Rules of thumb for cooling

[John Emms 1]

Erfolg makes a really good point, that if the outer two cells in a 3S pack are warm, then the inner cell is going to be warmer - and it would appear, at greater risk of short life (though I have no evidence to support this).

On reliablity of different brands: A handful of brands can be from the same manufacturer, but I have not been able to recognise which brands share a common manufacturer - and there are also more than a couple of manufacturers....

I have been using the Pelikan Ray and Foxy brands, partly for obvious reasons, and partly because Daniel Pelikan can choose from any manufacturer (and Daniel would never knowingly sell me anything that was less than good).

I also have an internal resistance meter, and although the Ray are more than capable of supplying the current I need, I will probably stick with the lower resistance (and heavier) Foxy in future. I suspect that the same cells as the Foxy are Overlander's premium range of batteries - the surface mount LEDs on the end of the pack help with identification.

[Nigel R]

John - intrigued to know - how does the internal resistance meter take its reading?

Also the elevated cell temperature, >50deg, I have read this leads to shorter cell life. My yardstick for temperature on most electricals is, if it hurts to hold it, it has got too hot.