NMiH Battery Issues

Okay, so we are all using the NMiH batteries in our 950s, yes? I have some questions about these batteries. If you replay, please let us know whether you are stating facts or opinions, please. No alligators in the sewers unless you call it.

1. Should I be fully depleting the batteries before I put them in my MaHa MH-C204F charger and, if so, how should I do this? (I wrote Thomas Distributing about this and never heard back from them.)

2. I use two sets of batteries, with one in the camera and another charged and ready. I heard that NMiH batteries lose their power over time, beginning when they are removed from the charger--even though they aren't in use. Is this true? Does anyone have any data on this, such as how much is lost over what period of time?

3. Someplace (probably here) I read that the battery charge indicator on the 950 is designed for the alkaline batteries and doesn't reflect the actual charge state of NMiH batteries. I have noticed that it always shows full charge, and then suddenly drops way down to almost gone. Anybody have any data one this?

Quintessentially yerz,

Tyler Monson
Seattle, Washington

Tyler Monson said:

Okay, so we are all using the NMiH batteries in our 950s, yes? I have
some questions about these batteries. If you replay, please let us know
whether you are stating facts or opinions, please. No alligators in the
sewers unless you call it.

1. Should I be fully depleting the batteries before I put them in my
MaHa MH-C204F charger and, if so, how should I do this? (I wrote Thomas
Distributing about this and never heard back from them.)

Click to expand...

No, just put them in the charger. They are not fully charged from the factory. See the writing on the package. Nexcell tells you to charge it fully before using.

Unlike nicads, NiMH cells should not be stored empty or deep discharged. If you need to store them for a long time, fully charge them first.

Member said:

2. I use two sets of batteries, with one in the camera and another
charged and ready. I heard that NMiH batteries lose their power over
time, beginning when they are removed from the charger--even though they
aren't in use. Is this true? Does anyone have any data on this, such as
how much is lost over what period of time?

Click to expand...

Yes, they do self-discharge over time. I don't know the exact percentage. If I were to guess, 1%-2% per day. If you don't use a set for a while, put them on a charger for a few hours to top them off.

Member said:

3. Someplace (probably here) I read that the battery charge indicator on
the 950 is designed for the alkaline batteries and doesn't reflect the
actual charge state of NMiH batteries. I have noticed that it always
shows full charge, and then suddenly drops way down to almost gone.
Anybody have any data one this?

Click to expand...

Yes, this is true. The gauge is calibrated for alkalines. This is a fact stated by Nikon on their tech support site. You can search for it there http://www.nikontechusa.com .

Member said:

Quintessentially yerz,

Tyler Monson
Seattle, Washington

Click to expand...

Member said:

Member said:

1. Should I be fully depleting the batteries before I put them in my
MaHa MH-C204F charger and, if so, how should I do this? (I wrote Thomas
Distributing about this and never heard back from them.)

Click to expand...

No, just put them in the charger. They are not fully charged from the
factory. See the writing on the package. Nexcell tells you to charge it
fully before using.
Unlike nicads, NiMH cells should not be stored empty or deep discharged.
If you need to store them for a long time, fully charge them first.

Click to expand...

MK,

Sorry, perhaps I wasn't clear. I'm referring to ongoing charging, not the first pop. Say you use the one set for a couple of weeks in the camera and then wish to recharge them (top them off, so to speak). Should you first deplete the charge completely? I thought there was something about "battery memory" and that if you didn't discharge them completely, after a while they wouldn't have as long a live...or did this turn out to be another urban legend?

Tyler

I once read a statement from a battery company engineer that said that the memory effect in NiCd batteries was greatly overstated. He went on to warn that one should never completely discharge a battery - it will never be the same. The discharge cycle that some chargers will impose on NiCd batteries should not completely discharge the battery.

I am going to recharge my NiMH batteries after any extended use. I will try never to see the battery indicator read anything less than full charge. Well, that's my goal anyway. It's so hard to get facts on this sort of thing, I am just going to do it. Anyone know a battery engineer?

Curt, I know a very good battery engineer and I'm heavily into radio control racing so batteries are our lives. You are correct about the exaggerated effect of memory on nicads however it does exists. For nicads ONLY(!), you need to run them down every once in a while to "zap" the memory effect. All the chargers and racers in the R/C world drain their nicads first before recharging them. To make a long story short, some go to the extreme of draining them to a very low voltage and then dead shorting them until they are needed again! THIS IS ONLY FOR NICADS!

For NiMH you never try to run them down at anytime or you will shorten it's life. For the first generation NiMH you would kill them if you run them down. Always try to keep NiMH full.

Curt Austin said:

I once read a statement from a battery company engineer that said that
the memory effect in NiCd batteries was greatly overstated. He went on to
warn that one should never completely discharge a battery - it will never
be the same. The discharge cycle that some chargers will impose on NiCd
batteries should not completely discharge the battery.

