rechargable battery failure

[bwireman]

Been using the energizer nickel-metal 2500ma batteries, that seem to fail immediately after charging.
This was a progressive problem starting with the charge dropping to 4 then 3 bars.
I use three sets of eight, two detectors and one spare set.
I started to notice that my detector were showing low charge
right after a charge cycle on all sets.
Found that at least one of eight had a low reading, about 1 volt.
I have grouped these into a separate set of four, and always charge them together.
These battery's probably have a different internal resistance,
making them charge less efficently than the others.
Well anyway, this has resolved my problem of being dead at the starting gate.
They all charge up to 1.39-1.4 volts, and last for up to maximum of
24 hours of use.
If you have just one or two battery's that are reading low isolate and charge separately.
Anyone using a charger should invest in a $5 - $10 meter to help resolve this type of a problem.
bwireman

 

[John-Edmonton]

Are you using the quick charge? The reason is that a quick charger does not always charge them up to full capacity, and decreases the life of batteries.

 

[Uncle Willy]

Forgot to ask, you're not mixing batteries in your charger are you?

Bill

 

[bwireman]

The 2500ma,all same type, energizer e squared type battery's uses a quick charge adaptor with slots for four cells.
The battery's were purchased from sam's club at different times, included 8aa and 4aaa cells per package.
The last purchase was over a year ago, due to the drop in service from the origional purchase.
Each detector, set of eight cells is charged together in two chargers.
Over a long period of time one or more cells begins to charge to a lower voltage. Measured with my fluke four digit multimeter, showing a degrade in individual cells.
The charger will switch off when three cells overcome the lower voltage of by averaging the parallel voltage of the four cells.
Removing the battery's from the charger and left sitting, the higher charged cells will drift back to the 1.4v range.
From experience, replacing the cells in the charger and immediately
turning the unit on will show a good charge.
Travel to a site to detect, and charge has already dropped to 3-4 bars.
This is why it is necessary to measure each cell after charging to determine if you have one that doesn't charge to its full capacity.
I have read where many other detectorist have complained about a failure of their battery's, and they simply replace them.
The cell's are probable still good, only needing to be charged by itself, or with other similiar cells.
I have not tried to verify if after charging separately, that the batteries can again be mixed with the others cells on the next charge.
But I have marked with a black marker on each cell that has given me a problem. 1= 1.1v 2= 1.15v 3= 1.15v 4= 1.05v
Charging these cells together, I measured 1.39-1.4v on all cells.
I don't pretend to know what caused this drop in voltage, but this is a simple work around.
I typically recharge the cells right after usage, and the next trip was ruined because of the low cell.
thanks
bwireman

 

[Neil in West Jersey]

I know that most detectors do not have a "discharge" feature, but your digital camera probably does.

My advice is to discharge your batteries before charging them. This will give a nice, even charge to your batteries, and will most likely give them a better charge overall due to the slight "memory" effect that rechargebles have. You should get the same charge as charging them individually.

 

[RAYAR]

[quote bwireman]Been using the energizer nickel-metal 2500ma batteries, that seem to fail immediately after charging.
This was a progressive problem starting with the charge dropping to 4 then 3 bars.

bwireman[/quote]

FWIW
I had two sets of four of those same batteries and they would not hold a charge for even a week. I did some research and came upon some info about these particular batteries. As far as I was able to determine, this only affected the 2500 mah Energizers. These batteries are manufactured in two different countries, Japan and China. The ones from Japan are also identified by the greenish coloured insulator around the positive post. The ones from China have a black insulator. The ones manufactured in Japan are the ones that have the problem holding a charge. I'm sure if you do a search for these batteries, you will be able to find some technical info on the cause for this problem.

I have noticed that most chargers that come packaged with these batteries have the ones manufactured in Japan. The country of manufacture is also printed on the batteries.

Hope this helps to pinpoint some of those charge retaining problems some of you are experiencing.

Ray

 

[stick]

check this out. i believe ray o vac has developed the same type of battery.

http://www.sanyo.co.jp/koho/hypertext4-eng/0511/1101-2e.html

 

[Uncle Willy]

The batteries I have last forever between charges. The palm-sized charger with four batteries only cost ten bucks. These batteries are supposed to last four times longer than an alkaline and they seem to do that quite well.

Bill

 

[moosbrth]

n/t

 

[moosbrth]

I do know this one fact about all the new rechargeable batteries, they come with rapid chargers, usually 1 hour now, the chargers cook the batteries. If you use the older 4-8 hour chargers, the batteries last a lot longer. The new chargers are great for the battery companies, bad for the user.

Tis a fact!

Thanks,

John