Are all of the extra 'features' necessary? (la crosse bc-700 vs nitecore i4?)

47 posts / 0 new
Last post

Pages

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47
Are all of the extra 'features' necessary? (la crosse bc-700 vs nitecore i4?)

I know there are tons of posts talking about the features of all of these chargers, but I feel like I get lost reading through all of the reviews. after reading a bunch of horror stories about using primaries, I have decided to replace a lot of my edc cr123 lights with nimh AA/AAA lights. I have tons of cr123 lights but will be saving these for backup lights, car lights, etc due to the lithium primaries’ shelf lives.

anyways, I have invested in 24 eneloop AAs to get started but they came with a crappy charger, so I went ahead and bought the nitecore i4 charger from FT which should be here tomorrow. my other chargers are my xtar wp2 and a wp6 for my 18650s and I have been quite happy with them. I have a fluke dmm and regularly check cell voltages, etc. my question is, i have been reading more about these advanced chargers with their break-in cycles, refresh cycles, discharge cycles, different charging rates, etc…and it seems as if it would make a pretty big difference. especially only being ~$15 more than the i4 charger. is it worth it to go ahead and get the nice charger, or will the i4 be all I need in the long run for nimh cells? I realize the i4 will take longer to charge..and I have backup cells so that’s no big deal. I am mainly trying to prolong the life of my batteries as much as I can…just not sure if the payoff is worth it

Bort
Bort's picture
Offline
Last seen: 5 hours 36 min ago
Joined: 06/01/2012 - 17:15
Posts: 8534
Location: Holding the proverbial flashlight

breakin is unnecessary, i like having the display because of the information it gives out, but eneloops are solid batteires that can take a lot of abuse and keep on ticking, and if i remember correctly the i4 is not a dumb nimh charger so just use it when needed and don’t worry about the batteries, in 5 years they will still work great, and in 10 years may be needing replacement (or could still be perfectly fine depending on how you treated them and how much they were used)

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47

thanks bort. that’s kind of what I figured I’m sure i will end up getting one sooner or later but may put it off for a bit. even if I kill eneloops every 5 years that’s not too bad. I have also been looking at the zts battery testers (more for my li-lion / primary cells) just to keep an eye on things. I haven’t read much about them on these forums though so not sure what to think

Chloe
Chloe's picture
Offline
Last seen: 5 years 6 months ago
Joined: 01/30/2013 - 14:14
Posts: 4595
Location: 联合王国

I was going to get an i4 for my growing eneloop collection, but in the end went for an Angeleyes charger because I read that it’s best to discharge NiMH completely before charging, and the Angeleyes has a discharge mode (the display also shows more info).

Refresh mode is simply two modes combined (discharge fully then recharge to full).

The instructions in my Angeleyes explains:

Quote:
The function of Refresh is basically used for eliminating the “memory effect”. For NiMH it is not necessary to use Refresh mode every time the battery is charged. It is recommended that Refresh is used after every 20-30 times charge, or the battery capacity obviously decreases.

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47

oh wow I haven’t heard about that one. it’s almost the same price but has all of the displays and a cool color! That might be the one. thanks Chloe! I know bort said break-in isn’t very important but what exactly does it do?

Chloe
Chloe's picture
Offline
Last seen: 5 years 6 months ago
Joined: 01/30/2013 - 14:14
Posts: 4595
Location: 联合王国

I have no idea about break-in, but at a guess maybe for some batteries it is necessary to discharge and recharge ~10 times to achieve full capacity?

Eneloops are designed to be used out of the pack, so I use them as such. Smile
I think if I wanted to babysit my batteries I would have chosen lithium rechargeables! :bigsmile:

mhanlen
mhanlen's picture
Offline
Last seen: 1 month 1 week ago
Joined: 03/01/2013 - 11:42
Posts: 2601
Location: Eastern USA

Going from dumb wall chargers to a smart AA/AAA charger that has a refresh and test modes, as well as discharge and charge- well it’s awesome. It tells you how good or bad your batteries are, so you can keep track of them over time. I think the test and refresh are really great tools- If it was a choice between saving $15 or getting a charger with the LCD/capacity readout, I’d go with the latter rather than saving the money personally.

