Can you recomend me batteries?

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I have bought some cheap from China Ni-MH AA size batteries, supposed to be 2600 mah.
Two of them can´t be charged, may be damaged.
The others charges ok but seems not have much duration on my walkie talkies. I know that walkies often have much consumption but seems not all have the same duration.
Is there any way to test how much are the real mah they have?

more questions: the Ni-MH batteries have less capacity on the first cycles?
I got a smart charger for Ni-MH battery packs, from 9.6 to 18V. It charge at constant current of 0.9 amp or 1.8 selectable.
Could be use this charger for a 12 lead battery?
And for Li-Ion batteries? Could be the constant current used or is any risk?

I would like to build a 12V pack at 7ah aprox. what do you recomend me? Cheap size AA batteries? Size AA batteries of a known firm? or another size batteries? What is the best price/ratio you recomend to can get those 7000 mah aprox at 12V?
 
lagoausente said:
I have bought some cheap from China Ni-MH AA size batteries, supposed to be 2600 mah.
Two of them can´t be charged, may be damaged.
The others charges ok but seems not have much duration on my walkie talkies. I know that walkies often have much consumption but seems not all have the same duration.
Is there any way to test how much are the real mah they have?

more questions: the Ni-MH batteries have less capacity on the first cycles?
I got a smart charger for Ni-MH battery packs, from 9.6 to 18V. It charge at constant current of 0.9 amp or 1.8 selectable.
Could be use this charger for a 12 lead battery?
And for Li-Ion batteries? Could be the constant current used or is any risk?

I would like to build a 12V pack at 7ah aprox. what do you recomend me? Cheap size AA batteries? Size AA batteries of a known firm? or another size batteries? What is the best price/ratio you recomend to can get those 7000 mah aprox at 12V?

Lag:

I think the AA batteries you bought, make in China is Jerry made!
whether it stated, only count on 50% of it's capacity.
When new batteries are to be used, the first 5 cycle is not stabled, if after 5 running cycle has accomplished, then you can calculate it's capacity ( current X hour ), all batteries are stated in current per hour.

If you want 12V 7A DC source, the best way is use Lead acid gel type, the same spec. that you wanted. Shop around and find your target.

Good luck and happy holidays
 
Glowbug said:
Any size limitations?

7Ah AGM/gel cells are about the size of a standard brick, are nonspillable, and pretty cheap to find on Ebay.

The AGM/cell are lead acid?

The lead batteries a too much heavy. No problem for the size itself, but a 7 ah lead has a 2kg of weight.
I have one, could I charge it with the Ni-MH smart charger or must be any damaged for the lead ones charging at constant current?
 
lagoausente said:
This are the ones I bought:
http://stores.ebay.es/Good-Shop-To-...colZ4QQdirZ1QQfsubZ4921685QQftidZ2QQpZ2QQtZkm



What do you think about this ones?
http://cgi.ebay.es/8-NiMH-4500-mAh-...hZ008QQcategoryZ50623QQtcZphotoQQcmdZViewItem

Do you think it´s worth to spend on a known firm like Energizer or something like that?

you can charge almost any battery with any charger, HOWEVER< the battery can EXPLODE if the mah/ah rate is not correct OR the battery will not be charged all of the way or its life will be shortened if it DOE NOT EXPLODE> SO.......

www.midtronics.com/battery/pdf/BatteryChargingBasics.pdf

www.batteryuniversity.com/partone.htm

CHARGING A BATTERY CAN BE DANGEROUS< EXPLOSIONS< FIRE< BURNS< INJURY< DEATH>

please read more, ask more questions...
 
The links was very useful. Thanks a lot.
Although I have to go in defense of the China cheap batteries. I tested the capacity and it result was perfect. They gived exactly the 2600 mah. Running little more than 1 amp, they worked 2 hours and a half.
For now the issue is solved for me. At the price of this NIMH are nearly the same as a lead battery.
I have learned that the lead batteries don´t like much depth discharges, so must take a "big " one to have it with good health. And must be applying often charging to avoid it get discharged.
So prefer the NiMH for the price the ones I have got.
The bug is that the walkie talkie I was using, consume "5 amp" at "medium" wattage setting, and 7 amp at high. So that was what made the batteries discharge so quickly.
So I´ll set the walkie to Low, where it consumes 1 amp, what is 5 times less than on "medium" setting.
Finally, nothin bad on this China batteries for now.
 
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