AA NiMH safe discharge rate?

[ltiu]

Is there such a thing as an unsafe discharge rate for AA NiMH?

Specifically the Duracell 2650.

Is there a max limit above which it may explode/leak?

What is the record for the max discharge rate for AA NiMH? 3amps or 4amps or more?

 

[shadowjk]

Silverfox has tested various cells: http://www.candlepowerforums.com/vb/showthread.php?t=79302

Eneloop manages 10Amps, for example.

 

[SilverFox]

Hello Ltiu,

Most NiMh cells are rated for a maximum discharge rate that discharges a full cell in 30 minutes.

I use heat and voltage retention under load as indicators when you are over the maximum discharge limit. In testing, I push things to the limits to show the differences in the various cells. When a cell heats up during discharge, I know that I am approaching its limit.

Tom

 

[mdocod]

hobby style cells that are designed for high current applications can often handle 10-20 amps without breaking a sweat. Absolute limit, I'd imagine that a cell designed for RC cars and such could probably deliver pulse rates as high as 40 amps, but voltage would probably dip below 1V per cell...

 

[Anders]

Hello ltiu.


This is from TECHBULL.pdf (from Duracell) Ni-MH Rechargeable Batteries.

"• High rate discharge — Efficient discharge at rates
as high as 2C."
http://www.duracell.com/OEM/Pdf/others/TECHBULL.pdf

This is the only limit I see in this document. Probably can they handle more.

Exactly what Guru Tom said, 2C.:twothumbs

Anders