On the other hand the i4 consolidates the amount of chargers you have laying around if you also have Li-ions.

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47

yeah my initial though was to just buy the nice charger and ‘gift’ one of the old ones to a buddy..but they’re all so nice! i would give the wp2 away, but it’s my only one that has usb charging capabilities. then the wp6…well it charges 6 at once! the nitecore will be my only charger that will handle so many types of cells. i may just have to get another one and keep them all! whew this site is trouble :~

Chloe
Chloe's picture
Offline
Last seen: 5 years 6 months ago
Joined: 01/30/2013 - 14:14
Posts: 4595
Location: 联合王国

Well, I don’t think you necessarily need to buy a new charger. If you know to discharge fully once in a while, the i4 should be fine.

The Angeleyes also has temperature monitor as well as checking the voltage, which is nice for peace of mind. I only ran into this with my dumb Uniross wall charger that works by timer (!!!) and the cells got too hot as a result.

I do still want a little USB charger for my eneloops (like this little Sanyo), because it will be handy when traveling.

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45

Keep in mind: the I4 also charges lithium-ion cells. That’s a BIG plus.
I have a Maha C-9000 for NIMH and a I4 for lithium.
When i travel, i only take the I4, as it can charge both kind of chemistries.

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45

WARNING!
I had that angeleyes charger.
It almost always overheated my NIMH cells! Stay away from it! And was very inconsistent with the charges.

If you want the BEST NIMH charger, go for the MAHA MH-C9000

Chloe
Chloe's picture
Offline
Last seen: 5 years 6 months ago
Joined: 01/30/2013 - 14:14
Posts: 4595
Location: 联合王国
ltcdata wrote:
WARNING! I had that angeleyes charger. It almost always overheated my NIMH cells! Stay away from it! And was very inconsistent with the charges.

Maybe yours was faulty? What type of batteries were you charging?

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45
Chloe wrote:
ltcdata wrote:
WARNING! I had that angeleyes charger. It almost always overheated my NIMH cells! Stay away from it! And was very inconsistent with the charges.

Maybe yours was faulty? What type of batteries were you charging?

I exchanged it two times. Maybe the batch that went to my country had a lot of faulty units.
NIMH batteries, eneloops. With my maha charger at 1Ah rate, they get only slighty warm.

Remember: the best charge rate for NIMH batteries is 0.5C to 1C.

A good charger must have dv/dt, Tº and timer for termination.

The angeleyes seemed not to terminate correctly, hence, overheat.

Chloe
Chloe's picture
Offline
Last seen: 5 years 6 months ago
Joined: 01/30/2013 - 14:14
Posts: 4595
Location: 联合王国

ltcdata wrote:
I exchanged it two times. Maybe the batch that went to my country had a lot of faulty units.
NIMH batteries, eneloops. With my maha charger at 1Ah rate, they get only slighty warm.

Remember: the best charge rate for NIMH batteries is 0.5C to 1C.

A good charger must have dv/dt, Tº and timer for termination.

The angeleyes seemed not to terminate correctly, hence, overheat.

Wow that doesn’t sound good. Sad Do you know whether the “u30” displayed on boot is the software version?

Well, I have discharged and charged some eneloops with mine today (one AA and two AAA) and it seems to terminate properly. Cells were only a little warm. I also tried to charge three “known dead” AA Uniross and it flashed, same with a pair of Philips AAA I wasn’t sure about (eneloopy doesn’t like these two either, always red nose). I will keep an eye on my charger just in case.

Chidwack2
Offline
Last seen: 7 years 2 months ago
Joined: 03/16/2013 - 00:14
Posts: 326

I bought a MAHA C9000 and I have been very happy with it. I have also found that after the newness has worn off, I’m more and more interested in just getting the batteries charged. I just want to pop them in a charger and take them out when they are done. MAHA is adjustable for when you want to charge a little faster but I’m liking the simpleness of my inteli4.because it charges my LiOn batteries too. I have not heard that it is important to discharge MiMh batteries all the way down before recharging them. That is important with NiCad batteries because they have a memory.

I really don’t worry about my Enloops and how many times they will recharge anymore. By the time they wear out, I will probably be dead or batteries will have improved to the point that I will want new ones anyway.

