, being Ray O Vac Ultra Pro throw aways, which I found at Batteries Plus for a pretty good price (cheap), just to try out and compare their usage life, mostly as a favor to a Minelab dealer. The Ray O Vacs have no mAh statement on them, but I ran 4 of them for the better part of a day, and they still read in the range of 1.74 or so volts, so I thought that was interesting.

So it's not like I am heading out being totally unprepared!

I now have a Goal Zero Yeti 400 solar generator, a Goal Zero 30, like yours, which, oddly enough, I bought at a Costco Goal Zero demo in October, at a good savings! I hope to try all of this I will try out in a few months, after my wife recouperates from her upcoming surgery in January, likely will put me out of any detector uses until the early spring.

Always good to hear from you!

Gary/Largo

[cobill]

Doc, what is your recommended computer controlled charger(s) you referrenced above: " I use computer controlled chargers that shut down after the battery is fully charged and then monitors the battery and tops it off as needed. "

We're all lost in this charging game!

Bill