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A_C
11-20-2006, 12:00 AM
Hey everyone.

Can i safely put AA NiMH batteries that were bought with an 8 hr charger into a 1 hr charger?
I have a Uniross 1 hr charger but i'd like new batteries with more mAhr in them. Can i just buy the batteries i'd like (not necessarily from the same manufacturer) and charge them with the charger i have?

Thanks...

David Metsky
11-20-2006, 06:30 AM
Yes, the batteries don't know anything about the chargers. They'll all be fine.

-dave-

Rhys
11-20-2006, 08:23 AM
With NiMh you really need a reconditioning charger or you'll get a couple of dozen charges from a set before you need to toss them.

David Metsky
11-20-2006, 09:48 AM
If the charger is designed for NiMH (I assume your 1 hour charger is) shouldn't it be OK?

AlexMonro
11-20-2006, 11:32 AM
You don't need a reconditioning charger - just ensure that they're fully discharged by leaving the camera on until it turns itself off every half dozen or so charge cycles. Some cameras, such as the Fuji S9500 / S9000 have a discharge mode in the menu.

Any charger designed for NiMH batteries should charge any NiMH batteries, but don't mix them with old NiCd chargers / batteries. Fast chargers (1 hr or less) are likely to cook the batteries slightly, so you'll probably get fewer charger cycles from the batteries if you use them all the time. Use a slow (8 hr) charger when you've got the time.

David Metsky
11-20-2006, 12:20 PM
Any charger designed for NiMH batteries should charge any NiMH batteries
I guess my question is "Are all chargers designed for NiMH batteries reconditioning chargers?"

-dave-

A_C
11-20-2006, 02:44 PM
Of charging at a slower charger to save battery life.

TNB
11-20-2006, 10:11 PM
Hey everyone.

Can i safely put AA NiMH batteries that were bought with an 8 hr charger into a 1 hr charger?
I have a Uniross 1 hr charger but i'd like new batteries with more mAhr in them. Can i just buy the batteries i'd like (not necessarily from the same manufacturer) and charge them with the charger i have?

Thanks...
Think of the larger mAH numbers like an automobile with a larger fuel tank--it should just get longer run time. The volts should be the same. Myself, I prefer to charge "sets" of the same brand batteries. Anyone here "match" batteries? That charge will only last as long as the weakest battery.

That one hour charger probably just charges at higher amps though batteries tend to have a longer life if slow charged. However, make sure that the 1 hour charger is actually for NiMH batteries and not NiCDs (doubtfully LiIons/LiPos/LeadGell). If the batteries get hot, quit charging them.

Something I posted on one of the other threads in response to another post:


Actually, you are NOT supposed to fully discharge LiPo (lithium-polymer cells not to be confused with lithium-ion) batteries which are NOT cheap. Some LiPo batteries also have an automatic cutoff (they are not supposed to be discharged beyond a certain point or charged beyond a certain point). In addition, LiPos should be charged at least once a year to prevent over discharge and should be stored at 30-50% capacity. Myself, I also use a thermal cutoff when charging LiPo cells--usually 11.1v 3-cell packs (LiPos have a higher cell voltage rating than the typical rechargeable battery).

NiCD (nickel-cadmium) cells are basically "memory" type batteries and should be discharged and/or recycled in order to obtain a full charge. If not, they will only charge from the developed memory, which means the typical charger may think the battery is fully charged yet it is not.

NiMH (nickel-metal hydride) cells on the other hand don't really have a memory, so those batteries don't necessarily need to be deep cycled. However, if the batteries haven't been charged for some time, it may be necessary to recycle them or "condition" them for them to achieve a full charge. These batteries should also be charged soon before use and not be "hot" when charging.

Myself, I own several chargers including a Triton computerized peak battery charger, discharger and cycler that charges: LiIons, LiPos, NiCd, NiMH, and Pb batteries. It also requires a separate power supply. However, I have yet to try and charge LiIons with it though the basic charge set up is the same as it is for LiPos.

The "length" of the charge also depends on the mAH rating--Thinking like an automobile fuel tank, the larger the number the more storage space. I don't know about anyone else, but the AAs I purchased at the camera store (for my Speedlight) where 2400mAH when I had already been using GP 2500mAHs for quite sometime. Of course, the hotter the charge, the less life of the battery.

A_C
11-22-2006, 02:59 AM
You'r right about the faster chargers charging with higher Amps, but i think it's also with higher Voltage as well. On the sticker on the back of my 1 Hr charger the output of the charger is said to be: DC 6V 1000 mA.
I also have a slow, 8 hr charger and its output is: DC 2.8V 130 mA.
So i guess both are important.

