[ozshadow]

I am using this trickle charger circuit.

http://www6.head-fi.org/forums/showthread.php?t=185796

The batts get 24.0v They are two 270 mAh 8.6v batteries. I used a 47 ohm resistor.

Whats the charging rate ?

 

[error401]

As tangent lays out in the thread you linked, the charge current for this circuit is given by R = 1.25/I, or I = 1.25/R. With R=47, charge current is ~27mA. Assuming the batteries are in series, the charge rate is given as a coefficient of C, the capacity of the battery and is equal to the charge current. 27mA = nC. C=270, therefore n = 27/270, or 0.1. Your charge rate is the 'recommended' trickle charge rate of 0.1C.

Batteries should not generally be charged in parallel.

Edit: typo.