Battery Charging Problem

[grig]

Put Brandnew Outof Package Hydrimax Nickel Metal Hydride 1200 Tx 9.6 Batteryon My Hobbico Elite Charger At 1.20amps..........shouldhave Gone For 12 Hours As This Was First Charge On Battery..........but Charger Timed Out After 25 Minutes So Put It On Trickle Charge At 30ma And After 15 Minutes Or So I Noticed My Tx Case On Backside Where Battery Is Located Was Really Hot..........the Battery Was Almost Too Hot To Touch So Put It In Freezer.....................after 15 Minutes Took It Out And Put Back In Tx And Screen Showed 10.8v..................no Way Battery In Just 25 Minutes Got Fully Charged So What Gives???

[SilverFoxCPF]

Hello Grig,

Let's see now... a 9.6 volt pack should have 8 cells in it. At full charge you should end up with around 8*1.44 = 11.5 volts.

It sounds like your cells were roughly half charged in the beginning.

The reason you pack is getting hot is that the cells are out of balance. You need to discharge the pack at roughly a 1 amp discharge rate, down to a total pack voltage of 8 volts. Then you can charge the pack at 0.12 amps for 16 hours. This will form the cells and balance the pack.

Your other choice is to start from where you are at and charge at 0.12 amps for about 4 - 5 hours. This isn't as good, but may get the job done.

Tom