Of course, i want a larger mAH batteries to "enlarge my fuel tank", i just didn't want to buy another charger.

Thanks again.

Bob7766
11-22-2006, 04:17 AM
I guess my question is "Are all chargers designed for NiMH batteries reconditioning chargers?"

-dave-

Not all chargers for NiMH batteries are conditioning chargers. My charger has a conditioning cycle. I have options for milli amp charge rates and usually select a 200 ma/hr charge rate. For a 2400 ma AA battery a reconditioning charge takes 48 or more hours as it charges and discharges several times testing each battery to determine that it has reached full capacity.

By the way the charger will also provide the ma capacity of the battery after charging. This is useful for separating out severly undercapacity batteries, although with the dozen or so well recognized name brand NiMH batteries that I purchased none were less than 10% of rated capacity when new. However subjecting batteries to high charge rates will reduce the batteries life and the capacity will decrease.

By the way earlier this year I purchased 24 NiMH batteries for $24. A few were dead and could not be charged. Probably a third were more than 20% below there rated capacity. The company sent me 40 additional batteries at no charge so I ended up with 64 batteries. The 40 batteries had about the same problems as the origianal 24. But I can't complain.

TNB
11-22-2006, 09:09 AM
You'r right about the faster chargers charging with higher Amps, but i think it's also with higher Voltage as well.
When I wrote, "The volts should be the same" I was referring to the battery voltage. Of course, some charges can charge by "voltage" as well. Some rechargeables also show a .05 higher voltage rating, but that is probably just a marketing ploy. You may also notice that non-rechargeable batteries usually show a higher voltage rating; however, and more importantly at hand is that the discharge rate is different from rechargeable batteries. By the way, Radio Shack has an inexpensive battery charger that can charge between 1-8 AAs, AAAs, and a couple of 9V batteries--that's the slow charger I use when I am not in a hurry.

Bob7766
Why don't you tell us the brand name of your charger and the batteries? I'd like to know, so I don't purchase those batteries. Myself, I never take that long to cycle batteries, so either I am not cycling batteries as many times as you are or I am charging/discharging the batteries at a faster rate. Some of the high dollar chargers also print out spec sheets for each battery, i.e. Competition Electronics--which is very useful for matching batteries. Then there is the peak adjustment.

Below is a quick link to an article by one of the companies who puts out chargers used in the R/C market. I also have one of their brand chargers and power supplies.
http://www.teamnovak.com/tech_info/tech_info/chargers/index.html

Bob7766
11-22-2006, 05:37 PM
My charger is La Crosse Technology AlphaPower Battery Charger Model BC-900.

The batteries were Lenmar NoMem. However, I can't fault the price and the company providing me with replacement batteries. I use the batteries in a couple of Canon P&S, three portable radios, FRS radios, GPS devices, remotes so need a lot of batteries.

My brother is a radio controlled airplane enthusiast and he will only use Sanyo batteries as he claims there failure rate is low. My understanding is that any NiMH battery can suddenly fail?? Failure when you are flying a couple thousand dollar RC plane is not desirable.

Bob

talkingdog
11-27-2006, 06:32 AM
I use a peak charger for R/C Planes, I can charge at various rates. The Voltage and amprage both vary. My charger will only work properly with ni-cad as it is older. It will charge the nimh but not properly peak them. It is true the faster the charge the shorter the life. Also a slower charge gives more mah.
Not all 2500 mah batteries last the same amount of time. Consumer reports did a test and I think the Rayovac was one the better brands for holding their charge

TNB
11-28-2006, 05:05 PM
Bob,
Most people I know who are flying RC planes that expensive are using LiPos unless it is just for a receiver pack, then it is usually NiMHs. A well prepared RCer would also have several receiver packs as well or at least charge them between uses in the field. By the way, I also own around 60 RCs--helicopters, boats, cars, and a hydrofoam I have yet to put together. Types include gasoline/oil mix, nitro, and electric (brushed and brushless). By the way, one site provided the following about your charger, "All modes automatically default to a 200 mA charge."

Talkingdog,
In the smaller Kyosho Mini-Z Racers, I've tried Rayovacs and several other brands myself, including some Lenmar brands as mentioned in Bob's post--I had to cycle the heck out of those Lenmars when I first purchased them. However, those were AAAs.

