How much do good batteries matter?

A old or week cell will have a voltage sag sooner than a new or Hi-Capacity cell, as the voltage sags the boost driver will increase the current from the cell to make up for the lack of voltage.

This increase in current now flowing in the driver is what heat's up the driver faster and causes them to blink when the over temp protection circuit kicks in.

Old or weak cells are fine for low power applications so don't throw them in the recycle just yet

Here's a good thing to do get a load and a amp meter and find out how many mAh's are left in them by charging and discharging them and then write it on the cell so they don't get mixed up with you Hi-Capacity cells.
There are ready made meters out there that will do this for you.

Jackagain said:

This guy did a review on the Soshine:

Soshine SC-S2, Li-Ion Charger..

Ebay has it with 2 Ultrafire 3,000's for $38.80 or $40.00 bid with 2 Soshine protected 2,800 mAh batteries.

Click to expand...

That is 2 years old review - Soshine upgraded 2 versions since then.

Very good, safe, and fast charger.