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View Full Version : Rechareable Batteries



Rob99
31-12-2004, 10:55 AM
I need AAA, AA, C and D for kids toys etc

I have tried new battries and charger from dse, they are Nicad.

They seem to be absoulte ****, the AAA's I used in a little walkie talkie last about an hour or less. An MP3 player can drain one of these in 20min's.

They have been charged for the correct time bla bla bla, so I am thinking I will return them as they do not do what they are ment to do.(hold charge for a reasonable amount of time)

I am still keen on getting recharegable batteries, so which do I buy and where from in Chch

Cheers Rob

Tony
31-12-2004, 11:15 AM
Although they are more expensive up front, I think NiMH batteries are the way to go. They don't have the memory effect problem (I think) and are more efficient. Also NiCad batteries are a toxic hazard when you finally come to dispose of them.

You do need to make sure your charger will charge NiMH batteries.

HTH

Rob99
31-12-2004, 11:22 AM
Thanks Tony,

I know DSE have NiMH in stock in the Digitor brand, are these good?

Should I be looking elsewhere.

Cost is not a problem, I just want the best.

godfather
31-12-2004, 11:40 AM
The thing you should be looking at is the capacity (mA/h) rating. That is what determines the "life" in a device, more than the composition (NiCd or NiMh).

They all have a "self discharge" of a couple of % per day.

Try Jaycar for a good range, but try and buy the highest mA/h rating you can, the DSE ones are usually fine though.

Remember that if the device is designed for alkaline 1.5v cells, then it may see 1.2v rechargeables as partially flat even if they are fully charged. Thats a matter of the device characteristics and not a fault of the battery.

Tony
31-12-2004, 11:42 AM
I've used Digitor and they seem to be OK. There are other people in this forum who would be much more knowledgeable than I am. One thing to look for is the mAh rating - more is better. This I think is where Digitor maybe fall down slightly - the batteries I have in my mouse are AA Digitor 1700mAh, whereas in my digital camera I have AA Energizer 2300mAh.

I repeat, make sure your charger can cope with NiMH batteries, otherwise you can literally explode them.

robsonde
31-12-2004, 12:10 PM
when buying batteries check the mAh rating, this is the amount of charge the battery will hold.

a AAA might be cheep but if its only 1200mAh then its not going to last as long as a 2300mAh.

Eric
31-12-2004, 12:11 PM
Here is a web site that has good information on secondary cells
http://www.batteryuniversity.com/

By the way shouldn't this topic be on the OT part of PressF1 , just a observation I am not tring to be Mr. policeman.

zqwerty
31-12-2004, 01:52 PM
NiMH batts mostly have about twice the mAh rating of NiCds for the same physical size.

Graham L
31-12-2004, 02:07 PM
The AAA's could have been 250 mAh or 300 mAh. They would be holding "a reasonable charge for a reasonable time". It's most likely your walkie-talkies and player which are using "unreasonable" currents.

AA's at 600 mAh would also appear to be poor performers. 2100 mAh ones would be much better.

As an example, AA alkaline (non-rechargeable) cells have a capacity of 2850 mAh. This, and the higher starting voltage means they will behave better than rechargeables. But it's still very expensive electricity (per kWh).

NiMH's are "better batteries" but for high drain applications NiCd's can perform better.

Don't worry about charging NiMH on a NiCD charger. They won't explode (unless you manage to do something really strange ;) ). The only problem is that a NiCD charger will "trickle" charge at a higher rate than NiMH like after the cells are fully charged. This can shorten the life of the NiMH cells. The solution is to turn the charger off after the recommended time. An intelligent charger is the answer. Jaycar have a fairly good range.

I have seen really fast charging Varta NiMH AAs in a Mitre 10 shop. They charge in 15 minutes (on their proprietary charger) . A 4 cell charger (with 4 2000 mAh AAs costs about $100.

Rob99
31-12-2004, 02:45 PM
Thanks for the jaycar tip gf.

Just spent $174 there and came out with 4XC MiMH 4500mAh and 2XD MiCD 5000mAh and a charger.(far out that was bloody expensive)

The do have 9000mAh D size batteries as well but at over $30ea I grabed the 5000mAh instead for aroun $15 each.

Thanks everyone.

Jeff
31-12-2004, 02:47 PM
Go to Battery Masta, Cnr Carlyle and Gasson Streets here in Christchurch (Near the old Railway Station).
Tell them what you want and he will sell the battries to do the job. I have dealt with them before and have found them very helpful. If I remember right they will have chargers as well.

www.batterymasta.co.nz

Rob99
31-12-2004, 02:51 PM
Go to Battery Masta
Darn it, never tried there. :@@:

drb1
31-12-2004, 03:37 PM
Darn it, never tried there. :@@:

Robb,

Dont worry, quality never goes (Completly) out of style.

D.

Tony
31-12-2004, 05:30 PM
Don't worry about charging NiMH on a NiCD charger. They won't explode (unless you manage to do something really strange

I made the comment because when I bought some NiMH batteries and a DSE charger the guy in the shop was most emphatic that you should have the charger on the right setting, and quoted from personal experience of someone who had had a battery explode. Was he maybe talking about charging Nicad on a NiMH setting?

:confused:

Cicero
31-12-2004, 05:49 PM
By the way shouldn't this topic be on the OT part of PressF1 , just a observation I am not tring to be Mr. policeman.[/QUOTE]


By jove I think you are right,spoiled my day as that. :rolleyes:

Rob99
31-12-2004, 10:42 PM
By the way shouldn't this topic be on the OT part of PressF1 , just a observation I am not tring to be Mr. policeman.
By OT part of PressF1 do you mean the kiddie section

~sy~
31-12-2004, 10:48 PM
By OT part of PressF1 do you mean the kiddie section
No it's not the kiddie section. It's just the offtopic section for anything non-computer related ;)

Cicero
31-12-2004, 11:17 PM
No it's not the kiddie section. It's just the offtopic section for anything non-computer related ;)

Thanks for that SY,would have been another sleepless night if you hadn't cleared that up.
:rolleyes: