Rechargeable Batteries

[ng12345]

I've realized that this forum is pretty knowledgeable when it comes to anything related to electronics, so I"ve decided to throw this question out there, in the hopes that I will get some good replies.

Just bought the sandisk micro mp3 companion despite the mixed reviews, with a 2gb sandisk micro.

i have to say that though it may feel cheaply made ... it sounds good enough for my ears and it gets the job done.

However... the one thing I didn't want in a flash mp3 player was a non rechargeable battery... unfortunately this one requires AAA batteries.

I have never bought rechargeable Ni-mh or alkaline batteries before ... and thus my dilemma ... what do I get?

From my basic knowledge of anything ... i think higher mAh yields longer lasting batteries

The largest mAh battery i found is made by a company called mittoni based in australia and it has 1000mAh. Some forum indicated that AAA batteries as high as 1350mAh exist, but again it is made by some no name company.

The highest "name brand" battery clocks in at 800mAh.

Does anyone have any experience with Ni-mh batteries... and could they recommend a good one. The Sandisk micro indicates a 9 hour lifespan on a regular AAA, I'm hoping to get 18-20 hours with a rechargeable in there, if not more

I tried looking for battery review sites. .. but i couldn't really find one that specifically tested the brands I"m interested in

Thanks for replies

 

[ShaneDOTM]

while I don't have much in the way of experience with brands of batteries, I can confirm that the mAh is basically the indicator for length of charge. Generally, the brand doesn't matter that much. kinda like the Pepsi/Coke thing, it all tastes like soda to me. Take a look at the back of your unit and find the power usage. you should be able to take that and figure out how much time youll get out of the batteries. Also, try and stick to the Ni-Mh batteries as they are more resistant to "charge memory" or the reduction of charge capabilities.

good luck,

 

[oznerol]

Electronics 101:

mAh = milliamp hours = the time (in hours) a battery will last at a given amperage (current)

So say the player uses (on average, while powered on), 80 milliamps of current - an 800 mAh battery will last (roughly) 10 hours. If it uses 800 milliamps, 1 hour. Etc.

First step is to find out how much power this puppy requires to run, I doubt it's much. You probably won't get a rating in milliamps, but rather in watts. If the thing takes 1 AAA battery, then it takes 1.5 Volts. So if you know the watts it takes to run, just divide that number by 1.5 (P = IV, so I = P/V), and you have yourself the amperage required. With that number, you can calculate the hours it will run on whatever rechargeable you can find.

In my opinion, buying expensive batteries is unneccesary. Find a deal on a pack of energizer rechargeables and a charger, and just swap them when needed. I imagine one battery will get you 10-12 hours of life, depending on how much of a power consumer the device is.

 

[0roo0roo]

assuming the mah is correct yup. but its hard to argue with sale cheap batteries. nihm is so cheap per charge use its no point getting too anal about it.

 

[Budmantom]

I have had great luck with Powerex batteries, my Powerex AA outlast many other 2300-2500 batteries. It's not as simple as a higher maha rating equals a better battery when your talking about different brands.


Tom

 

[Fullmetal Chocobo]

I've bought NiMH rechargeable batteries that just came in a green color, and they were excellent. I got them off of Ebay, and didn't have any problems...
Tas.

 

[Varun]

Be sure they are 1.5V batteries, some rechargeables are 1.2V.

 

[oznerol]

Originally posted by: Varun
Be sure they are 1.5V batteries, some rechargeables are 1.2V.

As far as I know, all rechargeables are 1.2V.

However, they maintain a constant voltage of 1.2V while steadily decrease in current. Whereas regular batteries fall well below 1.5V, down to even the sub-1V level as they die out.

 

[Varun]

You are correct I thought I saw some at 1.5V but that isn't the case.

 

[ng12345]

thanks for the quick replies

looked it up... 1.2v nimh are compatible with gadgets that use 1.5v alkaline batteries

my main question i guess...is what would you consider the best charger/battery combo

i noticed some 900mah green nimh AAA batteries on ebay with charger

but then a forum indicated:
"The Powatech battery charger appears to be an inferior Mexican knock-off of a MAHA Powertech unit. There's no website for Powatech, and a Google search yields identical blurbs from a bevy of Mexican websites. Along with the eBay entry, all these sites seem to indicate a one-man campaign to push this product."

Tas... i'm guessing these are the batteries you got ... how do they compare to alkaline batteries (i.e. how much longer charge do they hold) ... did you get the charger from there also? what was your experience all round?

i've heard complaints of some chargers charging aaa batteries too much to the point where they overheat ... any experience with this... and recommendations?

thanks again

 

[poisonthewell]

I was doing the same type of research you were recently - nearly all of the camera enthusiast forums I visited (I purchased a Canon Powershot a95) said spending less than $60 on a charger and $20 on a set of 4 batteries was a waste.

What a load of crap.

After visiting Wal-Mart I picked up an 8 pack of Energizer rechageables (2200 or 2400 nimh i think) for about $10. The charger was separate and came with another 4 2200s/2400s and was $20 or so. I was a bit hesitant but decided to go for it just to try them out and have not regretted doing so at all.

Just make sure you have a backup set of batteries charged and ready for when the ones in your device are out of juice.

I've seen coupons for these exact items in the hot deals forum so you should be able to score a good deal on these.

Sorry for the long-winded explanation - I figured it'd help more than a simple "buy energizer" post.

 

[ng12345]

thanks for the recommendation

did you happen to find a review comparing AAA batteries?

anyone have any experience wtih the lenmar brand of rechargeables? they are sold at staples

 

[eplebnista]

Originally posted by: ng12345
thanks for the recommendation

did you happen to find a review comparing AAA batteries?

anyone have any experience wtih the lenmar brand of rechargeables? they are sold at staples

curiosity bump

 

[JimPhelpsMI]

Hi, Alkaline starts at about 1.6 Volts per cell and gradually tapers down. The device may sense the battery voltage and shut off at about 1.2 Volts per cell. Some rechargables start at about 1.35 and drop, very rapidly to 1.2 volts and hang there for the rest of their useful life. Devices that sense the voltage and shut down will get very little time off these rechargeables. Lithium rechargeables do start at 1.5 Volts, but I have no specs on them so can't really say how they will go. Hope this helps a little, Jim

 

[ND40oz]

Originally posted by: poisonthewell
I was doing the same type of research you were recently - nearly all of the camera enthusiast forums I visited (I purchased a Canon Powershot a95) said spending less than $60 on a charger and $20 on a set of 4 batteries was a waste.

What a load of crap.

After visiting Wal-Mart I picked up an 8 pack of Energizer rechageables (2200 or 2400 nimh i think) for about $10. The charger was separate and came with another 4 2200s/2400s and was $20 or so. I was a bit hesitant but decided to go for it just to try them out and have not regretted doing so at all.

Just make sure you have a backup set of batteries charged and ready for when the ones in your device are out of juice.

I've seen coupons for these exact items in the hot deals forum so you should be able to score a good deal on these.

Sorry for the long-winded explanation - I figured it'd help more than a simple "buy energizer" post.

I have these, pretty quick to charge, but they didn't seem to last that long. I got about 2 weeks of usage from my mouse with these. It's the MS Bluetooth, so it does suck down batteries. This compares to 2 months of use with regular duracells in it.

 

[Fresh Daemon]

Just a note about no-name batteries:

I got a few dirt-cheap Wal-Mart rechargeables. Three of them burst and leaked inside the charger. Out of six, that's a very poor record. This was only after a few-dozen charges.

I had ten Duracell rechargeables that I bought months before. They're still going strong.

You get what you pay for. You might get similar capacity from no-name batteries, but the longevity will be considerably less.

 

[Pabster]

Rayovac IC-3!