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45

Chloe wrote:
ltcdata wrote:
I exchanged it two times. Maybe the batch that went to my country had a lot of faulty units.
NIMH batteries, eneloops. With my maha charger at 1Ah rate, they get only slighty warm.

Remember: the best charge rate for NIMH batteries is 0.5C to 1C.

A good charger must have dv/dt, Tº and timer for termination.

The angeleyes seemed not to terminate correctly, hence, overheat.

Wow that doesn’t sound good. Sad Do you know whether the “u30” displayed on boot is the software version?

Well, I have discharged and charged some eneloops with mine today (one AA and two AAA) and it seems to terminate properly. Cells were only a little warm. I also tried to charge three “known dead” AA Uniross and it flashed, same with a pair of Philips AAA I wasn’t sure about (eneloopy doesn’t like these two either, always red nose). I will keep an eye on my charger just in case.

If they’re a little warm, it’s perfect. If they are hot to touch, stop using the charger.
To confirm the charge current, you could use a multimeter.

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45

Chidwack2 wrote:
I bought a MAHA C9000 and I have been very happy with it. I have also found that after the newness has worn off, I’m more and more interested in just getting the batteries charged. I just want to pop them in a charger and take them out when they are done. MAHA is adjustable for when you want to charge a little faster but I’m liking the simpleness of my inteli4.because it charges my LiOn batteries too. I have not heard that it is important to discharge MiMh batteries all the way down before recharging them. That is important with NiCad batteries because they have a memory.

I really don’t worry about my Enloops and how many times they will recharge anymore. By the time they wear out, I will probably be dead or batteries will have improved to the point that I will want new ones anyway.

I have both, but the algorithm that the maha uses is better. The I4 uses a lower current (more time to charge the battery), and does not use a dt/dt algorithm so i wonder the end of charge detection is good. It seems good because the battery do not heat up, and checking the charge with the maha, it’s almost as good, but still, makes me wonder.

Also, if you charge AA eneloops, you just pop them and after 10 seconds the maha starts a 1Ah charge, perfect for 2100mAh eneloops. No buttons, just pop in the battery in the charger.

About the discharge of NiMH: Is good to do a full recycle every 20-30 cycles. Remember the rates: 2100mAh cell: 1000mAh charge, 500mAh discharge. 2 hours rest after charge and after discharge.

Don
Don's picture
Offline
Last seen: 1 year 3 months ago
Joined: 01/12/2010 - 16:32
Posts: 6617
Location: Scotland

I’ve not had any trouble from either of my Angeleyes. OK, they are less flexible than the Maha C9000 – but around here, the best price for a Maha would buy me three Angeleyes. And leave me enough for a (small) beer.

Mine have never overheated a cell – ever and I’ve had them for years.

I do remember reading somewhere that for 1G Eneloops (I have quite a lot of these) they should not be charged above 950mA. But I’ve never been able to find that again.

On finding them at Fasttech, I’ve got another one on its way to me just now.

Some of the C9000s have been known to have issues too.

But I’ve heard too many horror stories about LaCrosse chargers (mainly the BC-900 but I have heard such stories about the 700 too) to ever touch one. The Other Plaice used to have lots of discussion about these devices – if they haven’t lost it in one or other of their blowups.

 

The numbers from my light tests are always to be found here.

https://spreadsheets.google.com/ccc?key=0ApkFM37n_QnRdDU5MDNzOURjYllmZHI...

Bort
Bort's picture
Offline
Last seen: 5 hours 36 min ago
Joined: 06/01/2012 - 17:15
Posts: 8534
Location: Holding the proverbial flashlight

Some misinformation i’ve seen on this thread (correct me if i’m wrong with references please)
NiMH don’t have a memory effect (or if they do its negligible) and will last longer if charged as needed, fully discharging before charging has little capacity effect and uses up more cycles (out of the 500-1500 on the eneloops)
Charging above 0.5C also reduces longevity, they can be quick charged, but charging at 500ma or less will give the most charge cycles. (some non eneloop batteries i have won’t take over 200ma, they either terminate early or get too hot to hold even though they are less then 60% charged)

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

Chloe
Chloe's picture
Offline
Last seen: 5 years 6 months ago
Joined: 01/30/2013 - 14:14
Posts: 4595
Location: 联合王国

Hi Bort, the info I posted about refresh and break-in were taken from the manual that came with my Angeleyes charger.

