Sovereign battery question

[Md Epidemic]

I bought a used Elite in November went out about 3-4 times and have not used it since. So on friday I take her out
and the battery did not last 2 hours and ended up using the AA battery holder. I had charged it over 20 hours 6 days prior to use.

I don't think the previous owner used it much and the battery went bad from storing with no charge. He sold me 2 rechargeables and a AA holder.
I have not tried the other rechargable but might be in the same condition.

My question is what are my options with the rechargeable packs. I'd like keep the AA pack as a backup

Thanks,Epi

 

[Critterhunter]

You might be able to revive that battery. Hook a car tail light bulb up to the two battery leads (put it on a cement floor so the bulb's heat doesn't start a fire) and let it go until the light dies. Once it dies let it sit connected for another 2 or 3 hours to make sure it's good and dead. Recharge it again for about 25 hours (it will take more time than 500ma of the charger divided into 1000ma (if it is that) for the battery....which equals 20 hours)...Because there is energy lost that makes the charge time actually longer than 20 hours. Do this discharge/charge 4 or 5 times and then see how much run time you get from it.

If you had an aftermarket charger that lets you set the amps then here's what I do to revive them. I give them a blast charge of say 1 or 2 amps which will break down crystals that form in the cells. Some guys even charge even higher, like say 5 amps for a 1000ma pack...But that can be risky and cause a fire. Feel the pack and see how hot it is getting when doing this and for God's sake do it in the middle of a cement floor. But still, without blast charging the pack you should be able to revive it by charging/discharging. After one good blast charge and draining then I do a nice slow charge like the stock charger will do. I've revived nimh and nicad drill batteries and several other nimh/nicad rechargeables in devices by doing this.

 

[Ron from Michigan]

Epi,I would try the other rechargeable pack.Usually if you have one good pack a charge overnight will get through long hunts without changing to the alkaline pack.The pack that only last for 2 hours could still be used as an emergency backup.However,I would use both packs and log in time use before running down,maybe it sat around too long before using.One option you could take the bad pack and install 10 AAA batteries.This would require a trip to Radio Shack to purchase 2 alkaline AAA battery holders that hold two batteries and 2 alkaline AAA battery holders which hold 4 batteries.These Alkaline packs have wires that can be soldered in a series to create a 12V pack and can be inserted into the old pack with the old batteries removed.Good Luck Ron

 

[Md Epidemic]

Thanks for your replies. I will try and revive that one battery and charge the other before i do anything else.

Also forgot to add I am using an Explore SE charger. I remember reading in this forum that it was the same charger.
Is it OK to use this charger?? The reason is, when it arrived it had the wrong charger (excalibur) and since I had recently pulled the cable out of mine
I figued I would keep it.

Plus didn't want to complain to the seller.

HH, Epi

 

[Critterhunter]

Hmmmm....I think the Explorer has 8 cells in the rechargeable pack and not 10 like the Sovereign. That doesn't matter on an advanced charger which will automaticly determine the number of cells, but we are talking about a transformer here with a static voltage output and not an exotic charger that can increase the voltage based on how many cells it senses in the pack. It could very well be that that transformer isn't putting out high enough voltage to charge 10 cells, as it's only a power supply and the "charger" (which is VERY primative) is in the GT's rechargeable pack's case under the charge plug. Look on the wall transformer for the Explorer and see what the voltage output and amps are, then compare that to the GT's wall transformer.

 

[Md Epidemic]

Explorer wall transformer Output: 15V DC 100 mA

I'm sure, I read somewhere that they were the same that is why I used it.

 

[Critterhunter]

I think (?) the GT wall transformer is 50MA output and thus takes 20 hours to charge a dead 1000ma pack. The voltage sounds right (haven't looked on my GT transformer...but that's probably right for a 10 cell pack as the voltage has to be a bit higher than the pack will charge to) and it amp output shouldn't matter as the charger should only draw the current it needs and won't be forced to take any more than that. That's why you can put higher MA rechargeables in something that used lower capacity ones. The device only draws the current it needs and not any more, so the charge circuit should be fine with it.

Now, it's different when talking about the amp charge rate setting output FROM a charger. Increasing that on the charger it's self will of course cause a pack to charge faster, but we are talking about a power supply here to a charger...And in that case the charger only draws what it needs. Think of it this way....You could have a car battery the size of a house hooked up to your car to start it. So long as the voltage is the same (12V) it doesn't matter if the battery has a 100 amp capacity or 100 times that amount...The car starter will only draw the same amount of amps it needs to run. But, as said, the OUTPUT amp setting on some chargers can be changed and that will affect how fast current is being forced into the battery...But in the case of the wall transformer it's only acting as a power supply for the charge circuit so it shouldn't change a thing. The charge circuit will only draw what it's designed to.

