GarageBoy
Flashlight Enthusiast
Will this work alright or am I going to kill off the LSD feature on the batts? Thanks
Energizer 15 min charger with Sanyo Eneloops?
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Bones
Enlightened
Eneloop Facts and FAQs - FAQ 12:
Can I use a "Quick Charger" to charge an eneloop battery?
Though it is possible to charge an eneloop battery in a "Quick Charger", it is not recommended. We recommend charging eneloop batteries in a NiMh charger that is 2 hours or more. Charging eneloop batteries in a "Quick Charger" can reduce the overall life of the battery.
GarageBoy
Flashlight Enthusiast
Thanks, I'll stick with my Maha
WildChild
Flashlight Enthusiast
I use mine with the Eneloop with no problem but yes, a fast charger will kill the batteries sooner. It doesn't seems to kill the LSD feature...
SilverFox
Flashaholic
Hello GarageBoy,
That is a good question...
These cells are still too new to know how they will behave. I have charged the set that I use in my camera several times on a 15 minute charger, and they are still going strong. I don't use the 15 minute charger every time, but sometimes I am in a hurry. It has been over a year and a half now since I started using them, so 15 minute charging does not spell immediate death.
Tom
That is a good question...
These cells are still too new to know how they will behave. I have charged the set that I use in my camera several times on a 15 minute charger, and they are still going strong. I don't use the 15 minute charger every time, but sometimes I am in a hurry. It has been over a year and a half now since I started using them, so 15 minute charging does not spell immediate death.
Tom
matrixshaman
Flashlight Enthusiast
I put two of my AA Eneloops in a Rayovac Hybrid charger yesterday and was a bit concerned when I pulled them off the charger before going to bed. They had been on it for at least 5 or 6 hours and were still in 'Red light' mode indicating not fully charged yet. They were so hot when I pulled them I could barely hang on to them - at least it was uncomfortably hot. They read about 1.46 to 1.47 volts no load when I checked them. Unfortunately I don't have an Eneloop charger but I do have a better charger that will charge slow without overheating them. I'd say stick with a slower charger for better life if you can.
SilverFox
Flashaholic
Hello Bones,
I find the answer to question 12 very interesting...
If you go up the page a little and look at the data sheet for the battery, they list fast charging at 2 amps, but don't give any data for slower rates.
Sanyo bases their specifications on the JIS standard, which is a derivative of the IEC standard. Cycle life is based on slow charging, but there is a provision for accelerated cycle life testing based on a 1C charge. It would appear that the 1000 cycle life claim comes from testing done at slower charging rates.
I also find it interesting that they make a point of mentioning that you should use a Sanyo charger, implying that their chargers will do a better job of maintaining the batteries health. However, Sanyo also markets a 15 minute charger... Does this mean that if you use the Sanyo 15 minute charger you can still expect to get 1000 cycles from your Eneloop cells?
Could it be that marketing is putting a spin on things...?
In general, I would expect 15 minute charging to be harder on cells and this may effect cycle life. However, I have published tests showing the performance of normal 2000 mAh cells after 150 cycles on the 15 minute charger, and they were still going strong. I am sure they wouldn't last 1000 cycles, but they are only rated at 500 cycles, and I think there is a good possibility that they could reach that.
Sanyo may have implemented changes in their charging algorithms that allow accurate termination at slower rates. It may be time to put some of the Sanyo chargers under the same microscope that we put the Maha C-9000 under to see what is going on. One big difference will be that most people have recycled their "crap" cells, and it is harder to get a newer cell to malfunction or miss the end of charge termination.
Tom
I find the answer to question 12 very interesting...
If you go up the page a little and look at the data sheet for the battery, they list fast charging at 2 amps, but don't give any data for slower rates.
Sanyo bases their specifications on the JIS standard, which is a derivative of the IEC standard. Cycle life is based on slow charging, but there is a provision for accelerated cycle life testing based on a 1C charge. It would appear that the 1000 cycle life claim comes from testing done at slower charging rates.
I also find it interesting that they make a point of mentioning that you should use a Sanyo charger, implying that their chargers will do a better job of maintaining the batteries health. However, Sanyo also markets a 15 minute charger... Does this mean that if you use the Sanyo 15 minute charger you can still expect to get 1000 cycles from your Eneloop cells?
Could it be that marketing is putting a spin on things...?
In general, I would expect 15 minute charging to be harder on cells and this may effect cycle life. However, I have published tests showing the performance of normal 2000 mAh cells after 150 cycles on the 15 minute charger, and they were still going strong. I am sure they wouldn't last 1000 cycles, but they are only rated at 500 cycles, and I think there is a good possibility that they could reach that.
