Hello everyone,
I built a battery circuit based on Maxim712 chip. I have attached my circuit and the board layout. I have set the charge time to 90 mins at 2 amps charging current. I have used BD 132 for fast charging.
I have serious problem with heat. Both my transistor and batteries become extremely hot. The transistor is connected to a decent heat sink. Data sheet show that max Ic for BD132 is 2 A. I measure 1.8 A flowing into the battery and around 1.4 V across each cell. I am bit worried that I might damage my batteries. I am using sony 2100mAh (four of them) batteries to charge.
Is my transistor getting hot bcoz I am close to its rating. Is is some other way to solve the heating issue. The data sheet shows the use of thermistors although its not very clear to me.
Can someone show some pointers?
Thanks in advance.
I built a battery circuit based on Maxim712 chip. I have attached my circuit and the board layout. I have set the charge time to 90 mins at 2 amps charging current. I have used BD 132 for fast charging.
I have serious problem with heat. Both my transistor and batteries become extremely hot. The transistor is connected to a decent heat sink. Data sheet show that max Ic for BD132 is 2 A. I measure 1.8 A flowing into the battery and around 1.4 V across each cell. I am bit worried that I might damage my batteries. I am using sony 2100mAh (four of them) batteries to charge.
Is my transistor getting hot bcoz I am close to its rating. Is is some other way to solve the heating issue. The data sheet shows the use of thermistors although its not very clear to me.
Can someone show some pointers?
Thanks in advance.
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