While looking on another forum (home theater remote controls), I noticed a post about a replacement battery pack. When I looked into it, at first it looked like a simple 4 cell pack. I then found a diagram for the pack and it has a thermistor and resettable thermal fuse.

I was wondering why our packs don't need those devices.

The Sanyo camera battery packs that I have used occasionally do have something like you describe. There was no fuse and the component was not marked however it measures zero ohm at room temperature. The last pack purchased was several months ago and the cost was $19.95 for a five-cell 1600mah pack at ‘Best Buy’.

The camera fast charger takes less than 30 minutes to charge. If the pack is immediately disconnected and reconnected it will charge about five minutes and shut down.

Hope the information is helpful.

Bill

The Multiplex EVO packs use an automatically resetting thermal fuse, but I doubt if it will offer much protection for the radio circuitry. It appears to be rated at 200watts, and by the time it opens, I'd imagine that a couple of traces in the radio are going to fry.

Highflight

This particular pack goes into the remote which then sits in a charging "cradle". Except for being more of a "consumer" product, leaving it on the cradle would be like leaving a plane on charge?

I'm assuming there is some feedback from that third lead which we have no need for due to advanced charging circuits in our chargers. (?)

While I don’t know which charging cradle is being discussed the camera charging cradle stops charging and changes the state of the ready lights. Somehow it never occurred that the pack might have gone to trickled charge when finished. Don't know.

The thermistor is used during the carging process.It detects a high temperature in the battery pack and interupts (stops) the carging process until the temperature returns to normal.The charger for my cordless drill uses the same thing.
The fuse is in series with the battery,and would open the circuit in the event of an "overload".I don't want a fuse in my receiver power supply.Even in an overload condition,I would rather risk destroying my receiver and servos.And have at least some chance of getting the plane on the ground,without property damage,or personal injury(to myself ,or others.
This is just my opinion! You are free to make your own choice,and I to mine!I personaly choose to remain in control and attempt to fly the plane to the site of any eventual "Crash"!

Did not know about the fuse and have been flying blind. Thanks. Now an informed decision must be made. Hate it when that happens.

Bill