New Eneloops , what to do !! ?

Hey Guys ...

just got a Maha MH-C900 Charger with 16x Panasonic eneloop 4th gen 2100 cycles .

I assume first thing to do is discharge then break-in , right ?

Problem is i can't do break-in mode now ! , power goes out in Egypt like 4 times or more per day !!!!!!!!

So what should i do , discharge then charge & use the batteries normally & do break-in mode later ?

If the power goes out during break-in will i have to do it again ? also when discharging & charging ?

Power outage can harm the cells ?

Thanks

Hi there,imho just use them,thats how i have used mine issue free,top them up on charger then use

Use them straight from the pack,i think you will find no silly break in ideas on the blister.

I agree with ven and mcnair...Eneloops are good to go out of the box. Even if there is some small benefit to breaking them in, it isn't worth the effort, at least not to me.

A simple discharge then a charge and then i am good to go with new battery`s but watch out for missed or premature termination with new or old battery`s until they have been broken in a bit.

I am too impatient to do a full break-in, but the choice is yours.

John.

+1 on the previous 4 posts.

Pretty much what all the above posts say. You'll need a break-in on these specific batteries only to determine the capacity.

Thanks for replay guys
I did a discharge @100 Mah , & now chargint @500 Mah , everything is good ?

Use them out of the packet and then recharge them. I personally think the whole idea of break-in and conditioning is taking things too far and is out dated.

If you don't fully discharge your cells in normal use, then I would do a full discharge/charge cycle from time to time.

You have a good charger so just use them and don't fuss.

subwoofer said:

Use them out of the packet and then recharge them. I personally think the whole idea of break-in and conditioning is taking things too far and is out dated.

If you don't fully discharge your cells in normal use, then I would do a full discharge/charge cycle from time to time.

You have a good charger so just use them and don't fuss.

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I am with you,all this nonsense about multi meters and other such rubbish is really getting into geeky creepy stuff,still not read any instructions telling me to so therefore it is totally unnecessary.

Dr.444 said:

.. I did a discharge @100 Mah , & now chargint @500 Mah , everything is good ?

Click to expand...

For charging, Maha recommends no less than 0.5C, (to aid in delta-v eoc detection) which in the case of the standard AA Eneloops, would be about 1000mah. Fortunately, that is the default for the C9000, and you can merely insert the cells and walk away. If no buttons are pressed within 10 seconds, it will default to the 1000mah rate.

If you have a particularly bad day, Eneloops can take up to 1C, so you could increase that amperage up to 2000mah if you want, to get a charge finished between power outages.

IonicBond said:

For charging, Maha recommends no less than 0.5C, (to aid in delta-v eoc detection) which in the case of the standard AA Eneloops, would be about 1000mah. Fortunately, that is the default for the C9000, and you can merely insert the cells and walk away. If no buttons are pressed within 10 seconds, it will default to the 1000mah rate.

If you have a particularly bad day, Eneloops can take up to 1C, so you could increase that amperage up to 2000mah if you want, to get a charge finished between power outages.

Click to expand...

This seems excessive. I've certainly read about missed termination on AAs charged at only 200mA, but with 500mA being perfectly fine for AAs. I usually charge my AAs at 500mA or 750mA (with 700mA being the max that one of my chargers can output), to keep their temperature down. At 1000mA there is a noticeable increase in temperature.

NITECORE's new D4 charger if fully loaded charges at 350mA per channel, so from what you say this is in serious danger of missing termination. So far I've used the D4 to charge a lot of AAs, all of which have terminated perfectly. Maybe it is only the Maha charger that has this termination issue.

I don't have the C9000, but does it still default to 1A even with AAAs?

If you own a desktop computer in an area with such frequent power outages, it's worth getting an uninterruptible power supply (UPS) which you could connect your charger to. Not worth getting one just for your batteries though!
If the power goes out for long enough during a discharge, it would just reset and go into charge mode when the power comes back. No harm done.

I think the 0.5C-1C rule is probably from the days when smart chargers were still pretty dumb. Nowadays, they can detect very small -dV signals, and I've never had an issue charging Eneloops (or other NiMH brands) anywhere from 0.25C to 1C. (Up to 1C for Eneloops... other brands get too hot at that charge rate.)

If your charger isn't properly detecting a full AA battery at 500mA, it's probably better to just get a new charger. I wouldn't trust it at 1000mA either, if it doesn't work at 500mA.

Hello WalkIntoTheLight,

It is not a matter of detecting small signals. The reason for the 0.5 - 1.0C charge recommendation is that is works for a wide variety of cell conditions.

As cells age their internal resistance increases. When you pump charging current through a cell with higher internal resistance it heats up. When you transition from warm to hot you start doing damage to the cell.

The goal is to balance charge time and cell performance. You want to charge in a reasonable amount of time and want your cells to achieve the advertised amount of charge/discharge cycles.

After a bunch of testing another constraint is added. The end user doesn't want to spend more than $5 for the charger... Now the plot thickens.

You can get a charger that measures the internal resistance of cells and then charges accordingly. Unfortunately the "general" uses isn't interested in investing $200 - 300 in a charger.

The general findings are that with NiMh cells charging in the 0.5 - 1.0C range gives an easily detectable end of charge signal with new cells, cells that have been stored, and aged cells. It also can be done in a budget charger.

