Few questions about rechargeable AA batteries

ric0chet06

Senior member
Jan 11, 2007
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recently I've been using a ton of AA batteries, from my battery eating camera to my xbox360 controllers. What kind should i get, and i notice some have different mv(millivolt)s. what kind should i get?
 

intogamer

Lifer
Dec 5, 2004
19,219
1
76
I believe Staples is clearance'ing Duracell Rechargeable equipment and batteries.

I would just stick with Duracell. I'm sure there are better chargers and brands. I know theres Ni-hD and Ni-CD?

Anyways I'm just posting to tell you about the deal :)
 

Doclife

Senior member
Oct 7, 2007
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I recommend that you get the low discharging NiMH rechargeable batteries. Basically, with the low discharging type, once you charged up the battery, the battery will retain about 85% of the charge after 1 year of storage (very convenience and ideal for use in TV/DVD remote controller). Regular NiMH rechargeable batteries will self discharge to 0% after a month or so, whether you use it or not.

The low discharging type I use is Eneloop, made by Sanyo.

http://thomasdistributing.com/...130dbb9c5e50d2bff55c21

The charger I use is the Maha 401FS with the 100-240VAC adapter. I like this charger because I have the option to charge the battery from 0 to full in 100min for emergency or the 5hr slow charge to prolong the battery life. The other thing I like about this charger is that I can use it anywhere in the world with the included 100-240VAC adapter.

http://thomasdistributing.com/...130dbb9c5e50d2bff55c21
 

zig3695

Golden Member
Feb 15, 2007
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if you can afford the low discharge stuff thats great.

about 4 years ago i won on the bay a bulk set of panasonic NiMH batts- 80 batts all together, for $55 shipped. ever since then i cannot stand to pay more then a dollar a AA and to be honest i havent even bought a NiMH since. Im still using them from that box! i cant even find a deal close to that one though anymore.... it was lucky.
 

potato28

Diamond Member
Jun 27, 2005
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Try to get something around 2000 mAh, Enloops have this capacity if I remember right. Im using an Energizer set, which runs at 2500 mAh. Charger is really slow, but the batteries last a really long time in Wiimotes and 360 controllers.
 

pm

Elite Member Mobile Devices
Jan 25, 2000
7,419
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I'd just get a bunch of 2500mAh or higher AA NiMH cells from either Batteryspace.com or All-battery.com along with an auto-shut-off charger. I have purchased a fair bit from both companies and they are both reliable in my experience. Ideally, ones with low-discharge are nice, but they are expensive, and if you are eating through batteries now, then presumably they won't have a lot of time to self-discharge on the charger.

http://www.batteryspace.com/in...=VIEWCATS&Category=201

or

http://www.*****/index.a...n=VIEWCATS&Category=25
(I got an 11% off coupon in email from all-battery about a week ago - they are fine with people sharing it... in fact they actively encourage it. Due to Anandtech forum restrictions, I can't post it here. Email or pm me if you want the code)

Note, however, that both of the linked pages are for cheap timed-based chargers. They work, but you won't get a full 2600mAh out of them... you get what you pay for. But the nice thing about batteryspace and all-battery is that you aren't paying much. The batteries that they sell will solve your problem, and their deals are cheap... but you need to spend more money if you want the cells to last longer between charges.

For more advanced chargers and better batteries, try Thomas Distributing, as mentioned above by Doclife.
 

pm

Elite Member Mobile Devices
Jan 25, 2000
7,419
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The charger listed is a initial high-current then low trickle current timed charger. They are fine enough for what they are, but if you put a completely drained battery in and then wait until the light turns green and take it off right away, it will almost definitely be undercharged by 20-40% (depending on how close to fully drained they are, and how the charger has the timer/current set up). On the other hand, if you leave them in indefinitely, they will definitely be overcharged (which will gradually wear them out faster). If you are willing to deal with the limitations of the charger - which is that it's slow, and that it will tend to undercharge initially and then overcharge over the long term, then I'm sure it will be fine. It's not junk.

But if you want a charger that will take them all the way up to 2600mAh and then shut off without overcharging, you'll want to get one of the so-called "smart chargers" which watch for the ~20mV peak voltage drop of the NiMh charging cycle to know when the cell is fully charged. Batteryspace calls them "negative delta V cut-off detection IC chargers" or IC chargers or "smart" chargers.

For what you are doing, I think you'll be happy enough with a timed charger - particularly if you leave the cells in overnight. But I wouldn't just leave the batteries sitting in the charger under the trickle current mode for weeks on end - the constantly overcharging trickle charge mode will gradually wear them out, and they'll be wimping out on you in 12-18 months. On the other hand, if you are worried, then I'd suggest paying the roughly $10 more for a "smart" charger.