 

[Rick(ND)]

The Charger for the Elite/GT and the Explorers and E-Trac are the same charger with the same part number, the older Sovereigns had a different plug on them and were only 50Ma. The charger used on the newer Elite,and GT are 100 Ma.
Another thing these are Nickle metal hydride's batteries that are being used and they have to be woke up by charging, then discharging to a safe level, then discharging and recharging again, so the first few charges will not last that long, but the more you use it the longer it will last to a certain point. I have a older Sun Ray SR-12 charger that does this as it will charge the battery and go to a pulse trickle charge when fully recharged, then I can push a button and it will then discharge it to a safe level and recharge it again. Now all the new Explorers/E Trac and the GT I sell I do this to them all so from day one they will hold a full charge when the customer uses them.
Another thing never ever run a rechargeable completely dead as it will ruin the battery or shorten the life of it and even change polarity of the cells. It is better to charge slower too as when charging at a higher rate the cells do get hot and will shortened the life of them.
Just recharge your battery and use it until the low battery alert, the recharge it again and it should last a little longer next time and even longer the next time. Give it a try and let us know if that don't do the trick.

Rick

 

[Md Epidemic]

Thanks for all the info. I will let you know how it works out.

Epi

 

[Critterhunter]

There are two camps in nicad/nimh care. I've done exenstive reading on this due to my RC electric plane hobby where battery care is of prime importance. One camp feels you should never completely drain a pack dead, while the other camp feels this is the best way to improve the run time of the battery by excercising it fully via draining it completely dead. I fall into that camp and will do this to my packs two or three times a year. Yes, there is the issue of the cells risking reversing polarity by draining them all the way dead...But most of what I've read on that says it's only a real risk if you let the pack sit drained dead for months on end.

Nimhs and nicads build up crystals over time in them that cause resistance and don't allow the pack to charge properly or hold as high of capacity as they should. By "shock" charging them at say 1 to 5 amps (be VERY careful doing this!) it will break down those crystals and restore the pack to proper function. It only needs to be done once, and then the pack should be drained and slow charged as normal.

 

[Rick(ND)]

I guess this is where actual experience comes to play again as I have tried different ways of charging and seen some batteries ruined because not charged properly. My son used to run RV cars and they used a c cell battery pack and could charge them up fast as they were made for it, but the life expediency wasn't that good. I bought a couple of times a bulk of some great 2600 Nimh batteries for my own use and for my Friends with the Explorers and they worked great, but those that was using a higher Mha chargers didn't seem to last that long like those using a smaller charger. I have a solar light bird feeder in the back yard for the last 3 years that still works as good now as it did when I started using them while the batteries I used a 1000MHa charger with only lasted less then a year.in a fast charger I had used. Had a 9 volt battery actually explode using a higher Mha charger as they have to be slowed charged as I learned from Experience. I have had great luck with the old Sun Ray SR 12 charger and never ruin a battery yet. I have tried several different chargers and found the ones that charge between 100 Mha and around 350 do the best. The Sun Ray SR 12 charges at around 350 and discharges around 450 if i remember right.
But as I have said before, What ever works for you and you are happy with go ahead and do that and learn from experience.
I see you and many others are curious about Minelab announcement as I am too, but being they are going about it the way they are i expect the cost to be higher as we are seeing higher priced detector coming out like the Deus. I don't feel it will be a gold detector as they have the best now, feel it will be a all purpose detector that will work for different thing, but I know one thing we will just have to wait and see ,and until then we can get our hopes up it that it will be something that will be a step forward in detecting like they did before with the Sovereigns first and then the Explorers and E-Tracs.

 

[Critterhunter]

Yes, just comes down to different people's experiences with battery care I guess. I do agree that the lower you charge a pack the better it's life will be. Fast charging in one hour will shorten the capacity and life of nimhs or nicads. There are some that are said to be built for fast charging but I've noticed the cycle life they claim isn't as long as a regular nimh that's slow charged. I only fast charge my nimhs at 1C (1 hour charge on a dead pack) here and there when I need them fast, or as said to break down crystals in them to recover a dead pack that won't charge or at least won't charge to full capacity. Recovered many nimh and nicad drill packs for friends that have sat for years dead by doing this. Their chargers wouldn't even recognize them let alone charge them, but the charger I have is advanced and I can force feed those buggers to bring them back to life. I usually blast charge them at 1 to 5C (1 to 5 times capacity), drain them, then slow charge them and drain them several more times doing it at a nice slow charge rate to fully condition them.

Of course I rarely mess with nimhs on detectors these days as it's lipos for me all the way. I do play with nimhs and nicads in my plane transmitters and other devices still, but even my planes run off lipos these days where as they too used to run off nimhs or nicads. Lipo technology is so much better. Lighter, faster charging (one hour charge time is perfectly healthy and fine for lipos), they won't self discharge sitting on the shelf like nimhs/nicads, and they hold their voltage very high until the very end of the discharge.

 

[Tin Fin]

Epi,

my NiMH batteries weren't lasting too long initially, but like Rick said, just use it, then recharge it, it will hold the charge longer next time; you do need to "wake them up" with that kind of use, or drain/recharge. I just use mine until the low battery alarm, swap out packs, and when I get home, charge the NiMH's, and have at it again the next day. I'm getting some pretty full hunts out of the NiMH's now, but at first, they didn't last real long.