Eneloop Self Discharge study

[UnknownVT]

I placed some Eneloop cells in a CD player I have. It does not have a clock. When it is shut off, the display is blank.
I just tried to play a CD in it after 6 months of storage and found the batteries completely discharged.
I am now storing the batteries separate from the player and not installed.

Ha-ha! this has just happened to me.....

I bought a second MP3 player about 3.5 months ago with better capacity and longer playing time than the first one I had (both use a single AAA).

So about that time I used the second one much more, to the point where I just put an eneloop AAA in to the first to keep it "ready" - today I tried to play the first MP3 player, and I was dismayed to find it would not power on - changing the battery - it worked - so I checked the voltage of the eneloop AAA - down to about 0.55Volts - ouch! - it's on charge now, and I have noted its number - hopefully it is not badly damaged.

Although this could possibily have damaged the eneloop - think what may have happened if I kept an alkaline in it (which I was tempted to do ) it probably would have leaked and damaged the player.......

Like you - I am now going to keep that MP3 player "unloaded" until I need to use it.......

 

[Mike86]

I found this forum while trying to find information on eneloop batteries. Specifically why the instructions state not to plug the charger in upside down or it will finish charging before it is fully charged. I've never heard of such a thing & did email Sanyo several times asking why. I finally received a reply stating:

"The batteries contain electrolytes in liquid form. If they are charged any other way than upright, it is possible that you will not get a 100% charge every time. No damage will be done to the batteries, only the fact that you could possibly find yourself charging them more than what is necessary...which, in turn, will decrease the overall life of the cells."

While waiting for their reply, I previously thought I saw something about possible electrolyte pooling in another thread, but can't locate it at the moment. I'm curious if anyone has found any difference in the charging position of the batteries. IOW, is this really critical in charging the cells to their maximum capacity? Are the forum members here actually keeping the batteries upright when charging? Or is Sanyo just being too critical? Is the eneloop electrolyte any more "liquidy" than other NiMH's electrolyte? Since my wall outlets are sideways I have used an extension cord in order to keep the charger positioned upright.

Obviously I want maximum capacity, but am I being too concerned about nothing?

 

[TorchBoy]

:welcome: Mike86.

"The batteries contain electrolytes in liquid form. If they are charged any other way than upright, it is possible that you will not get a 100% charge every time. ..."

My crapometer has just been triggered.

I'd be more inclined to believe a heat-related explanation.

 

[SilverFox]

Hello Mike,

Welcome to CPF.

You may find this thread informative.

Tom

 

[LuxLuthor]

:welcome: Mike86.


My crapometer has just been triggered.

Link added

 

[Bones]

:welcome: Mike86.

My crapometer has just been triggered.

Link added

One of our crapometers must need recalibration, mine is pegging right off the scale at the nonsensical response that Mike86 received from Sanyo's representative.

Must have graduated very near the top of his/her creative writing class ...

 

[TorchBoy]

Link added

:laughing: Brilliant. I've bookmarked it for future reference.

 

[Mike86]

Thanks for all the replies.

I never heard of battery position affecting charging capacity. When the NC-MQN05U instructions mentioned this I became curious & went to the Sanyo eneloop web site. They did not list this charger, but had 2 others and both of those instructions said the same thing about not charging upside down. So I started searching for answers & emailed Sanyo several times & finally got a response.

Just for the heck of it I should ask Sanyo if capacity is also reduced if used upside down!

If buying the eneloop cells by themselves is there any mention in the packaging regarding the charging position? Another thread mentioned the MQN06 had a temp sensor at the bottom. Perhaps the MQN05 also has one at the bottom & the upright charging "caution" is really about the charger & not about the batteries.

Curious Mike

 

[Black Rose]

My NC-MDR02N Eneloop charger also says not to plug in upside down, or it may finish charging before the cells are fully charged.

The packaging for the 2 pack and 4 pack of Eneloops I purchased make no mention of the charging position.

 

[Mike86]

Your crapometer is going to break now.

I just had to contact Sanyo again. I asked about the electrolyte, about discharging upside down, and about the separately packaged eneloops that made no mention of charging right side up. Here is their response:


The batteries your friend bought wouldn't have the
instruction to position the charger upright because he
bought the batteries separately. It still implies to when he
charges his batteries in another charger. I do not know
about other brand of chargers, but it is likely they all say
the same thing on their instructions about the batteries not
fully charging to their full potential. In regards to your
camera, it will not do any harm or discharge them
differently to the batteries because they aren't charging in
your camera.