I am going to recharge my NiMH batteries after any extended use. I will
try never to see the battery indicator read anything less than full
charge. Well, that's my goal anyway. It's so hard to get facts on this
sort of thing, I am just going to do it. Anyone know a battery engineer?

Click to expand...

Oops, sorry Tyler. What you said is not an urban legend but the truth. HOWEVER, it ONLY(!) applies to nicads and NOT NiMH cells. If topping off is need, just top it off. No need to drain it down first. That's the beauty of NiMHs.

See some of my comments to Curt below.

Tyler Monson said:

Member said:

Member said:

1. Should I be fully depleting the batteries before I put them in my
MaHa MH-C204F charger and, if so, how should I do this? (I wrote Thomas
Distributing about this and never heard back from them.)

Click to expand...

No, just put them in the charger. They are not fully charged from the
factory. See the writing on the package. Nexcell tells you to charge it
fully before using.
Unlike nicads, NiMH cells should not be stored empty or deep discharged.
If you need to store them for a long time, fully charge them first.

Click to expand...

MK,

Sorry, perhaps I wasn't clear. I'm referring to ongoing charging, not the
first pop. Say you use the one set for a couple of weeks in the camera
and then wish to recharge them (top them off, so to speak). Should you
first deplete the charge completely? I thought there was something about
"battery memory" and that if you didn't discharge them completely, after
a while they wouldn't have as long a live...or did this turn out to be
another urban legend?

Tyler

Click to expand...

Curt Austin said:

I once read a statement from a battery company engineer that said that
the memory effect in NiCd batteries was greatly overstated. He went on to
warn that one should never completely discharge a battery - it will never
be the same.

Click to expand...

SNIP

My experience is the opposite. I had a shaver that was supposed to get 45 minutes of use after a charge. After ten years where I completely discharged the battery after each use I was still getting 45-58 minutes after each charge. My son has gone through three shavers in the same time. He would plug his into the charger whenever it beeped and within two years had to plug it in to shave.

I've had the same experience with a battery powered drill. NiCd memory is no myth. Maybe the engineer had a vested interest in more batteries be sold?

If I was using NiCd batteries I would discharge them completely.

Roger

This goes back quite a way but it is still a very solid fact of life now as much as then.

MK virtually said it all - BELIEVE HIM, he's dead right. NiCads are so old-hat I wonder anybody bothers now that NiMH are here. I wouldn't agree that NiCads should be run RIGHT down sometime. Below a certain voltage level you may never get them up again. There is what is called a 'Delta' level to which they should go down then charge up from there.

The most important thing of all with batts - NiMH no differently - is that of this type (as oppopsed to such as wet cells) batteries should preferably always have a SLOW controlled charge. Never mind if it takes 16 hours or what to recharge them - have a spare set whilst the process is going on. If you FAST charge them (like some cheap chargers do in a couple of hours or so) you're just asking for trouble. The over-heavy charge will certainly bust the first batt in the chain of cells very quickly and you'll most likely finish up with hot batteries 'cos they're taking in too much current they can't absorb.

I believed in MAHA after reading about them and seeing the stuff on their site but they are completely unknown here in UK and after reading of your lack of response it appalls me that such a firm will fail to respond. Frankly I've lost interest and confidence in them now and have found another excellent 1500mA NiMH here which I am just charging up and about to put into use - hopefully with the success I expect. Remember, the CHARGER (controlled charge and slow) is just as important and if it IS a good charger it will go to 'trickle' when the batt is full and you can leave them connected up to 12 months so they don't lose anything while awaiting next use - thereby again keeping them 'up to scratch'.

Maybe after this time you will never read this but if you do I hope it is of use.

Eric

Tyler Monson said:

Okay, so we are all using the NMiH batteries in our 950s, yes? I have
some questions about these batteries. If you replay, please let us know
whether you are stating facts or opinions, please. No alligators in the
sewers unless you call it.

1. Should I be fully depleting the batteries before I put them in my
MaHa MH-C204F charger and, if so, how should I do this? (I wrote Thomas
Distributing about this and never heard back from them.)

2. I use two sets of batteries, with one in the camera and another
charged and ready. I heard that NMiH batteries lose their power over
time, beginning when they are removed from the charger--even though they
aren't in use. Is this true? Does anyone have any data on this, such as
how much is lost over what period of time?

3. Someplace (probably here) I read that the battery charge indicator on
the 950 is designed for the alkaline batteries and doesn't reflect the
actual charge state of NMiH batteries. I have noticed that it always
shows full charge, and then suddenly drops way down to almost gone.
Anybody have any data one this?

Quintessentially yerz,

Tyler Monson
Seattle, Washington

Click to expand...

MK, if what you say is true, thenwhy does the 204MK have a deep discharge cycle?
George

MK said:

For NiMH you never try to run them down at anytime or you will shorten
it's life. For the first generation NiMH you would kill them if you run
them down. Always try to keep NiMH full.