Sanyo may have implemented changes in their charging algorithms that allow accurate termination at slower rates. It may be time to put some of the Sanyo chargers under the same microscope that we put the Maha C-9000 under to see what is going on. One big difference will be that most people have recycled their "crap" cells, and it is harder to get a newer cell to malfunction or miss the end of charge termination.
Tom
GarageBoy
Flashlight Enthusiast
Will my Maha 801 on 1hr mode be okay? Or should I just use the 2hr mode?
SilverFox
Flashaholic
Hello GarageBoy,
Either the 1 hour or the 2 hour mode will work just fine.
Tom
Either the 1 hour or the 2 hour mode will work just fine.
Tom
johnny13oi
Enlightened
- Joined
- Feb 18, 2007
- Messages
- 642
The RayoVac Hybrid Charger is just a timer charger. It charges for 8 hours from the time you plug in the charger even if the batteries are full. This overcharges the batteries which is not good for them and will probably have bad side effects later on. I have 3 of those chargers and know how hot it makes the batteries.
I have both the Eneloop 4 position & 2 position chargers as well as the Energizer 15 min charger. I haven't and don't plan on using them in the 15 min charger. Luckily, I have enough extra Eneloop batteries on hand that I haven't found myself needing to fast charge them.
The FAQs page is interesting. #6 says that the four position needs to be charged in pairs. Do they have more than one model of 4 position? Because my instruction page that came with mine said that it can charge 1-4 at a time and doesn't mention charging in pairs. Mine was the charger/battery package sold at Wal-Mart. I have routinely charged single batteries with no ill effects. My understanding of chargers requiring pair charging is that the current applied is double the stated charge rate and then shared between the pair. If you would/could charge only one, wouldn't that mean that it would charge twice as quickly because it would be receiving twice the stated charge current? Anyway, mine takes an appropriate amount of time (given the stated charge current and level of discharge) no matter if I charge in pairs or as a single. Any thoughts on #6?
The FAQs page is interesting. #6 says that the four position needs to be charged in pairs. Do they have more than one model of 4 position? Because my instruction page that came with mine said that it can charge 1-4 at a time and doesn't mention charging in pairs. Mine was the charger/battery package sold at Wal-Mart. I have routinely charged single batteries with no ill effects. My understanding of chargers requiring pair charging is that the current applied is double the stated charge rate and then shared between the pair. If you would/could charge only one, wouldn't that mean that it would charge twice as quickly because it would be receiving twice the stated charge current? Anyway, mine takes an appropriate amount of time (given the stated charge current and level of discharge) no matter if I charge in pairs or as a single. Any thoughts on #6?
SilverFox
Flashaholic
Hello David,
I am not sure the marketing people talked to the engineering people before posting the FAQ page.
I sent them an email asking these same questions. I would suggest you do the same. As far as I know, both the 4 cell and 2 cell chargers bundled with the Eneloop cells are independent channel chargers. Sanyo does offer other chargers that charge in pairs, so perhaps this is a left over document from information on those chargers.
It will be interesting to see what, and if, Sanyo responds with.
Tom
I am not sure the marketing people talked to the engineering people before posting the FAQ page.
I sent them an email asking these same questions. I would suggest you do the same. As far as I know, both the 4 cell and 2 cell chargers bundled with the Eneloop cells are independent channel chargers. Sanyo does offer other chargers that charge in pairs, so perhaps this is a left over document from information on those chargers.
It will be interesting to see what, and if, Sanyo responds with.
Tom
Fallingwater
Flashlight Enthusiast
Anything that charges NiMH cells in less than an hour is not good for any battery, LSD or otherwise.
Bones
Enlightened
Hi Tom,
According to a post by prasinos and what little additional information I could find, the model MQN04 (4 cell) charger which is bundled with the Eneloop in Europe only has 2 channels:
http://www.candlepowerforums.com ... p=2148788
Casual Flashlight User
Flashlight Enthusiast
Well, you've just put me off buying one of these to fast charge my Eneloops! And as David D says...
I think I will just use the money to by another stack of Eneloops, which will eliminate the need for fast charging.
CFU
MrAl
Flashlight Enthusiast
Hi there,
Another idea is to use the Energizer 15 minute charger modification
technique i posted a while back on CPF. In this procedure, you
modify the charge slightly and then it takes 30 minutes to charge
instead of 15 minutes but it's much easier on the cells.
Tom did some tests a while back on 'regular' cells and found that the
number of cycles using a 15 minute charge is about 150, but then again
i dont know the number of cycles with the same cells when you use
a 2 hour charger to compare it with. I find that manufacturers always
tend to exaggerate the quality of 'their' cells so 1000 would seem too high.
