Charging Laptop (and other)batteries

From: Lawrence Walker <lgwalker_at_look.ca>
Date: Sat Apr 7 12:25:04 2001

 Thanks Joe and Tony. A further question is that some of the laptop batteries
have double positive and negative connection plates. Where these just to
ensure a good connection or are they actually 2 separate circuits. e.g.
2 6v in a 12 v pack ?

larry

> At 10:36 PM 4/5/01 -0400, larry wrote:
> > This is likely elementary but many times I run across the encased laptop
> >and other function(eg cordless drills) batteries. Of course each has it's
> own proprietory
> >charger which have long since disappeared and are costly to replace as
> well as being
> >device and company specific . Many of them have a 3rd terminal. What was
> it's
> >purpose.
> > Can you recharge these batteries simply by rigging up an interface using
> appropriate
> >voltages and polarity ? How would you deal with the 3rd terminal ?
> >
> >
>
> Larry,
>
> I'm assuming that your talking about NiCad batteries. If so, the third
> terminal is usually connected back to the * battery terminal via a thermal
> switch. The third terminal is used to recharge the batteries at a high
> current rate (Quick Charge). The thermal switch has to be in the circuit to
> prevent the batteries over heating and being damaged by the high current. You
> can go ahead charge the batteries at a normal 1/10 C (or lower) rate via the
> third terminal or the normal * terminal. The batteries will also last a lot
> longer if they're charged at 1/10 C instead "Quick Charged". The charge voltage
> isn't critical in NiCads but the charging current is important.
>
> Joe
>
>



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Received on Sat Apr 07 2001 - 12:25:04 BST