Along with this discussion we need to address the "useful" life of a cell. My definition is that when the cell drops below 80% of its initial capacity, it is time to recycle it. Others feel that as long as you can measure a voltage the cell must be good for something and they search to find a very low draw application to use it in. When a cell drops below around 80% of capacity it has higher internal resistance. This higher internal resistance causes the cell to heat up with higher currents (either from charging or loads). My inventory of cells all perform well and if anyone in the family grabs a cell they can expect good performance from it.

All chargers miss primary termination signals. They have back up methods to terminate the charge and unless you are monitoring the charge you are unaware of the missed termination.

There are a few "blacks" and "whites" in charging NiMh cells. The rest are all shades of gray. The recommendation to charge in the 0.5 - 1.0C range is a "lighter shade of gray..."

Tom

SilverFox said:

It is not a matter of detecting small signals. The reason for the 0.5 - 1.0C charge recommendation is that is works for a wide variety of cell conditions.

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Sure, but 0.25C works for an even greater variety of cell conditions. My point is that you don't have to charge at least 0.5C, less will do just as well if your charger is decent.

I have some very old AA NiMH cells (14 years old), that have high internal resistance but are still useful for low current devices. They don't like to be charged very quickly, because as you say they get too hot. So, I charge them at about 300mA, and if they're fully depleted they take about 6 hours to charge. That's less than 0.2C, and the charger still recognizes when they're fully charged. I'm pretty sure it's detecting the -dV signal, based on voltage measurements. If it's ever missed a detection, I'm not aware of it, and the cells all come off the charger at about 1.47v. Eneloops come off at a slightly higher voltage, so it's not doing a 1.47v termination like the C-9000 does.

If I charge them at 0.5C, they get too hot. So the 0.5C - 1C recommendation seems silly for these cells. It's a good general starting point for new cells, but you can charge slower and it will still work.

Hello WalkIntoTheLight,

I disagree.

I have had Eneloop and a wide variety of other cells miss termination at 0.25C...

In the days of NiMh cells being used in RC racing we tried multiple ways to maximize the performance and life of the battery packs we were using. 1C charging seemed to fit the "sweet spot" and provide good performance along with decent cycle life. When the shrink wrap melted off from the heat generated during 1C charging, the pack underperformed in use and was targeted for the recycle bin.

Congratulations on keeping your cells alive for 14 years. I just retired some that were 8 years old and I am hoping the Eneloop cells do a little better than that.

Tom

SilverFox said:

In the days of NiMh cells being used in RC racing we tried multiple ways to maximize the performance and life of the battery packs we were using. 1C charging seemed to fit the "sweet spot" and provide good performance along with decent cycle life. When the shrink wrap melted off from the heat generated during 1C charging, the pack underperformed in use and was targeted for the recycle bin.

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While I find 1C works okay with Eneloops, I still prefer to charge them much slower to avoid heat. My usual charge rate is about 500mA for them, which is 0.25C. I've never had a missed termination, and I'm pretty sure the charger just uses -dV to terminate.

If you're melting the shrink wrap, I think you're charging too fast! A slower charge might have doubled their life span or more. Though I understand for RC you're probably more interested in getting them charged quickly, so longevity isn't a concern.

Congratulations on keeping your cells alive for 14 years. I just retired some that were 8 years old and I am hoping the Eneloop cells do a little better than that.

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I have some 8 year old Eneloops cycled a couple of hundred times, and when I tested them at a 1C discharge rate, they were just as good as brand new gen 3 Eneloops (cycled just a few times). So I expect they'll continue to be strong for many more years.

The only NiMH cells I've been disappointed with are very high capacity ones. They seem designed for high capacity only when they're new, and within a couple of years are junk. I don't need high capacity, so I stick with regular Eneloops now.


P.S. Now that I think about it, I do recall missing termination a couple of times with those 14 year old cells that I charge very slowly. So, I guess charging too slowly does pose a risk. Still, if they're still going after 14 years, a few missed terminations from slow charging can't have done them too much harm.

Hello WalkIntoTheLight,

The intention wasn't to melt the shrink wrap. It just happened after the battery packs aged a lot...

Don't get me started on higher capacity cells. I had a set of Energizer 2300 mAh cells that developed a high rate of self discharge. I recycled them after less than a year. Their capacity was OK but if you didn't use them within a day or two of charging they were flat.

All I can say about the Eneloop cells is that they are remarkable. I got some of the first ones that made it into the US and they are still going strong. Simply remarkable.

Tom

SilverFox said:

Hello WalkIntoTheLight,

The intention wasn't to melt the shrink wrap. It just happened after the battery packs aged a lot...

Don't get me started on higher capacity cells. I had a set of Energizer 2300 mAh cells that developed a high rate of self discharge. I recycled them after less than a year. Their capacity was OK but if you didn't use them within a day or two of charging they were flat.

All I can say about the Eneloop cells is that they are remarkable. I got some of the first ones that made it into the US and they are still going strong. Simply remarkable.

Tom

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My first ever eneloop type were a brand called "Instants" purchased in/around 2005,still going strong with no issues and used in a high drain DAB radio on a daily basis together with various other household devices including led torches.