Since I've had good luck with GP AAAs when racing the smaller Kyosho Mini-Zs on both a national and international level, I tend to use GP AAs in my SB800 though I have a few other brands (one brand purchased at the camera store and another set came with my Nomadio Sensor transmitter). Quite frankly, I've cooked the heck out the GP AAAs and charged them numerous times in one setting (that happens when running Zs 11-12 hours straight).

By the way, I noticed that your using a NiCD charger to charge NiMH batteries . . . A few NiMHs have blown around here (as well as LiPos) due to incorrect charging.

talkingdog
11-28-2006, 06:24 PM
No, actually I don't charge the nimh camera batteries with the peak charger. I do need to update my charger.(Year after I bought it they changed it to charge the nimh's, just my luck again) I only have a float plane now and don't have time to fly very often.Still have a couple of good nicad packs so I won't be getting the nimh's to soon. Maybe if I get a new scale plane. With the peak charger I only have about a 30 minute delay which is enough time to get ready for the next flight. To much trouble taking off the wing every flight to change batteries. I just have a charged spare pack in case mine goes bad suddenly. My nicad receiver batteries are apx 3 years old and still working fine. I don't cycle them unless they are setting a long time before I fly.

SpecialK
12-07-2006, 08:46 PM
You must use a charger designed for NiMHs with NiMH batteries. Ideally it should charge at a rate no higher than the capacity, therefore it should take at least an hour.

Powerex makes a highly-rated (by an online battery/charger tester guru) MH-C204W-Worldwide-Charger with 8 x 2700 mah for about $65, which is on the expensive side :-) 2 batteries in a hour, 4 in 2 hours, and the plug is not for "worldwide" use. It has a conditioning function as well.

TNB
12-08-2006, 01:09 AM
$65 is not expensive for a charger compared to something like Shulze, Competiton Electronics, Futaba, or even something like Novak, which also needs a separate power supply and doesn't come with batteries.

MatthewCollin
12-26-2006, 12:13 AM
Powerex makes a highly-rated (by an online battery/charger tester guru) MH-C204W-Worldwide-Charger with 8 x 2700 mah for about $65, which is on the expensive side :-) 2 batteries in a hour, 4 in 2 hours, and the plug is not for "worldwide" use. It has a conditioning function as well.

I just ordered the Powerex C204W with 4 of their 2700mah batteries last night. I've also read good things about it, and I'm hoping to get it soon because I just got my Canon A710IS yesterday for Christmas and it absolutely destroyed the alkaline batteries that were in the box in just a few hours. :o

It was about 41 dollars with free shipping for the charger and batteries from NewEgg.

outpost05
12-26-2006, 02:31 PM
I also have an A710IS. I use a Powerex C401-FS charger and 2700mah batteries. Those Powerex batteries are great. I had them in the camera for weeks, went on a 4 day trip. Took 300 shots, reviewed them several times in playback mode and never had to use my backup batteries.

hotlips69
12-30-2006, 10:23 PM
I've just read through this topic and I'm slightly confused being a novice in this sphere.

My question is basically: I've got a Maha MH-C204F charger and some 1600mah batteries.

Would this (or any other) charger be able to safely take higher mah batteries, i.e. 2500mah and would they last proportionately longer before running out that the equivalent brand 1600mah?

hotlips69
12-31-2006, 07:30 PM
Anyone?

I need a quick reply to my question please as I need to purchase the new batteries for my business asap.

talkingdog
01-01-2007, 06:20 PM
From your original posting the answer is no. But the charger you have can charge different mah sized batteries. The higher the mah the longer they will take to charge fully

hotlips69
01-01-2007, 06:24 PM
I'm actually pretty surprised at your answer Talkingdog as I assumed that it would take the higher mah batteries without being dangerous and you're telling me otherwise!!! :eek:

Obviously it would take longer to charge them up, but they would last longer when charged.

Are you 100% sure about your answer as I've been told otherwise elsewhere and am now confused!

talkingdog
01-02-2007, 01:45 PM
Can any NiMH AA battery go into any charger? was the original question and that answer is no. Sorry didn't notice you were not the originator of the thread. Yes your charger should be fine with different sized (amp hour rating) batteries that are NiMH. Sorry for the confussion

canon_A620
01-07-2007, 06:41 PM
The MH-C204x series charger don't have independent charging circuits, but parallel circuits. If the cells are at different capacities, undercharging of one cell can occur. For example, if one cells is 20% and the other 40%, the 20% cell will terminate charge when the 60% cell is full and charging terminated.

I love the BC-900, as it has independent circuits, an LCD display, and several charging modes that help to maintain NiMH cells. If the BC-900 doesn't suit your needs, look for a charger with independent charging circuits.