Maybe 500 would be more typical.
The interesting thing is that the heating isnt that much different. The
fast chargers pump more current, but then again they detect the
end of charge faster too, so the cell is driven harder but for less time,
and heat and time are usually the detemining factors in the life of a part.
BTW, i can see by the graphs shown on that eneloop site that they
use the minus delta V technique with their charger, and that is pretty
much standard for chargers. The reason they dont want you to use other
chargers is because some chargers use other techniques that may not
be as favorable for the cells life, however any charger that uses the minus
delta V technique should be fine. Chargers that use temperature may
or may not be ok, depending on how high they let the temperature go.
Another idea is to use the Energizer 15 minute charger modification
technique i posted a while back on CPF. In this procedure, you
modify the charge slightly and then it takes 30 minutes to charge
instead of 15 minutes but it's much easier on the cells.
Tom did some tests a while back on 'regular' cells and found that the
number of cycles using a 15 minute charge is about 150, but then again
i dont know the number of cycles with the same cells when you use
a 2 hour charger to compare it with. I find that manufacturers always
tend to exaggerate the quality of 'their' cells so 1000 would seem too high.
Maybe 500 would be more typical.
The interesting thing is that the heating isnt that much different. The
fast chargers pump more current, but then again they detect the
end of charge faster too, so the cell is driven harder but for less time,
and heat and time are usually the detemining factors in the life of a part.
BTW, i can see by the graphs shown on that eneloop site that they
use the minus delta V technique with their charger, and that is pretty
much standard for chargers. The reason they dont want you to use other
chargers is because some chargers use other techniques that may not
be as favorable for the cells life, however any charger that uses the minus
delta V technique should be fine. Chargers that use temperature may
or may not be ok, depending on how high they let the temperature go.
For clarification, the 4-position bundled charger that was purchased at Wal-Mart that I mentioned in my earlier post, was bought in the USA. The model number is MQNO5U. Its input is only 100-120V; and has the fold away plug, a single charge indicating LED and the sliding cover. And I know from experience that it is not a simple timed charger. I don't know if this model is sold in Europe, nor do I know if the MQNO4 is sold in the USA.
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Fallingwater
Flashlight Enthusiast
...or just buy a 30 minute charger.
Again, though, the way I understand it is that anything higher than 1C will do some damage to the cells, and even 1C isn't ideal for long battery life.
This is doubly true for cheap offbrand cells, which might even leak if charged at too high a rate.
Ideally the cells should be charged with a 1/10C overnight charge, but since life's too short to wait for cells to finish charging a 1/2 to 1/3C charge will still be relatively kind to the cells without making you wait too long.
SilverFox
Flashaholic
Hello Fallingwater,
I am not sure where you are finding your information... but Sanyo (and other battery manufacturers) rate their cycle life using the accelerated cycle life test which involves charging at 1C.
I would think that if 1C charging was not good for battery life, they would rate them using a different charging current.
The ideal charge rate depends on the charge termination algorithm. When using negative delta voltage or delta temperature with respect to time, the ideal charge rate is 1C. You can mostly get away with dropping the charge rate down to 0.5C, but that is about as low as you want to go for those termination methods.
Slow charging is a great way to form a cell and wake it up after storage, but if used on a regular basis it robs the vibrancy of the cell and its performance becomes sluggish.
I am not sure what algorithm is used in the 15 minute chargers, but even with 15 minute charging you are good for around 150 cycles with high capacity cells and the 2000 mAh cells I tested were still going strong after 150 cycles on the 15 minute charger.
Tom
I am not sure where you are finding your information... but Sanyo (and other battery manufacturers) rate their cycle life using the accelerated cycle life test which involves charging at 1C.
I would think that if 1C charging was not good for battery life, they would rate them using a different charging current.
The ideal charge rate depends on the charge termination algorithm. When using negative delta voltage or delta temperature with respect to time, the ideal charge rate is 1C. You can mostly get away with dropping the charge rate down to 0.5C, but that is about as low as you want to go for those termination methods.
Slow charging is a great way to form a cell and wake it up after storage, but if used on a regular basis it robs the vibrancy of the cell and its performance becomes sluggish.
I am not sure what algorithm is used in the 15 minute chargers, but even with 15 minute charging you are good for around 150 cycles with high capacity cells and the 2000 mAh cells I tested were still going strong after 150 cycles on the 15 minute charger.
Tom
TorchBoy
Flashlight Enthusiast
Tom, what are the pros and cons of waiting for the two hour top-off charge on the MH-C9000?
Were they Eneloops?