What you said about charging non-eneloops is interesting. I have some Philips 750mAh AAA's that the Angeleyes does not want to charge, yet they hold some charge (enough to light a Tank007 TK-703) and can be charged with my old Uniross dumb wall charger, but this charger makes the batteries hot.

Since I have some dead Uniross NiMH¹ that have bubbled wrapping from repeated charging in the Uniross charger I don't believe heat is good for batteries. I was charging them almost every day since I used them with a digital camera.

1. I hope these won't explode or leak. I know I should throw them out but I want to dispose of them properly.

Bort
Bort's picture
Offline
Last seen: 5 hours 36 min ago
Joined: 06/01/2012 - 17:15
Posts: 8534
Location: Holding the proverbial flashlight

Chloe wrote:

Hi Bort, the info I posted about refresh and break-in were taken from the manual that came with my Angeleyes charger.

What you said about charging non-eneloops is interesting. I have some Philips 750mAh AAA’s that the Angeleyes does not want to charge, yet they hold some charge (enough to light a Tank007 TK-703) and can be charged with my old Uniross dumb wall charger, but this charger makes the batteries hot.

Since I have some dead Uniross NiMH¹ that have bubbled wrapping from repeated charging in the Uniross charger I don’t believe heat is good for batteries. I was charging them almost every day since I used them with a digital camera.

1. I hope these won’t explode or leak. I know I should throw them out but I want to dispose of them properly.


i’m guessing the fully discharge information was recycled from Nicad batteries
i have some duracell 2650 mah that terminate prematurely on charging at 500ma or higher, and a crummy rayovac model that heats up like an incandescent lightbulb if i try 500ma

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47

wow yeah thanks everyone for the info. I got my i4 today and compared to my crappy charger it is night and day already! I think I will stick with this for a while and research a bit more before I make a decision. but for new cells I would say the 375 ma per channel will be fine (and believe it or not, it’s a lot faster than the other charger I was using). as my cells get older i will definitely get a charger with more functions.

also, I was under the impression nimh was best to discharge all of the way before putting them back on the charger…but are you saying that topping the cells off early is better than draining and recharging? this is how I have been charging my li-ions and I from what i understand, 2 half charges on li-ions is about equal to 1 full charging cycle off of the batteries and is easier on them in the long run. plus it’s nice to keep them topped up. so is this okay to do with nimh as well?

Bort
Bort's picture
Offline
Last seen: 5 hours 36 min ago
Joined: 06/01/2012 - 17:15
Posts: 8534
Location: Holding the proverbial flashlight

lgr45 wrote:
wow yeah thanks everyone for the info. I got my i4 today and compared to my crappy charger it is night and day already! I think I will stick with this for a while and research a bit more before I make a decision. but for new cells I would say the 375 ma per channel will be fine (and believe it or not, it’s a lot faster than the other charger I was using). as my cells get older i will definitely get a charger with more functions.

also, I was under the impression nimh was best to discharge all of the way before putting them back on the charger…but are you saying that topping the cells off early is better than draining and recharging? this is how I have been charging my li-ions and I from what i understand, 2 half charges on li-ions is about equal to 1 full charging cycle off of the batteries and is easier on them in the long run. plus it’s nice to keep them topped up. so is this okay to do with nimh as well?


I keep my nimh fully charged, there is no data i know of that say this reduces their life
li ion on the other hand age faster when kept at full charge, 40% is supposed to be best for longevity, but from what i am told up to 80% is fine too

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47

yeah i just top up the few li-ions that I regularly use. the rest are kept around 3.7V. are nimhs alright to keep fully charged?

