If you need an item to get the free shipping, it would make sense to go with a pack of Eneloop batteries to break in your new charger.

mdyoung said:I have a question about rechargeable batteries and chargers that I hope someone could answer. I have a Powerex MH-C240W charger and the Sanyo charger that came with the Eneloops. I have some older Energizer batteries that will not charger in the Powerex charger (the charge indicator lights start blinking), but the Sanyo charger charges them and the batteries seems to work fine otherwise. Is there a possible reason for this? Something wrong with the Powerex charger or with the batteries?
As cells age, their 'Internal Resistance' gradually increases. Some 'Smart' Chargers test the cell for this before they begin charging. (This test is also why those chargers will refuse to charge alkaline cells.)

If the 'Internal Resistance' is only marginally past the charger's limit, you can try warming the cell first (hold it inside a closed fist or charge it for a few minutes on another charger). If the Powerex then accepts it, that's your answer - the battery is worn out.

humphreydog said:Has anyone hooked up an adapter to use this on c and d size batteries?
Yes. But be advised that the La Crosse (I have a BC-900) is VERY sensitive to the total resistance in the circuit. I used 18" test leads (thin, maybe 24-26 gauge, EZ-Clip on one end, banana plug with alligator clip on the other) and although the BC-900 indicated it was charging, a DMM inserted into the circuit (adding even MORE leads with resistance) revealed that hardly any current was flowing.

IMO, to pull this off, you'd need short 16-18 gauge wires, a quality battery holder (those you can buy at RadioShack have too much resistance in the spring connectors) and a solid connection to the PLUS bus (it's much harder to connect to than the MINUS since it's recessed). Also, be warned that you lose the OVER TEMP protection since the C and/or D cell will not be touching the thermistor on the charger's case. You would have to personally monitor the cell's temp and not leave it unattended.

Another problem is that the BC-900 has a protective cutoff at 3000mAh (above all currently produced NiMH AA cells - the Sanyo 2700mAh is the highest I know of) so you would have to re-start it multiple times to fully charge a depleted 'REAL' C and/or D cell.

Overall, you're probably better off getting a charger designed to handle C and/or D cells. And one that can handle 6000mAh and higher cells properly is going to cost you some SERIOUS change.