I have noticed that with rechargeable batteries the active life for the Model 100 is shorter. This is because most rechargeable batteries follow a curved path for power drain. They only maintain the 1.5 volts for s short time then tend to drop lower for the remainder of their power drain. When the power drops low enough the Model 100 activates the low power light and then goes down.
There are some exceptions to this discharge path. The EBL rechargeable batteries hold the 1.5 voltage across their drain, however then they drop off sharply causing a shutdown when they are at the end of the discharge cycle. Not really an issue for me as I use the Rex and Jeff's backpack so I can save often on projects. Just some of the tradeoffs I have noticed when using rechargeable batteries. In regards to the backup battery, the advantages do outweigh the disadvantages. If you are only running on installed batteries then the backup battery will recharge from them continuously, reducing the battery life. However if you use a wall outlet or usb power cable then it will extend the life of the batteries by charging the backup off of the power cable instead of the installed batteries. I have considered installing NiCad's, however this requires a little soldering, so I am not sure if it is worth it. For now I just use a combination of the EBL batteries and a USB power cable I found on Ebay that works really well. Just my observations on this. Please correct me if I am wrong in any of this. Have a great week! -Allan Zieser