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45
Bort wrote:
Some misinformation i’ve seen on this thread (correct me if i’m wrong with references please) NiMH don’t have a memory effect (or if they do its negligible) and will last longer if charged as needed, fully discharging before charging has little capacity effect and uses up more cycles (out of the 500-1500 on the eneloops) Charging above 0.5C also reduces longevity, they can be quick charged, but charging at 500ma or less will give the most charge cycles. (some non eneloop batteries i have won’t take over 200ma, they either terminate early or get too hot to hold even though they are less then 60% charged)

If you keep the thermals down, charging at 1c does not harm at all. Check the engineering papers from Sanyo. Charging from 0.5c to 1c is the best way, if thermal is controlled and charge is terminated correctly. A 1c charge gives a very good termination voltage for end of charge detection.
If you charge at a lower rate (0.5c is the minimum!), the end of charge is harder to detect by the charger, and easier for the cell to be overcharged and damaged.
You could charge at 0.1c in a timed way from 16hs, but LSD cells like the eneloops are VERY sensitive to overcharge, so you must be very sure to play your cards there, ir you will damage the cells. If you want to do that way, charge them less than 16 hours. 14 hours for example.

BatteryUniversity.com page on nickel based batteries
about 3/4 down that page under
“ It is difficult, if not impossible, to slow-charge a nickel-metal-hydride. At a C rate of 0.1-0.3C, the voltage and temperature profiles fail to exhibit defined characteristics to measure the full charge state accurately and the charger must rely on a timer. Harmful overcharge can occur if a partially or fully charged battery is charged with a fixed timer. The same occurs if the battery has aged and can only hold 50 instead of 100% charge. Overcharge could occur even though the battery feels cool to the touch. “

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45
Chloe wrote:

Hi Bort, the info I posted about refresh and break-in were taken from the manual that came with my Angeleyes charger.

What you said about charging non-eneloops is interesting. I have some Philips 750mAh AAA’s that the Angeleyes does not want to charge, yet they hold some charge (enough to light a Tank007 TK-703) and can be charged with my old Uniross dumb wall charger, but this charger makes the batteries hot.

Since I have some dead Uniross NiMH¹ that have bubbled wrapping from repeated charging in the Uniross charger I don’t believe heat is good for batteries. I was charging them almost every day since I used them with a digital camera.

1. I hope these won’t explode or leak. I know I should throw them out but I want to dispose of them properly.

If you have 750mAh AAA, the maximum charge current for them is 375mAh. Higher, and you risk overheating and also damage the cells.
Heat is the CANCER for NIMH batteries. And for LSD batteries, is even worse.

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45
lgr45 wrote:
yeah i just top up the few li-ions that I regularly use. the rest are kept around 3.7V. are nimhs alright to keep fully charged?

From what iv’e read, nimh’s can be kept fully charged.
Li-Ions should be kept at 40-80%. Every 1 month is recommended to do a little discharge and charge to keep the cell healthy. Do not store in a place where the cells are exposed to heat. Also remember that li-ion cells age from the time they exit the manufacturing process. A never used 2 year old cell will have worse performance that a newer cell.

Bort
Bort's picture
Offline
Last seen: 5 hours 36 min ago
Joined: 06/01/2012 - 17:15
Posts: 8534
Location: Holding the proverbial flashlight
ltcdata wrote:
Bort wrote:
Some misinformation i’ve seen on this thread (correct me if i’m wrong with references please) NiMH don’t have a memory effect (or if they do its negligible) and will last longer if charged as needed, fully discharging before charging has little capacity effect and uses up more cycles (out of the 500-1500 on the eneloops) Charging above 0.5C also reduces longevity, they can be quick charged, but charging at 500ma or less will give the most charge cycles. (some non eneloop batteries i have won’t take over 200ma, they either terminate early or get too hot to hold even though they are less then 60% charged)

If you keep the thermals down, charging at 1c does not harm at all. Check the engineering papers from Sanyo. Charging from 0.5c to 1c is the best way, if thermal is controlled and charge is terminated correctly. A 1c charge gives a very good termination voltage for end of charge detection.
If you charge at a lower rate (0.5c is the minimum!), the end of charge is harder to detect by the charger, and easier for the cell to be overcharged and damaged.
You could charge at 0.1c in a timed way from 16hs, but LSD cells like the eneloops are VERY sensitive to overcharge, so you must be very sure to play your cards there, ir you will damage the cells. If you want to do that way, charge them less than 16 hours. 14 hours for example.

