Ni-MH Rechargeable batteries?

[Comage]

Does anybody here use such batteries? Can anybody give some advice on how to maximise the number of recharge cycles of Ni-MH batteries?

Are Ni-MH batteries really "memory effect" free?

[Imperion1]

Ni-MH batteries have 1000 recharge cycles. By the time you have recharged the batteries that many times, you'll probably have a couple of other sets. I know I do.

As for the "memory effect", as you call it, you can recharge the batteries at anytime. You don't have to wait for them to go completely dead. Like you would Ni-CD.

[Comage]

Okay, I was having some doubts when somebody told me Ni-MH batteries still suffer from a slight "memory effect".

And I read from a guide somewhere that to maximise the number of charge cycles of Ni-MH batteries, you should start to recharge the batteries when it's about 50% drained.

[Bovon]

From an advertisement for Olympus Cameras.


Ultra high capacity 2200mAh ( Average 2210 - 2230 mAH ) true minimum capacity means super long run time!
Last up to twice as long as ordinary rechargeable batteries.
Very High life curve. Can be recharged from 500 up to 1000 times!
Memory free operation means you can charge MAHA's POWEREX rechargeable batteries anytime you like.
Can be safely charged or rapid charged using any capable MAHA charger.
Excellent for power intensive devices like digital cameras, MP3 Players, Game Boy, CD Players, Global Position System, etc.
Can be used as a exact replacement for standard AA size batteries and NiCD rechargeable batteries in most all equipment and as with all our batteries are compatible with the Olympus Digital Cameras.

[leprechaun_40]

I have 2 sets of NiMh batteries for my digital cam. I keep one set in reserve so that when one goes dead, I have a charged set ready to go. I love them. They last considerably longer than ordinary batteries and seem to be much better than the NiCads ever were. Just make sure your charger can handle them, they do have somewhat different requirements than the NiCads.:t

[DMohler]

The only thing I would add is not to go cheap on a recharge unit.

[Comage]

Originally posted by DMohler
The only thing I would add is not to go cheap on a recharge unit.

Yes, I seriously agree to that statement. I own 2 kinds of GP chargers, a fast one and a slow one. The fast charger has a -dv function that cuts off the voltage to the charger when it detects that the battery is full. It takes around 2 hours to charge 2 x 1600maH batteries.

The slow one, is a big headache. It takes 16 hours to achieve full charge (regardless of 2 or 4 batteries). It doesn't have any special functions, it only has a timer that cuts off the current after 16 hours.

[Ammok]

I use NMH, only drawback is that they lose 3% of the charge per day and do not reach the 1.5v level you think they would, they actually only get to 1.3v which makes em useless for me digicam.:(

[cdroman]

Originally posted by leprechaun_40
I have 2 sets of NiMh batteries for my digital cam. I keep one set in reserve so that when one goes dead, I have a charged set ready to go. I love them. They last considerably longer than ordinary batteries and seem to be much better than the NiCads ever were. Just make sure your charger can handle them, they do have somewhat different requirements than the NiCads.:t

I totally agree. I have 2 sets for my dig. cam. , 2sets for each of our cordless optical mice and 2 sets for my kids tooth brushes. I also use them for our smoke detectors and remote controls.:t

[Billforce]

My Polaroid digital is known for eating batteries...regular Enercells were only lasting a week. I bought 4 NiMH batteries and a Panasonic charger and the batteries work well and even seem to hold a charge as long as regular Enercells.
The best thing about NiMH is you don't have to completely discharge before recharging because of the memory thing.

[rbt_coll]

ok here is how it is ...


these are good batteries

you MUST totally discharge these puppies at least once a month
and the memory effect is very real

here is how it works

you use the battery for say 3hrs a day for 7 days


and plug it in charge everynight over time it will only hold a charge for 6 1/2 to 7 max because it has LEARNED thats all thats required so in time thats all it will deliver

so no matter what you use let it run out and recharge it'll last longer



i'm in the field and have 10 yrs expierience so take my word for it



also these can have full charge for anyone with a muiltimeter(voltmeter)but as all of you know the discharge is very rapid .........IE ...full power ....++++6666666+++++++444+++222+++**** up



you know what i mean


Rob :t :t :eek: :( :)

[Ammok]

according to this specification, (http://www.nimhbattery.com/mh-4aa220.htm) there is no memeory effect.

[cdroman]

I got this off the web.

Do NiMH batteries have memory effect?

Technically, NiMH batteries do not have a "memory effect", but strictly speaking neither do NiCds. However NiMH batteries can experience voltage depletion, also called voltage depression, similar to that of NiCd batteries, but the effect is normally less noticeable. To completely eliminate the possibility of NiMH batteries suffering any voltage depletion effect manufacturers recommend an OCCASIONAL, complete discharge of NiMH batteries followed by a full recharge. NiMH batteries can also be damaged by overcharge and improper storage (see the NiCd section immediately above this one). Most users of NiMH batteries don't have to be concerned with this voltage depletion effect. But if you use a device say a flashlight, radio, or digital camera for only a short time every day and then charge the batteries every night, you will need to let the NiMH (or NiCd) batteries run down occasionally.

[Comage]

Originally posted by Ammok
I use NMH, only drawback is that they lose 3% of the charge per day and do not reach the 1.5v level you think they would, they actually only get to 1.3v which makes em useless for me digicam.:(

You have rechargeables that are "stated" as 1.5V? Mine states as 1.2V, but they work well for my discman and my gameboy advance.

Anyway, what actually constitutes to overcharging? Is trickle charging, overcharging? How much current should there be (technically speaking) to cause an overcharge? Or does overcharge means something else?

[comp_nut]

btw you can recharge ordinary batteries

you just have to take care,pay attention while charging

or they will spill

[Comage]

Hello there, thanks for the information. Personally, I see no point in charging ordinary batteries. The risk, for me, is far too big for me to take. :)

[Comage]

I've got another question: Let's say I've got a pair of Ni-MHs that I use as spares. If I leave them lying around, is it recommended that I leave them fully charged, or totally empty, so as to prolong the battery's charge cycles and battery life?

[cdroman]

I keep my spares fully charged. But if you have them laying around for long periods of time, they lose their charge. I've had no problems doing it this way and I've been using them since they became available.

[Comage]

I understand that a battery would lose it's charge when left lying around for long periods of time. Would a fully-charged battery left lying around have it's battery life affected, compared to an empty battery left lying around?

[cdroman]

I've had my spares for my digital camera that were fully charged sit around long enough to lose charge. I recharge them and they last as long as normal. As to whether this is shortening their lifespan in comparison to uncharged ones, I have no idea.

[Comage]

Sigh, does anybody around here have any idea on where I can find the truth? I guess it's no use e-mailing the battery company to ask for information. They'd most probably mask the truth and tell some falsified information to enhance the image of their products.