[NTLK] AA NiMH Rechargeables

[Joel M. Sciamma]

Tony wrote:

> I was intrigued by Joel's comment about speed of charging; Sanyo's  
> own charger seems to be able to charge two AA batteries in about 4  
> hours or so. My only criticism of the pack I have is that the  
> charger only charges two batteries at once - but if they only take 4  
> hours, it's not too much of a hassle.

This comes from my reading of Sanyo's tech documentation (which is  
commendably detailed) and the 4 hour charge time is at the top end of  
what is advisable for the best life of the cells. One hour chargers  
would reduce cell life considerably and lower charge rates increase  
it. Sanyo will have chosen a four hour charge to stop people being put  
off compared to the standard competition where even 15 minute chargers  
are sold.

I use the BL700 charger which allows the charge rate to be selected  
when you install the cells and gives a readout of the rate etc. on its  
LCD. The default charge rate is 200mA and I'm happy to use that for  
the Eneloops to maximise their cell life. If you need a faster charge  
then the 500mA setting is fine.

I use the same charger to fast charge my conventional NiMH cells to  
the rating suggested by the manufacturer.

As for availability, I bought several times from Amazon.co.uk reseller  
'digitalmediastore' from whom I have had good service and the prices  
seem competitive, especially for the 8x AA pack they supply.

I had a look at the Uniross equivalent cell but I am not convinced  
that it performs as well as the Eneloop and there is very little  
information about them. I have used conventional Uniross NiMH cells  
and have been happy with the 2300MAh cells but the 2500MAh versions  
have a very high self-discharge so are better for high current  
applications shortly after charging (when they have cooled down) like  
flash guns, motorised toys etc. I am gradually swapping these for  
Eneloops which perform better still and are always ready to use.

Good news if C an D cell Eneloops are on the way. I don't use many but  
it would save having to buy alkalines in the future though a new  
charger would be required.

Joel.