Smart charger and 20 cells for $5 more:
http://www.batteryspace.com/in...n=VIEWPROD&ProdID=1098

Oh, one last thing - google something like batteryspace coupon code - you can save a couple of dollars.
 
Feb 19, 2001
20,155
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Originally posted by: Doclife
I recommend that you get the low discharging NiMH rechargeable batteries. Basically, with the low discharging type, once you charged up the battery, the battery will retain about 85% of the charge after 1 year of storage (very convenience and ideal for use in TV/DVD remote controller). Regular NiMH rechargeable batteries will self discharge to 0% after a month or so, whether you use it or not.

The low discharging type I use is Eneloop, made by Sanyo.

http://thomasdistributing.com/...130dbb9c5e50d2bff55c21

The charger I use is the Maha 401FS with the 100-240VAC adapter. I like this charger because I have the option to charge the battery from 0 to full in 100min for emergency or the 5hr slow charge to prolong the battery life. The other thing I like about this charger is that I can use it anywhere in the world with the included 100-240VAC adapter.

http://thomasdistributing.com/...130dbb9c5e50d2bff55c21

Are you sure they discharge that quickly? I only had to recharge my Ti-89 batteries last night. I recall using them through finals last semester. I recharge maybe once a semester usually.

Think of it this way.... rechargeable batteries are an investment. Once you recharge like 3 times you already got your money's worth.
 

pm

Elite Member Mobile Devices
Jan 25, 2000
7,419
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Originally posted by: DLeRium
Originally posted by: Doclife
Regular NiMH rechargeable batteries will self discharge to 0% after a month or so, whether you use it or not.

Are you sure they discharge that quickly? I only had to recharge my Ti-89 batteries last night. I recall using them through finals last semester. I recharge maybe once a semester usually.

Typical NiMH cells lose about 20-30% of their charge every 30 days - although this strongly dependent on temperature (lower temperatures slow the process considerably).

For reference:
http://www.batteryuniversity.com/partone-3.htm
http://www.duracell.com/oem/re...ble/Nickel/selfdis.asp

The wikipedia entry for NiMH cites the battery university link, so I skipped it. The graph on the Duracell battery is pretty typical of what I've seen... maybe a bit better than average but not by much. I usually have seen a sharper drop in the first 24 hours than the Duracell graph shows.
 

zig3695

Golden Member
Feb 15, 2007
1,240
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they way i see it- if your device takes longer then 2 months to drain the batteries then just buy cheap alkalines. most people buy rechargeables for their high drain devices, stuff that the batteries die often in, the natural discharge is hardly a matter at all....
 

Doclife

Senior member
Oct 7, 2007
414
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0
I only speak from personal experience. I have 4 Energizer 2500mAh and 8 Duracel 2500mAh batteries. I charged them up and left them in my drawer. About a month later, I inserted them (4 batteries) to my digital camera and my camera would not power up. This happened many times. Some of those batteries even loss their charge after a week or so.

Now, I only charge those batteries 1 day before I actually need to use them.
 

pm

Elite Member Mobile Devices
Jan 25, 2000
7,419
22
81
What kind of charger did you use, Doclife? I would guess it's something like a timed charger - where essentially the charger charges at a fairly conservative rate for a fixed period of time and then gives up. Since it's on a timer, it really has no idea if the cells are fully charged or not, and since it doesn't know the size of the cell that you inserted, they are usually configured to assume that you put in a smaller cell (so as to avoid overcharging). So then it is consistently undercharging the cells... so rather than charging from 0% to 100%, you get something like 0% to 70% (if it's sized correctly) or, if it's a bad design or one that's intended to charge both AA's and AAA's it can be doing something more like 0% to 40%.

NiMH self-discharge at about 30% per month - which is a really high number compared to any other mainstream chemistry - but they do not lose 100% of their charge in less than a week. Either your cells are faulty, or your charger is not sized appropriately for the cells. I would guess the latter.

If you post up the model number and manufacturer of the charger and the cells, I can see if I can google them.
 

Doclife

Senior member
Oct 7, 2007
414
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Thanks PM.

My charger is the Maha C401FS and I'm pretty sure that it is a smart charger. Incidently, I forgot to mention that I also have 4 Powerex 2700mAh batteries and I have charged them up, left them in the drawer for over a month and they still have charge left when I used them. I think that some of my Energizer and Duracel batteries are faulty. My cousin also complained about his Energizer batteries being discharged in a matter of days.
 

pm

Elite Member Mobile Devices
Jan 25, 2000
7,419
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Yeah, that's a nice charger. Pulsed charging, 1A peak rate, and deltaV detection. Very nice.

I think you are right. It must be the cells.