Best Regards,

Customer Service
Sanyo Energy (U.S.A.) Corp.
http://www.eneloop.com
http;//www.sanyobatteries.com

 

[45/70]

Looks like, possibly...... just possibly, there may be a job opening at Sanyo USA's customer service department..... soon!

Dave

 

[Bones]

Your crapometer is going to break now.
...

If the cells should to be upright to charge, then wouldn't the same thing apply when they are discharged?

Perhaps you will find that your camera will take fewer shots when repeatedly used in positions other than upright.

Or would the opposite apply, and the cells should be positioned upside down when being 'drained' of their energy?

I'm so confused ...

 

[Mr Happy]

If you examine a rechargeable battery carefully, you will notice little vent holes around the top near the button.

When you charge the battery you must keep it upright or some of the charge will escape out of these vent holes and get lost.

This doesn't matter so much when the battery is being used after charging, because by that point the charge has been soaked up in the electrolyte like a sponge and it can't escape so easily.

 

[45/70]

Correct me if I'm wrong Mr H, but I believe if the vent holes actually "vent", you loose electrolyte regardless of the cells position.

As far as why the instructions say to keep the charger upright? As someone has already stated, there is a thermal sensor in the bottom of the unit. Plug it in upright, no problem. Upside down, heat rises. To where? Ah, you guessed it! The thermal sensor! It says to itself, "Boy! These cells are getting way to hot! Let's shut'er down!"

Have you ever heard of making moutains out of molehills? :naughty:

Dave

 

[Mr Happy]

Correct me if I'm wrong Mr H, but I believe if the vent holes actually "vent", you loose electrolyte regardless of the cells position.

Ah, but, it's those electrons, you see. They are very tiny and they can escape out of the vent holes and evaporate without any visible sign of leakage.

 

[45/70]

Ah, but, it's those electrons, you see. They are very tiny and they can escape out of the vent holes and evaporate without any visible sign of leakage.

Please, do tell me more about electron evaporation. For example, at what temperature (F,C, or K) do these bad boys evaporate?

Sorry, OT. I'll stop now. :devil:

Dave

 

[Black Rose]

Not sure which is more funny, the Sanyo comments or the resultant conversation :laughing:

 

[TorchBoy]

Strangely enough, my father has recently noticed that his GP 2 hour charger terminates much more reliably when it's vertical. When he plugs it into a distribution board on the floor (so the charger is flat) he says it repeatedly overcharges the cells and they end up stinking hot (metaphorically) for a long time. I presume this implies there's a thermal sensor in the top of the unit.

 

[Bones]

...
I finally received a reply stating:

"The batteries contain electrolytes in liquid form. If they are charged any other way than upright, it is possible that you will not get a 100% charge every time.
...

There is also this conundrum; SilverFox conducted a little experiment in this regard, and actually noted a fairly significant capacity increase compared to when the same cells were charged upright:

...
The results from charging them [upright] in the Eneloop charger:

1890
1918
1928
1893

...
I was also wondering what would happen if you charged with the unit plugged in upside down.

In my case, it seems to do a better job of charging.

Same Eneloop cells with the charger plugged in upside down gave me

1987
1999
1984
1992

Keep in mind that Your Mileage May Vary...

How do you suppose Sanyo would react if a whole bunch of us insisted that our chargers and Eneloops be replaced as faulty if they too deliver more capacity when charged upside down?

I can imagine the conversation should word of this reach the boardroom:

"Are you telling us that our customers are returning a flagship rechargeable products in droves because they're delivering to much capacity!"

 

[Mike86]

If the cells should to be upright to charge, then wouldn't the same thing apply when they are discharged?

Perhaps you will find that your camera will take fewer shots when repeatedly used in positions other than upright.

Or would the opposite apply, and the cells should be positioned upside down when being 'drained' of their energy?

I'm so confused ...

I'm confused too.

When I asked if the charging position is critical due to the electrolyte, I would think the discharge position would also be critical. I also said that my camera uses 4 AA cells, two upright & two upside down. Does this mean they are going to discharge differently?

Somehow I feel compelled to joust with those Sanyo reps. I guess I have too much time on my hands right now.