Curt Austin said:

I once read a statement from a battery company engineer that said that
the memory effect in NiCd batteries was greatly overstated. He went on to
warn that one should never completely discharge a battery - it will never
be the same. The discharge cycle that some chargers will impose on NiCd
batteries should not completely discharge the battery.

I am going to recharge my NiMH batteries after any extended use. I will
try never to see the battery indicator read anything less than full
charge. Well, that's my goal anyway. It's so hard to get facts on this
sort of thing, I am just going to do it. Anyone know a battery engineer?

Click to expand...

Click to expand...

I don't know what the 204MK charger is. Is that the Maha one that everyone raves about? I don't know why it has a deep discharge cycle. Maybe it's a dual charger for both nicads and NiMH? Only nicads should be deeply discharged every once in a while to maintain capacity.

George said:

MK said:

For NiMH you never try to run them down at anytime or you will shorten
it's life. For the first generation NiMH you would kill them if you run
them down. Always try to keep NiMH full.

Curt Austin said:

I once read a statement from a battery company engineer that said that
the memory effect in NiCd batteries was greatly overstated. He went on to
warn that one should never completely discharge a battery - it will never
be the same. The discharge cycle that some chargers will impose on NiCd
batteries should not completely discharge the battery.

I am going to recharge my NiMH batteries after any extended use. I will
try never to see the battery indicator read anything less than full
charge. Well, that's my goal anyway. It's so hard to get facts on this
sort of thing, I am just going to do it. Anyone know a battery engineer?

Click to expand...

Click to expand...

Click to expand...

here's a link that will explain NiMH technology beyond what you wanted:

http://data.energizer.com/batteryinfo/application_manuals/nickel_metal_hydride.htm

Tyler Monson said:

Okay, so we are all using the NMiH batteries in our 950s, yes? I have
some questions about these batteries. If you replay, please let us know
whether you are stating facts or opinions, please. No alligators in the
sewers unless you call it.

1. Should I be fully depleting the batteries before I put them in my
MaHa MH-C204F charger and, if so, how should I do this? (I wrote Thomas
Distributing about this and never heard back from them.)

2. I use two sets of batteries, with one in the camera and another
charged and ready. I heard that NMiH batteries lose their power over
time, beginning when they are removed from the charger--even though they
aren't in use. Is this true? Does anyone have any data on this, such as
how much is lost over what period of time?

3. Someplace (probably here) I read that the battery charge indicator on
the 950 is designed for the alkaline batteries and doesn't reflect the
actual charge state of NMiH batteries. I have noticed that it always
shows full charge, and then suddenly drops way down to almost gone.
Anybody have any data one this?

Quintessentially yerz,

Tyler Monson
Seattle, Washington

Click to expand...

MK,

Your assumption is correct. It is a dual chager.

-WJ

MK said:

George said:

MK said:

For NiMH you never try to run them down at anytime or you will shorten
it's life. For the first generation NiMH you would kill them if you run
them down. Always try to keep NiMH full.

Curt Austin said:

I once read a statement from a battery company engineer that said that
the memory effect in NiCd batteries was greatly overstated. He went on to
warn that one should never completely discharge a battery - it will never
be the same. The discharge cycle that some chargers will impose on NiCd
batteries should not completely discharge the battery.

I am going to recharge my NiMH batteries after any extended use. I will
try never to see the battery indicator read anything less than full
charge. Well, that's my goal anyway. It's so hard to get facts on this
sort of thing, I am just going to do it. Anyone know a battery engineer?

Click to expand...

Click to expand...

Click to expand...

Click to expand...

Roger is correct. I had a Black & Decker dust buster which was permanently hooked to a wall wart charger. After sitting for weeks, plugged in charging constantly it would run about 20 seconds and die. You MUST run NI-Cads down to zero to maintain that zero condition. If you cheat and plug it in whenever the "charge" light/lcd comes on in your razor, for instance, you'll continually raise the zero level, which means it will no longer be able to run down to the original zero level.

RG

Roger Vaught said:

Curt Austin said:

I once read a statement from a battery company engineer that said that
the memory effect in NiCd batteries was greatly overstated. He went on to
warn that one should never completely discharge a battery - it will never
be the same.

Click to expand...

SNIP

My experience is the opposite. I had a shaver that was supposed to get
45 minutes of use after a charge. After ten years where I completely
discharged the battery after each use I was still getting 45-58 minutes
after each charge. My son has gone through three shavers in the same
time. He would plug his into the charger whenever it beeped and within
two years had to plug it in to shave.

I've had the same experience with a battery powered drill. NiCd memory
is no myth. Maybe the engineer had a vested interest in more batteries be
sold?

If I was using NiCd batteries I would discharge them completely.

Roger

Click to expand...