BatteryUniversity.com page on nickel based batteries
about 3/4 down that page under
“ It is difficult, if not impossible, to slow-charge a nickel-metal-hydride. At a C rate of 0.1-0.3C, the voltage and temperature profiles fail to exhibit defined characteristics to measure the full charge state accurately and the charger must rely on a timer. Harmful overcharge can occur if a partially or fully charged battery is charged with a fixed timer. The same occurs if the battery has aged and can only hold 50 instead of 100% charge. Overcharge could occur even though the battery feels cool to the touch. “

At 500ma charge my charger hasn’t failed to detect an eneloop charge end point. I gave 2 examples of batteries that can’t even take 0.25C. Most dumb chargers overcharge the batteries making them very hot, even many of the cheap eneloop chargers are not smart chargers yet are sold with the eneloops and when i had looked into them most were 500ma.
The bc700 does miss end points sometimes, but interestingly not on eneloops or duracell lsd, but on other lower quality batteries.
How do you control the temperature, fans, liquid cooling, dry ice? Is it worth it to charge faster and reduce life expectancy?

ltcdata wrote:
Heat is the CANCER for NIMH batteries. And for LSD batteries, is even worse.

source?

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

lgr45
Offline
Last seen: 8 years 2 months ago
Joined: 11/08/2012 - 14:11
Posts: 47

awesome thanks guys. lots of good info here! I think I need to spend some more time at the battery university site

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45
Bort wrote:
ltcdata wrote:
Bort wrote:
Some misinformation i’ve seen on this thread (correct me if i’m wrong with references please) NiMH don’t have a memory effect (or if they do its negligible) and will last longer if charged as needed, fully discharging before charging has little capacity effect and uses up more cycles (out of the 500-1500 on the eneloops) Charging above 0.5C also reduces longevity, they can be quick charged, but charging at 500ma or less will give the most charge cycles. (some non eneloop batteries i have won’t take over 200ma, they either terminate early or get too hot to hold even though they are less then 60% charged)

If you keep the thermals down, charging at 1c does not harm at all. Check the engineering papers from Sanyo. Charging from 0.5c to 1c is the best way, if thermal is controlled and charge is terminated correctly. A 1c charge gives a very good termination voltage for end of charge detection.
If you charge at a lower rate (0.5c is the minimum!), the end of charge is harder to detect by the charger, and easier for the cell to be overcharged and damaged.
You could charge at 0.1c in a timed way from 16hs, but LSD cells like the eneloops are VERY sensitive to overcharge, so you must be very sure to play your cards there, ir you will damage the cells. If you want to do that way, charge them less than 16 hours. 14 hours for example.

BatteryUniversity.com page on nickel based batteries
about 3/4 down that page under
“ It is difficult, if not impossible, to slow-charge a nickel-metal-hydride. At a C rate of 0.1-0.3C, the voltage and temperature profiles fail to exhibit defined characteristics to measure the full charge state accurately and the charger must rely on a timer. Harmful overcharge can occur if a partially or fully charged battery is charged with a fixed timer. The same occurs if the battery has aged and can only hold 50 instead of 100% charge. Overcharge could occur even though the battery feels cool to the touch. “

At 500ma charge my charger hasn’t failed to detect an eneloop charge end point. I gave 2 examples of batteries that can’t even take 0.25C. Most dumb chargers overcharge the batteries making them very hot, even many of the cheap eneloop chargers are not smart chargers yet are sold with the eneloops and when i had looked into them most were 500ma.
The bc700 does miss end points sometimes, but interestingly not on eneloops or duracell lsd, but on other lower quality batteries.
How do you control the temperature, fans, liquid cooling, dry ice? Is it worth it to charge faster and reduce life expectancy?

The eneloops chargers that came with the batteries are the perfect example of marketing over engineering. They are crappy chargers.
Most chargers that are being sold just use maxV+timer to end the charge. Very BAD.
To avoid overcharge and overheat is better to use a charger that uses all termination methods: dv/dt, maxV, thermal and timer.
To control temperature, my MH-C9000 has a temperature cut off, but i always put a little computer fan, just in case. Y preffer the maha over the lacrosse, but both are very good.

ltcdata
Offline
Last seen: 2 weeks 5 days ago
Joined: 03/06/2013 - 15:22
Posts: 45
Bort wrote:
ltcdata wrote:
Heat is the CANCER for NIMH batteries. And for LSD batteries, is even worse.
source?

I can’t remember the source Sad If i remember, i’ll post it right away.

Pages